The Politics of Dementia

Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohort

Via The Lancet Public Health: Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohort. The summary:

Background  

Dementia and hearing loss are both highly prevalent conditions among older adults. We aimed to examine the association between hearing aid use and risk of all-cause and cause-specific dementia among middle-aged and older-aged adults, and to explore the roles of mediators and moderators in their association.  

Methods  

We used data from the UK Biobank, a population-based cohort study, which recruited adults aged 40–69 years between 2006 and 2010 across 22 centres in England, Scotland, and Wales. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% CIs between self-reported hearing aid use status (hearing loss with or without hearing aids) at baseline and risk of dementia (all-cause dementia, Alzheimer's disease, vascular dementia, and non-Alzheimer's disease non-vascular dementia). Dementia diagnoses were ascertained using hospital records and death-register data. We also analysed the roles of mediators (self-reported social isolation, loneliness, and mood) and moderators (self-reported education and income, smoking, morbidity, and measured APOE allele status).  

Findings  

After the exclusion of people who did not answer the question on hearing difficulties (n=25 081 [5·0%]) and those with dementia at baseline visit (n=283 [0·1%]), we included 437 704 people in the analyses. Compared with participants without hearing loss, people with hearing loss without hearing aids had an increased risk of all-cause dementia (HR 1·42 [95% CI 1·29–1·56]); we found no increased risk in people with hearing loss with hearing aids (1·04 [0·98–1·10]). The positive association of hearing aid use was observed in all-cause dementia and cause-specific dementia subtypes (Alzheimer's disease, vascular dementia, and non-Alzheimer's disease non-vascular dementia). The attributable risk proportion of dementia for hearing loss was estimated to be 29·6%. Of the total association between hearing aid use and all-cause dementia, 1·5% was mediated by reducing social isolation, 2·3% by reducing loneliness, and 7·1% by reducing depressed mood.  

Interpretation  

In people with hearing loss, hearing aid use is associated with a risk of dementia of a similar level to that of people without hearing loss. With the postulation that up to 8% of dementia cases could be prevented with proper hearing loss management, our findings highlight the urgent need to take measures to address hearing loss to improve cognitive decline.

Could Alzheimer’s be caused by an infection?

Via The Guardian: Could Alzheimer’s be caused by an infection? Excerpt:

As Davangere Devanand, a neurologist at Columbia University Medical Center, combed through the reams of scientific data on Alzheimer’s, he stumbled across a surprising idea – could an infection be involved in driving the disease?  

“I was looking for an Alzheimer’s treatment approach that had a reasonable shot of working,” he says. “I found this old theory, going back 35 years, which linked herpes viruses to the disease, and there were all these indirect lines of evidence.”  

The further Devanand looked, the more he found. Since the mid-80s, a handful of scientists around the world had doggedly pursued the idea that either a virus or a bacterium could play a role in Alzheimer’s, despite almost complete antipathy from those studying more accepted theories about the disease. Colleagues snubbed them, leading scientific journals and conferences rejected their work and funding had been threadbare, but slowly and surely, they built an increasingly compelling case.  

In particular, evidence pointed towards herpes simplex virus 1 (HSV-1) – a pathogen found in 70% of the UK population, and the cause of oral herpes – as a prominent suspect. Studies in the UK, France and Scandinavia suggested that people who had been infected with herpes were more likely to get Alzheimer’s.  

When Prof Ruth Itzhaki from Oxford University’s Institute of Population Ageing – who has done more than any other scientist to advance the HSV-1 theory of Alzheimer’s – examined postmortem brain samples from patients, she found greater amounts of the virus’s DNA than in people who had not died of the disease.  

“Then there was this 2018 study from Taiwan, which was quite dramatic,” says Devanand. “When people with herpes were treated with a standard antiviral drug, it decreased their risk of dementia nine-fold.”  

Devanand was intrigued because while the major hallmarks of Alzheimer’s are well-known, we still have little idea about what triggers it. We know that toxic plaques and tangles form inside the brain, causing damaging inflammation and the death of brain cells. Certain genes and lifestyle factors such as loneliness, lack of exercise and poor diet can all increase the risk of developing Alzheimer’s, but how and why it begins remains a mystery. Could a virus be the smoking gun that scientists have been looking for?  

Others have suggested that various bacteria may also be capable of initiating the neurodegeneration that leads to Alzheimer’s. Chlamydia pneumoniae, which causes lung disease, Borrelia burgdorferi, which is associated with Lyme disease, and even gum infections have all been put forward as possible triggers.  

The main idea for why viruses like HSV-1 and possibly bacteria may be capable of triggering Alzheimer’s is that they invade the body before burrowing into the central nervous system, and travelling to the brain sometime in midlife. Once there, they stay dormant for many years before being reactivated in old age, either because the ageing immune system can no longer keep them in check, or something else – a traumatic episode, a head injury or perhaps another infection – spurs them to life. Once awakened – so the theory goes – they begin to wreak havoc.  

For a long time, neurologists treated these ideas as fanciful, until more and more irrefutable evidence arose for the role of pathogens in chronic illness. Last year, the Epstein-Barr virus was identified as the main risk factor for multiple sclerosis, while other studies have shown that a bout of measles can lead many years later to a progressive neurological disorder called subacute sclerosing panencephalitis.  

So when Devanand approached the US National Institute on Aging for a grant of several million dollars to run a clinical trial investigating whether a herpes antiviral drug called valacyclovir could slow the progression of Alzheimer’s in patients in the early stages of the disease, they agreed to back him.

Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050

Via The Lancet Public Health: Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. The summary:

Background  

Given the projected trends in population ageing and population growth, the number of people with dementia is expected to increase. In addition, strong evidence has emerged supporting the importance of potentially modifiable risk factors for dementia. Characterising the distribution and magnitude of anticipated growth is crucial for public health planning and resource prioritisation. This study aimed to improve on previous forecasts of dementia prevalence by producing country-level estimates and incorporating information on selected risk factors.  

Methods  

We forecasted the prevalence of dementia attributable to the three dementia risk factors included in the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 (high body-mass index, high fasting plasma glucose, and smoking) from 2019 to 2050, using relative risks and forecasted risk factor prevalence to predict GBD risk-attributable prevalence in 2050 globally and by world region and country.  

Using linear regression models with education included as an additional predictor, we then forecasted the prevalence of dementia not attributable to GBD risks. To assess the relative contribution of future trends in GBD risk factors, education, population growth, and population ageing, we did a decomposition analysis.  

Findings  

We estimated that the number of people with dementia would increase from 57·4 (95% uncertainty interval 50·4–65·1) million cases globally in 2019 to 152·8 (130·8–175·9) million cases in 2050. Despite large increases in the projected number of people living with dementia, age-standardised both-sex prevalence remained stable between 2019 and 2050 (global percentage change of 0·1% [–7·5 to 10·8]).  

We estimated that there were more women with dementia than men with dementia globally in 2019 (female-to-male ratio of 1·69 [1·64–1·73]), and we expect this pattern to continue to 2050 (female-to-male ratio of 1·67 [1·52–1·85]).  

There was geographical heterogeneity in the projected increases across countries and regions, with the smallest percentage changes in the number of projected dementia cases in high-income Asia Pacific (53% [41–67]) and western Europe (74% [58–90]), and the largest in north Africa and the Middle East (367% [329–403]) and eastern sub-Saharan Africa (357% [323–395]).  

Projected increases in cases could largely be attributed to population growth and population ageing, although their relative importance varied by world region, with population growth contributing most to the increases in sub-Saharan Africa and population ageing contributing most to the increases in east Asia.  

Interpretation  

Growth in the number of individuals living with dementia underscores the need for public health planning efforts and policy to address the needs of this group. Country-level estimates can be used to inform national planning efforts and decisions.  

Multifaceted approaches, including scaling up interventions to address modifiable risk factors and investing in research on biological mechanisms, will be key in addressing the expected increases in the number of individuals affected by dementia.

Covid linked to longer-term elevated risk of brain fog and dementia

Via The Guardian: Covid linked to longer-term elevated risk of brain fog and dementia. Excerpt:

Millions of people who have had Covid-19 still face a higher risk of neurological and psychiatric conditions, including brain fog, dementia and psychosis, two years after their illness, compared with those who have had other respiratory infections, according to the single largest study of its kind.  

They also face an increased risk of anxiety and depression, the research suggests, but this subsides within two months of having Covid-19. Over two years the risk is no more likely than after other respiratory infections. The findings are published in the Lancet Psychiatry journal.  

Almost 600m Covid-19 cases have been recorded worldwide since the start of the pandemic, and there has been growing evidence that people who survive the disease face increased risks of neurological and psychiatric conditions.  

Previous studies have found that people face higher risks of several neurological and mental health conditions in the first six months after infection. Until now, however, there has been no large-scale data examining the risks over a longer time period. The new study, by the University of Oxford and the National Institute for Health and Care Research Oxford Health Biomedical Research Centre, analysed 1.28m Covid-19 cases over two years.  

Dr Max Taquet, who led the analyses at the University of Oxford, said: “The findings shed new light on the longer-term mental and brain health consequences for people following Covid-19 infection. The results have implications for patients and health services and highlight the need for more research to understand why this happens after Covid-19, and what can be done to prevent these disorders from occurring, or treat them when they do.”  

The study analysed data on 14 neurological and psychiatric diagnoses from electronic health records mostly from the US. It found that in adults the risk of depression or anxiety increased after Covid-19 but returned to the same as with other respiratory infections within about two months.

However, the risk of some other neurological and mental health conditions remained higher after Covid-19 than for other respiratory infections at the end of the two-year follow-up.  

Adults aged 64 and under who had Covid-19 had a higher risk of brain fog (640 cases per 10,000 people) compared with those who had other respiratory infections (550 cases per 10,000 people).  

In those aged 65 and over who had Covid-19, there was a higher occurrence of brain fog (1,540 cases per 10,000 people), dementia (450 cases per 10,000 people) and psychotic disorders (85 cases per 10,000 people) compared with those who previously had a different respiratory infection (1,230 cases per 10,000 for brain fog, 330 cases per 10,000 for dementia and 60 cases per 10,000 for psychotic disorder).

Air pollution is ‘likely’ to raise dementia risk, find UK government experts

Via The Guardian: Air pollution is ‘likely’ to raise dementia risk, find UK government experts. Excerpt:

Air pollution is likely to increase the risk of developing dementia, a government research group has said.  

The Committee on the Medical Effects of Air Pollutants has published its findings after reviewing almost 70 studies that analysed how exposure to emissions affect the brain over time.  

The 291-page report concludes that air pollution is likely to increase the risk of accelerated “cognitive decline” and of “developing dementia” in older people.  

Experts believe this is due to the impact of pollutants entering the circulatory system, affecting blood flow to the brain.  

The authors said: “The epidemiological evidence reviewed fairly consistently reports associations between chronic exposure to air pollution and reduced global cognition and impairment in visuospatial abilities as well as cognitive decline and increased risk of dementia. 

“Results are heterogeneous as regards to other cognitive domains such as executive function, attention, memory, language and mild cognitive impairment. The identified neuroimaging studies consistently report associations between exposure to air pollution and white matter atrophy.” 

It adds that studies are split over which pollutant is most associated with these effects.  

The committee said it had made recommendations for further research to help develop the evidence.  

About 850,000 people in the UK suffer with dementia, according to the NHS.

Known risks for Alzheimer's and related dementias—and how I'm dealing with them

Thanks to Ian Kremer for sending the link to this CDC report: Modifiable Risk Factors for Alzheimer Disease and Related Dementias Among Adults Aged ≥45 Years — United States, 2019. The summary and then some comments:

What is already known about this topic?  

The 2021 National Plan to Address Alzheimer’s Disease (National Plan) included a goal to reduce the risk for Alzheimer disease and related dementias (ADRD).  

What is added by this report?  

Adults aged ≥45 years with subjective cognitive decline (SCD) were more likely to report four or more risk factors compared with those without SCD (34.3% versus 13.1%). Prevalence of SCD increased from 3.9% among adults with no risk factors to 25.0% among those with four or more risk factors.  

What are the implications for public health practice?  

Implementing evidence-based strategies that address modifiable risk factors can help achieve the National Plan’s goal to reduce risk for ADRD while promoting healthy aging.

At 81, I'm keenly aware of these risk factors. Here's how I'm dealing with them:

Aerobic activity: My Aussie shepherd Perri gets me out for 3 km or more of walking every day.

Cigarette smoking: I quit 40 years ago, after growing up in a household where everyone smoked.

Excessive alcohol use: After decades of enjoying beer, I quit in January. I'm on so many medications now that alcohol is more of a hazard than a solace.

Obesity: Not  an issue. The stress of a compression fracture in December seems to have driven a dramatic weight loss, from 184 pounds to about 158 in a month. Osteoporosis is not a good way to lose weight. Now back up to about 165, and would like to add another 10 or so.

Hypertension: Taking medications for it since my stroke in 2012. Under control.

Diabetes: My GP says I'm right on the edge, so I'm taking a metformin with every meal.

Depression: Not an issue. Maybe I'm not responding to the pandemic, climate collapse, and the war in Ukraine as seriously as I should.

Hearing loss: This is a problem. I can't afford hearing aids at the moment, but hope to be able to before too much longer. It's not good to be sealed off from the auditory world. 

So that's one risk factor instead of four or more. Not great, but not as bad as it might be. I'm also encouraged by the fact that neither my wife nor I have had COVID yet.

Healthy lifestyle and life expectancy with and without Alzheimer’s dementia: population based cohort study

Thanks to Dr. Morley Lertzman for sending the link to this article in The BMJ: Healthy lifestyle and life expectancy with and without Alzheimer’s dementia: population based cohort study. The abstract;

Objective To determine the impact of lifestyle factors on life expectancy lived with and without Alzheimer’s dementia.  Design Prospective cohort study.  

Setting The Chicago Health and Aging Project, a population based cohort study in the United States.  

Participants 2449 men and women aged 65 years and older.  

Main exposure A healthy lifestyle score was developed based on five modifiable lifestyle factors: a diet for brain health (Mediterranean-DASH Diet Intervention for Neurodegenerative Delay—MIND diet score in upper 40% of cohort distribution), late life cognitive activities (composite score in upper 40%), moderate or vigorous physical activity (≥150 min/week), no smoking, and light to moderate alcohol consumption (women 1-15 g/day; men 1-30 g/day).  

Main outcome Life expectancy with and without Alzheimer’s dementia in women and men.  

Results Women aged 65 with four or five healthy factors had a life expectancy of 24.2 years (95% confidence interval 22.8 to 25.5) and lived 3.1 years longer than women aged 65 with zero or one healthy factor (life expectancy 21.1 years, 19.5 to 22.4). Of the total life expectancy at age 65, women with four or five healthy factors spent 10.8% (2.6 years, 2.0 to 3.3) of their remaining years with Alzheimer’s dementia, whereas women with zero or one healthy factor spent 19.3% (4.1 years, 3.2 to 5.1) with the disease.  

Life expectancy for women aged 65 without Alzheimer’s dementia and four or five healthy factors was 21.5 years (20.0 to 22.7), and for those with zero or one healthy factor it was 17.0 years (15.5 to 18.3).  

Men aged 65 with four or five healthy factors had a total life expectancy of 23.1 years (21.4 to 25.6), which is 5.7 years longer than men aged 65 with zero or one healthy factor (life expectancy 17.4 years, 15.8 to 20.1). Of the total life expectancy at age 65, men with four or five healthy factors spent 6.1% (1.4 years, 0.3 to 2.0) of their remaining years with Alzheimer’s dementia, and those with zero or one healthy factor spent 12.0% (2.1 years, 0.2 to 3.0) with the disease.  

Life expectancy for men aged 65 without Alzheimer’s dementia and four or five healthy factors was 21.7 years (19.7 to 24.9), and for those with zero or one healthy factor life expectancy was 15.3 years (13.4 to 19.1). 

Conclusion A healthy lifestyle was associated with a longer life expectancy among men and women, and they lived a larger proportion of their remaining years without Alzheimer’s dementia.  

The life expectancy estimates might help health professionals, policy makers, and stakeholders to plan future healthcare services, costs, and needs.

Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: An analysis for the Global Burden of Disease Study 2019

Via The Lancet Public Health: Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. See also the editorial, posted just below. The summary:

Background  

Given the projected trends in population ageing and population growth, the number of people with dementia is expected to increase. In addition, strong evidence has emerged supporting the importance of potentially modifiable risk factors for dementia. Characterising the distribution and magnitude of anticipated growth is crucial for public health planning and resource prioritisation. This study aimed to improve on previous forecasts of dementia prevalence by producing country-level estimates and incorporating information on selected risk factors.  

Methods  

We forecasted the prevalence of dementia attributable to the three dementia risk factors included in the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 (high body-mass index, high fasting plasma glucose, and smoking) from 2019 to 2050, using relative risks and forecasted risk factor prevalence to predict GBD risk-attributable prevalence in 2050 globally and by world region and country. 

Using linear regression models with education included as an additional predictor, we then forecasted the prevalence of dementia not attributable to GBD risks. To assess the relative contribution of future trends in GBD risk factors, education, population growth, and population ageing, we did a decomposition analysis.  

Findings  

We estimated that the number of people with dementia would increase from 57·4 (95% uncertainty interval 50·4–65·1) million cases globally in 2019 to 152·8 (130·8–175·9) million cases in 2050. Despite large increases in the projected number of people living with dementia, age-standardised both-sex prevalence remained stable between 2019 and 2050 (global percentage change of 0·1% [–7·5 to 10·8]). We estimated that there were more women with dementia than men with dementia globally in 2019 (female-to-male ratio of 1·69 [1·64–1·73]), and we expect this pattern to continue to 2050 (female-to-male ratio of 1·67 [1·52–1·85]). There was geographical heterogeneity in the projected increases across countries and regions, with the smallest percentage changes in the number of projected dementia cases in high-income Asia Pacific (53% [41–67]) and western Europe (74% [58–90]), and the largest in north Africa and the Middle East (367% [329–403]) and eastern sub-Saharan Africa (357% [323–395]).  

Projected increases in cases could largely be attributed to population growth and population ageing, although their relative importance varied by world region, with population growth contributing most to the increases in sub-Saharan Africa and population ageing contributing most to the increases in east Asia. Interpretation  

Growth in the number of individuals living with dementia underscores the need for public health planning efforts and policy to address the needs of this group. Country-level estimates can be used to inform national planning efforts and decisions. Multifaceted approaches, including scaling up interventions to address modifiable risk factors and investing in research on biological mechanisms, will be key in addressing the expected increases in the number of individuals affected by dementia.

Will dementia hamper healthy ageing?

Via The Lancet Public Health: Will dementia hamper healthy ageing?

During Jan 24–29, 2022, the 150th session of the WHO Executive Board will be held, and members will agree upon the agenda and resolutions to be considered by the World Health Assembly. An important initiative will be presented as part of so-called Pillar 3 (1 billion more people enjoying better health and wellbeing): healthy ageing. In December, 2020, the UN General Assembly declared 2021–30 the Decade of Healthy Ageing, and WHO is tasked to coordinate this initiative and provide strategic leadership on demographic change and healthy ageing. Today, there are more than 1 billion people aged 60 years or older. Around the world, populations are ageing and this demographic transition will affect almost all aspects of society.  

One condition, in particular, could well challenge WHO's and the UN's ambitions: dementia. Dementia is one of the major causes of disability and dependency among older people and, according to the Global Burden of Disease (GBD) study published in this issue of The Lancet Public Health, dementia cases are projected to triple by 2050 unless countries address risk factors.  

In their study, Emma Nichols and collaborators forecast dementia prevalence in 204 countries and territories and examine the impact of expected trends in exposure to selected, important risk factors. Nichols and colleagues estimate that the number of adults living with dementia worldwide is expected to increase from an estimated 57 million in 2019 to 153 million in 2050, due primarily to population growth and population ageing. The authors considered four risk factors for dementia—high blood sugar, smoking, obesity, and low education—and their potential effect on future trends, and report that improvements in education could reduce dementia prevalence by 6·2 million cases by 2050, but this could be countered by projected trends in obesity, high blood sugar, and smoking, which are expected to contribute an additional 6·8 million dementia cases.  

Moreover, dementia cases are projected to increase in every country, but there are substantial geographical heterogeneity and important differences in the estimated changes in age-standardised prevalence across Socio-demographic Index quintiles.

This study is particularly important for several reasons. First, for policy locally. Country-level estimates can be used to inform national planning and decision making to ensure resources and support are available for individuals, carers, and health systems.

Second, for prevention and the importance of potentially modifiable risk factors. The 2020 Lancet Commission on dementia estimated that 40% of dementia cases could be prevented or delayed if exposure to 12 known risk factors were eliminated: high blood pressure, smoking, obesity, low education, depression, diabetes, physical inactivity, hearing impairment, social isolation, excessive alcohol consumption, head injury, and air pollution. 

Tackling these risk factors goes well beyond individuals' behaviours and will need addressing the economic and social determinants of health. For Theo Vos, coauthor of the study, ”Ensuring that structural inequalities in access to health and social care services can be addressed and that services can additionally be adapted to the unprecedented needs of an increasing older population with complex care needs will require considerable planning at both local and national levels.” 

Finally, this GBD study provides a stark reminder that such growth in the number of individuals living with dementia underscores the need for very strong public health responses. In September, 2021, WHO reported on the progress of the public health response to dementia—as part of the Global Action Plan (2017–25), which aims to decrease the burden of dementia and improve the lives of individuals living with dementia and their carers. Halfway through this plan, some progress has been made, but too few countries have a national plan to prevent, mitigate, and manage dementia. 

For Hilary Evans, Chief Executive of Alzheimer's Research UK, “Dementia doesn't just affect individuals, it can devastate whole families and networks of friends and loved ones. The heart-breaking personal cost of dementia goes hand-in-hand with huge economic and societal impacts, strengthening the case to governments across the world to do more to protect lives now and in the future.” 

Dementia is a major and rapidly growing threat to healthy ageing and social care systems in every country. Investing in an adequate public health response to dementia and healthy ageing, with health equity at its core, needs to start now.

Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050

Via The Lancet Public Health: Estimation of the global prevalence of dementia in 2019 and forecasted prevalence in 2050: an analysis for the Global Burden of Disease Study 2019. The summary and then another link and a comment: 

Background  

Given the projected trends in population ageing and population growth, the number of people with dementia is expected to increase. In addition, strong evidence has emerged supporting the importance of potentially modifiable risk factors for dementia. Characterising the distribution and magnitude of anticipated growth is crucial for public health planning and resource prioritisation. This study aimed to improve on previous forecasts of dementia prevalence by producing country-level estimates and incorporating information on selected risk factors.  

Methods  

We forecasted the prevalence of dementia attributable to the three dementia risk factors included in the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 (high body-mass index, high fasting plasma glucose, and smoking) from 2019 to 2050, using relative risks and forecasted risk factor prevalence to predict GBD risk-attributable prevalence in 2050 globally and by world region and country. Using linear regression models with education included as an additional predictor, we then forecasted the prevalence of dementia not attributable to GBD risks. To assess the relative contribution of future trends in GBD risk factors, education, population growth, and population ageing, we did a decomposition analysis.  

Findings  

We estimated that the number of people with dementia would increase from 57·4 (95% uncertainty interval 50·4–65·1) million cases globally in 2019 to 152·8 (130·8–175·9) million cases in 2050. Despite large increases in the projected number of people living with dementia, age-standardised both-sex prevalence remained stable between 2019 and 2050 (global percentage change of 0·1% [–7·5 to 10·8]). We estimated that there were more women with dementia than men with dementia globally in 2019 (female-to-male ratio of 1·69 [1·64–1·73]), and we expect this pattern to continue to 2050 (female-to-male ratio of 1·67 [1·52–1·85]). 

There was geographical heterogeneity in the projected increases across countries and regions, with the smallest percentage changes in the number of projected dementia cases in high-income Asia Pacific (53% [41–67]) and western Europe (74% [58–90]), and the largest in north Africa and the Middle East (367% [329–403]) and eastern sub-Saharan Africa (357% [323–395]). v

Projected increases in cases could largely be attributed to population growth and population ageing, although their relative importance varied by world region, with population growth contributing most to the increases in sub-Saharan Africa and population ageing contributing most to the increases in east Asia.  

Interpretation  

Growth in the number of individuals living with dementia underscores the need for public health planning efforts and policy to address the needs of this group. Country-level estimates can be used to inform national planning efforts and decisions. Multifaceted approaches, including scaling up interventions to address modifiable risk factors and investing in research on biological mechanisms, will be key in addressing the expected increases in the number of individuals affected by dementia.

See also this comment on the study. It offers the cold comfort of assuming the numbers of old people with dementia will be smaller than the study predicts—because the current pandemic will have killed many of them before dementia appears.

Number of people with dementia set to jump 40% to 78 mln by 2030 -WHO

Via Reuters: Number of people with dementia set to jump 40% to 78 mln by 2030 -WHO. Excerpt:

GENEVA, Sept 2 (Reuters) - More than 55 million people worldwide are living with dementia, a neurological disorder that robs them of their memory and costs the world $1.3 trillion a year, the World Health Organization (WHO) said on Thursday. 

The progressive condition can be caused by stroke, brain injury or Alzheimer's disease. With populations ageing, the number of sufferers is projected to rise to 78 million by 2030 and 139 million by 2050, the WHO said in a report. 

Only one in four countries has a national policy in place to support dementia patients and their families, it said, urging governments to step up to the public health challenge. 

"Dementia robs millions of people of their memories, independence and dignity, but it also robs the rest of us of the people we know and love," said Tedros Adhanom Ghebreyesus, WHO director-general.

"The world is failing people with dementia, and that hurts all of us," he said. 

Health ministers agreed in 2015 on a global action plan, including early diagnosis and providing care, but are falling short on meeting targets by 2025, it said.

"Dementia truly is a global public health concern and not just in high-income countries. In fact, over 60% of people with dementia live in low- and middle-income countries," Katrin Seeher, an expert in WHO's department of mental health, told a news briefing. 

Medication, hygiene products and household adjustments for dementia patients are more accessible in wealthy countries, which have a greater level of reimbursement than in lower-income countries, the report said.

The mystery of 9/11 first responders and dementia

Via The Washington Post: The mystery of 9/11 first responders and dementia. Excerpt:

More than a decade after the twin towers fell, Ron Kirchner began forgetting things. Buckling his belt. Closing his car door. Once, while visiting a preschool class on the 13th anniversary of 9/11, he even neglected to wear his customary necktie and New York City Fire Department hat. “He was in a panic,” says his wife, Dawn. “He used to like to bring the kids something, like coloring books. And he couldn’t find anything.” 

This was unlike Ron, who had always been devoted and dutiful. He frequently wrote Dawn love notes, hiding them around their house. He made time after work to play with his two children, Luke and Ava. He mopped the floors before going to bed, whistling while he pushed the handle. “He did it joyfully,” Dawn says. “Ronnie was a giver.” 

Ron brought the same enthusiasm to his job as a firefighter in Queens, where he obsessively cleaned his truck, stayed up all night waiting for calls, and — according to unit lore — once smashed an Xbox with an ax because he thought that some of his younger colleagues were spending too much time playing video games. “Dad thought they should be reading up on fire stuff, training and procedures,” Luke says with a laugh. 

Ron was one of the tens of thousands of police, firefighters, construction workers and others who worked amid the ruins of the World Trade Center in Lower Manhattan following 9/11. Like many of those responders, he later paid a price. Diagnosed with asthma and a lung disease both linked to Ground Zero exposure, Ron retired on disability in 2009 and moved to Arizona. 

At first, life in the desert was good. Ron landed a comfortable job working private security for a wealthy client. He and Dawn visited the Grand Canyon. They saw the red rocks of Sedona. Ron would wheeze while hiking, and sometimes at night, but a nebulizer made his breathing less strained. 

By 2014, however, Ron’s troubles with thinking and memory were becoming unmanageable. Back in New York, he had deftly maneuvered a fire engine along the city’s crowded streets; now, he struggled to parallel park the family’s SUV inside two spaces. He would put toothpaste on his toothbrush and not know what to do with it. He was let go from his security job — in part, Dawn says, because he struggled to use a smartphone. 

One day in early 2015, Dawn received a call from her husband’s naturopathic doctor, who had given Ron the Montreal Cognitive Assessment, a brief test that screens patients for cognitive disorders. Ron had scored poorly, unable to draw a simple clock face with the correct time. Dawn took him to a neurologist, who diagnosed him with dementia. Ron was 51. The neurologist, Dawn says, told her that a magnetic resonance imaging scan of his brain was comparable to that of an 85-year-old. 

Today, Ron suffers from seizures. He can no longer speak coherently, cut his own food or bathe himself. He requires round-the-clock care and supervision from his wife and children, lest he wander into the streets around his family’s home in Oceanside, N.Y., where they moved in 2017. 

“He doesn’t really know who I am,” Dawn says, “or who he is, or what his favorite thing in the world — the fire department — is.” 

She doesn’t think Ron knew he was being photographed for this article, and believes it would have been impossible to explain it to him. But Dawn feels that it’s important to share his story as a way of helping others — and that her husband, if he could still understand, would feel the same. 

Ron’s condition is almost unheard of for a 59-year-old man, and it points to an emerging medical mystery: Twenty years after 9/11, Ground Zero first responders are suffering from abnormally high rates of cognitive impairment, with some individuals in their 50s experiencing deficiencies that typically manifest when people are in their 70s — if at all. 

“That is the most extraordinary thing with these cognitive issues, and what blows me away,” says Benjamin Luft, director of Stony Brook University’s World Trade Center Health and Wellness Program, which cares for and studies responders. “You don’t expect this to occur in your 50s, because it doesn’t occur. And a lot of these people are in their early 50s.” 

Although most cases are not as severe as Ron’s, the number of responders showing memory loss and other signs of impairment has been rising over time. Scientists and doctors are now asking: Is 9/11 to blame?

WHO: World failing to address dementia challenge

A news release from WHO: World failing to address dementia challenge. Excerpt:

Only a quarter of countries worldwide have a national policy, strategy or plan for supporting people with dementia and their families, according to the WHO’s ‘Global status report on the public health response to dementia’, released today. Half of these countries are in WHO’s European Region, with the remainder split between the other Regions. Yet even in Europe, many plans are expiring or have already expired, indicating a need for renewed commitment from governments. 

At the same time, the number of people living with dementia is growing according to the report: WHO estimates that more than 55 million people (8.1 % of women and 5.4% of men over 65 years) are living with dementia. This number is estimated to rise to 78 million by 2030 and to 139 million by 2050. 

Dementia is caused by a variety of diseases and injuries that affect the brain, such as Alzheimer’s disease or stroke. It affects memory and other cognitive functions, as well as the ability to perform everyday tasks. The disability associated with dementia is a key driver of costs related to the condition. In 2019, the global cost of dementia was estimated to be US$ 1.3 trillion. The cost is projected to increase to US$ 1.7 trillion by 2030, or US$ 2.8 trillion if corrected for increases in care costs. 

“Dementia robs millions of people of their memories, independence and dignity, but it also robs the rest of us of the people we know and love,” said Dr Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization. 

“The world is failing people with dementia, and that hurts all of us. Four years ago, governments agreed a clear set of targets to improve dementia care. But targets alone are not enough. We need concerted action to ensure that all people with dementia are able to live with the support and dignity they deserve.”

Scientists warn that Covid will accelerate ‘dementia pandemic’

Via the Financial Times: Scientists warn that Covid will accelerate ‘dementia pandemic’.

The degenerative effect on the brain of coronavirus will add fuel to the “pandemic of dementia” that will affect an estimated 80m by the end of the decade, scientists and psychiatrists have warned. 

Alzheimer’s Disease International, the global federation of dementia associations, on Wednesday unveiled a specialist working group to understand better the scale of the problem and recommend ways to combat it. 

“We don’t want to scare people unnecessarily,” said Paola Barbarino, ADI chief executive, “but many dementia experts around the globe are seriously concerned by the link between dementia and the neurological symptoms of Covid-19”. 

Alireza Atri, a cognitive neurologist and chair of ADI’s medical and scientific advisory panel, continued: “Covid-19 can cause damage and clotting in the brain’s micro vessels, immune dysfunction and hyperactivation, inflammation, and, last but not least, direct viral brain invasion through the olfactory pathways. 

“While there is still a way to go in understanding this, we know that anything that diminishes your cognitive reserve and resilience is going to allow neurodegenerative processes to accelerate, which can cause symptoms of neurological disorders, such as dementia, to show earlier.” 

There is mounting evidence that Covid-19 can cause long-term brain damage. One piece is that similar biochemical changes are observed in some coronavirus patients and in people with Alzheimer’s — indicating neuronal injury and inflammation.

Another is the growing number of studies showing that many people with so-called long-Covid suffer from cognitive problems including “brain fog” as well as difficulties with memory, concentration and language. In most patients, such symptoms are expected to resolve themselves over time but the fear is that it may tip some into progressive dementia. 

Besides formal scientific studies, clinicians such as Atri and Gill Livingston, professor of psychiatry at University College London, say they have noticed more patients whose dementia is progressing unexpectedly fast after coronavirus. 

To make matters worse, Livingston said, “increased isolation because of Covid and social distancing is itself a risk factor for dementia. People are missing the cognitive stimulation that can help delay the onset of symptoms.” 

Epidemiologists point out that Covid-19 would not be unusual among viral infections in causing progressive neurological disorders. The 1918 Spanish flu increased survivors’ long-term risk of developing Parkinson’s disease by a factor of two to three, Barbarino pointed out. Paola Barbarino of the Alzheimer’s Disease International warns of an ‘oncoming pandemic of dementia’ © Pete Jones/ADI 

Some 55m people are currently living with dementia, according to World Health Organization estimates, which is predicted to rise to about 80m by 2030 as the elderly population increases. 

Though it is too soon to quantify the exact effect of Covid-19 on future dementia cases, “it could have a large impact”, said Atri, who is also director of the Banner Sun Health Research Institute in Arizona. “This is a nasty, vicious virus and I’m sure it will tip some people over into dementia sooner than would otherwise be the case.” 

Barbarino urged “the WHO, governments and research institutions across the globe to prioritise and commit more funding to research and establish resources . . . to avoid being further overwhelmed by the oncoming pandemic of dementia”.

Can older adults walk their way out of dementia?

Via Medscape Medical News: Can Older Adults Walk Their Way Out of Dementia? Excerpt:

DENVER ― Low to moderate levels of physical activity in later life significantly mitigate the increased risk for age-related dementia, new research suggests. 

New data from the English Longitudinal Study of Aging (ELSA) show that adults aged 80 years and older who engaged in moderate to high levels of physical activity were at lower risk for all-cause dementia than inactive adults who were in their 50s and 60s. 

"These findings have important public health implications, because we know that age is the strongest risk factor for all-cause dementia and sedentary behaviors are increasing, both in younger people and older people who may have difficulties in achieving the recommended levels of physical activity," said lead investigator Natan Feter, PhD, Federal University of Pelotas, in Pelotas, Brazil. 

"Even moderate-intensity physical activity once per week can reduce the risk of dementia. We had previously shown this effect on people with mild cognitive impairment. Here, we showed this effect for the overall older population," Feter told Medscape Medical News. 

The findings were presented here at the Alzheimer's Association International Conference (AAIC) 2021. 

Attenuating, Eliminating Risk 

As part of the ELSA study, adults aged 50 years and older were followed between 2002 and 2019. On the basis of responses to a validated questionnaire, participants were classified as being inactive or engaging in low or moderate to high levels of physical activity. 

Feter reported data for 8270 ELSA participants (mean age, 64 years; 56% women). 

Over 17 years of follow-up, about 8% of these participants developed dementia. The risk for dementia increased by 7.8% for each year increase in age.

However, risk for all-cause dementia was reduced for those who engaged in low (odds ratio [OR], 0.30; 95% CI, 0.25 – 0.36) and moderate to high (OR, 0.13; 95% CI, 0.10 – 0.16) levels of physical activity compared with their inactive peers.

Feter said it is particularly noteworthy that adults aged 80 and older who engaged in moderate to high levels of physical activity were at lower risk for dementia than inactive adults aged 50 to 69 years.

"In our opinion, this is the study's main finding," he said.

Although aging is the strongest risk factor for dementia, "we showed that moderate-intensity physical activity once per week can attenuate, or even eliminate, the risk of dementia associated with aging," Feter noted. "In fact, older adults engaging in regular physical activity have a lower risk of dementia than adults aged up to 30 years younger."

However, he noted several study limitations, including the way that physical activity and dementia were assessed and that reverse causality and residual confounding "might not be ruled out from our findings."

Speech‐in‐noise hearing impairment is associated with an increased risk of incident dementia in 82,039 UK Biobank participants

Via Alzheimer's & Dementia: Speech‐in‐noise hearing impairment is associated with an increased risk of incident dementia in 82,039 UK Biobank participants. The abstract:

Introduction 

Little is known about the association between speech-in-noise (SiN) hearing impairment and dementia. 

Methods 

In 82,039 dementia-free participants aged ≥60 years were selected from the UK Biobank. Cox proportional-hazards models were used to investigate whether SiN hearing impairment is associated with an increased risk of incident dementia. 

Results 

Over 11 years of follow-up (median = 10.1), 1285 participants developed dementia. Insufficient and poor SiN hearing were associated with a 61% (hazard ratio [HR] = 1.61, 95% confidence [CI] 1.41–1.84) and 91% (HR = 1.91, 95% CI 1.55–2.36) increased risk of developing dementia, respectively, compared to normal SiN hearing. The association remained similar when restricting to follow-up intervals of ≤3, >3 to  <6, >6 to <9, and >9 years. There was limited evidence for mediation through depressive symptoms and social isolation. 

Discussion 

SiN hearing impairment is independently associated with incident dementia, providing further evidence for hearing impairment as a potential modifiable dementia risk factor.

FDA grants historic approval to Alzheimer’s drug from Biogen

Via STAT: FDA grants historic approval to Alzheimer’s drug from Biogen. Excerpt:

The Food and Drug Administration on Monday approved the first new treatment for Alzheimer’s disease in nearly two decades, a landmark decision that has been eagerly awaited by millions of Americans diagnosed with the condition but that will be hotly contested by some in the scientific community who doubt the drug’s effectiveness. 

 While other drugs treat symptoms of Alzheimer’s, the new medicine, called Aduhelm, is the first to attack what some believe is an underlying cause of the disease and slow cognitive decline, albeit marginally. It does so by eliminating clumps of a toxic protein believed to destroy neurons and cause dementia. Aduhelm is not a cure for Alzheimer’s, and it doesn’t reverse the disease’s progression. 

The drug — which just two years ago was declared a stunning failure — is now expected to generate billions of dollars in revenue for its maker, Biogen. 

“This historic moment is the culmination of more than a decade of groundbreaking research in the complex field of Alzheimer’s disease,” Biogen CEO Michel Vounatsos said in a statement. “We believe this first-in-class medicine will transform the treatment of people living with Alzheimer’s disease and spark continuous innovation in the years to come.” 

But the approval of Aduhelm, also known by its scientific name aducanumab, is all but sure to become one of the most controversial and disputed decisions on a drug application in recent years. The FDA granted marketing clearance to the drug over the strong objections of a panel of independent experts it convened in November. Those advisers reviewed Biogen’s clinical data and concluded overwhelmingly that there was insufficient evidence that the treatment had significant benefits for patients. They argued the drug should not be approved, as have many outside experts. Others saw enough evidence of efficacy — and a desperate need for new treatments. 

Instead of judging Biogen’s treatment solely on its effects on cognition, the FDA granted a conditional approval based on Aduhelm’s ability to clear the toxic proteins, called beta-amyloid. In order to continue marketing the drug, Biogen will need to complete a large clinical trial to confirm that removing the plaque has cognitive benefits, the FDA said. If that study fails, the FDA has the authority to rescind its approval. 

In approving the drug on a conditional basis, the agency departed from decades of regulatory precedent, setting a new bar for treatments with considerable potential but unproven benefits — a standard that could also be applied to other devastating diseases. 

“I’m quite surprised. The most compelling argument for approval was the unmet need but that cannot, or should not, trump regulatory standards,” said Caleb Alexander, a Johns Hopkins epidemiologist who served on the FDA’s advisory panel and voted against the approval of Aduhelm. “It’s hard to find any scientist who thinks the data are persuasive. Unmet need is an important contextual factor but it’s not an evidentiary threshold.” 

Aduhelm’s development has sharply divided Alzheimer’s experts. Now that Aduhelm is approved, they face a new challenge: prescribing the drug without overselling its effects. 

“For patients who qualify, I’m hopeful for them,” said Ronald Petersen, a neurologist who leads the Mayo Clinic Alzheimer’s Disease Research Center. “Now we have a potential treatment for them that may modify the underlying disease course. But the largest responsibility for us is to educate patients and physicians as to what this means. This is not going to be penicillin for Alzheimer’s disease.”

Dementia patients are at greater risk for COVID-19, particularly African Americans and people with vascular dementia

Via The Conversation: Dementia patients are at greater risk for COVID-19, particularly African Americans and people with vascular dementia. Excerpt:

New research is shedding light on how dementia can increase people’s risk for developing COVID-19, particularly among two groups: African Americans and people with vascular dementia. 

The headline findings of a recent study revealed that dementia patients overall face twice the risk for developing COVID-19 as adults without dementia. But two other results from that study deserve more attention than they have received so far. 

One is that African Americans with dementia had three times the risk of developing COVID-19, and when they did, it was more likely to be life-threatening. African Americans with both dementia and COVID-19 had a higher hospitalization rate than white patients with dementia – 73% compared with 54% – and a higher death rate – 23% compared with 19% for whites. In view of the health disparities already borne by people of color, this is particularly troubling. 

The study also found that patients with vascular dementia had the highest risk among dementia patients for COVID-19. This type of dementia is associated with strokes or small blood vessel damage, resulting in lower blood flow to the brain’s white matter, and injuries to the connections among neurons. This damage is visible on MRI scans. If enough damage occurs, cognitive function can be impaired.

Gait variability across neurodegenerative and cognitive disorders

Via Alzheimer's & Dementia: Gait variability across neurodegenerative and cognitive disorders: Results from the Canadian Consortium of Neurodegeneration in Aging (CCNA) and the Gait and Brain Study. The abstract:

Introduction 

Gait impairment is common in neurodegenerative disorders. Specifically, gait variability—the stride‐to‐stride fluctuations in distance and time—has been associated with neurodegeneration and cognitive impairment. However, quantitative comparisons of gait impairments across the cognitive spectrum of dementias have not been systematically investigated. 

Methods 

Older adults (N = 500) with subjective cognitive impairment, Parkinson disease (PD), mild cognitive impairment (MCI), PD‐MCI, Alzheimer's disease (AD), PD‐dementia, Lewy body dementia, and frontotemporal dementia, as well cognitive normal controls, who were assessed for their gait and cognitive performance. 

Results 

Factor analyses grouped 11 quantitative gait parameters and identified four independent gait domains: rhythm, pace, variability, and postural control, for group comparisons and classification analysis. Among these domains, only high gait variability was associated with lower cognitive performance and accurately discriminated AD from other neurodegenerative and cognitive conditions. 

Discussion 

Our findings indicate that high gait variability is a marker of cognitive‐cortical dysfunction, which can help to identify Alzheimer's disease dementia.

COVID-19: ‘We are going to keep you safe, even if it kills your spirit’

An opinion piece in The New York Times: ‘We Are Going to Keep You Safe, Even if It Kills Your Spirit’. Excerpt:

On a recent morning, Bill Williams, 87, awoke to learn of a terrible virus that had spread everywhere and was killing people. “Well, we’ve got this virus,” an aide at his nursing home in Broken Bow, Neb., told him. A few minutes later, he had forgotten about the virus, and so the nursing aide told him again. And then again. She would have to tell him the next day, too. 

“It’s pretty quiet in here,” Mr. Williams said, biting the inside of his lip a little. 

“Well, we’ve got this virus.” 

On most days, after Mr. Williams forgets again about the virus, he gets out of his armchair and into his wheelchair and goes down the hallway at Brookestone View Skilled Nursing and Rehabilitation. Like other residents with Alzheimer’s disease or dementia, he is “noncompliant” with mask-wearing protocols. He says the masks fog up his glasses. Or he thinks: What mask? He is also “noncompliant” with social-distancing measures. 

In other care facilities and in hospitals, too, “wanderers” with dementia are believed to have spread the virus and caused outbreaks — but what are administrators to do? They can’t just lock people up. 

“Stay in your room,” the nursing aides tell Mr. Williams. But he doesn’t stay. Whenever he gets out, an aide redirects him back to his armchair. Then again and again, until someone gets exasperated and lets him sit in the hallway for a while, so that he can watch the comings and goings. 

Because the thing is, it’s boring to sit in an armchair all day — even though Mr. Williams, a former crop duster, likes to watch planes taking off from a nearby airstrip, through his window. The dining hall is closed. Visitors are mostly prohibited. “Life enrichment” activities, like bingo, have been canceled. Mr. Williams knows that the choreography of the nursing home is off, but he isn’t sure why. “Everybody got busy doing stuff, I guess,” he told me.