Cancer Survivors May Have Lower Odds for Dementia

Amy Norton wrote . . . . . . . . .

Researchers have found more evidence of a puzzling phenomenon: Older adults who survive cancer seem to be somewhat protected against dementia.

A number of studies in recent years have found that cancer survivors have a relatively lower risk of developing Alzheimer’s.

The new research adds another layer. It shows that even before their diagnosis, older adults who go on to develop cancer have an edge when it comes to memory performance.

Among the older Americans who were tracked for 16 years, those who developed cancer typically had sharper memory skills — both before and after the diagnosis — than those who remained cancer-free.

Researchers said it all supports the theory that some of the biological processes that contribute to cancer may actually protect against dementia.

But the big remaining question is, what are those mechanisms?

“We’re really interested in understanding what [they] could be, because it might point the way to strategies to prevent dementia,” said senior researcher Maria Glymour, a professor at the University of California, San Francisco School of Medicine.

The study findings are based on more than 14,500 U.S. adults born before 1949. Between 1998 and 2014, they underwent periodic tests of memory function. During that time, 2,250 were newly diagnosed with cancer.

On average, the study found, the people with cancer consistently performed better on memory tests. In the decade before the cancer diagnosis, their memory declined at a 10.5% slower rate than their counterparts who remained cancer-free.

After the diagnosis, cancer patients did typically see a sudden worsening in their memory for a short time. But afterward, their rate of memory decline continued at the same pace as before the diagnosis — which meant they maintained an advantage over cancer-free older adults.

There are theories as to why the pattern exists: Some of the mechanisms that allow cancer cells to grow and spread may, in the brain, protect cells from dying.

Glymour’s team points to the example of an enzyme called PIN1: Its activity is enhanced in cancer, but decreased in Alzheimer’s. Among other roles, the enzyme is thought to help prevent the buildup of abnormal proteins in the brain that are the hallmark of Alzheimer’s.

But there is a lot of work to do before all the pieces can be put together, according to Glymour. One question is whether only certain cancer types are connected to a lower risk of memory decline and dementia.

In past studies, the link has been surprisingly consistent among different cancers, Glymour noted. “But,” she said, “we think that might just be because there were not enough cases of different types of cancer to detect the differences.”

If larger studies do show that only certain cancers are tied to slower memory decline, Glymour noted, that could give clues about the underlying reasons.

Dr. Olivia Okereke is director of geriatric psychiatry at Massachusetts General Hospital in Boston. She said the association between cancer and a lower risk of Alzheimer’s is puzzling and “sounds counterintuitive” — since cancer, and some cancer treatments, can actually take a toll on mental skills such as attention, information-processing and short-term memory.

“But these associations have been noted in studies for years now,” said Okereke, who wrote an editorial accompanying the research. Both were published June 21 online in JAMA Network Open.

She called the new study a “very useful contribution,” because it shows the memory advantage exists before people ever develop cancer, then persists afterward.

That, Okereke said, suggests that “common underlying mechanisms” might contribute to cancer while protecting brain cells.

“But we need more research to elucidate those mechanisms,” she added.

Source: HealthDay


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Anti-hypertensive Drug Was Associated with a Decreased Dementia Risk

Various clinical trials indicate what effects can be expected from standardized intervention programs on the basis of existing evidence. Little is known about the way in which such programs can be implemented in actual care practice. However, it may be possible to use data from clinical practice to estimate the potential of drug prescriptions to delay or reduce the development of dementia.

The goal of the present study, which will be published in the next issue of Journal of Alzheimer’s Disease, was to investigate the relationship between antihypertensive drug use and dementia in elderly persons followed in general practices in Germany.

“After another setback for the anti-amyloid strategy, dementia prevention is increasingly becoming an area of interest,” explains Dr. Jens Bohlken, MD, PhD, from the Institute of Social Medicine, Occupational Health and Public Health (ISAP) from the Medical Faculty of the University of Leipzig. “In view of this, our most important task is to find existing therapies that are associated with a reduction in dementia risk or at least an extension of the time to dementia onset.”

This study was based on data from the Disease Analyzer database (IQVIA), which compiles drug prescriptions, diagnoses, and basic medical and demographic data obtained directly and in anonymous format from computer systems used in the practices of general practitioners and specialists. This study included patients with documented blood pressure values and an initial diagnosis of all-cause dementia in 739 general practices in Germany between January 2013 and December 2017 (index date). Inclusion criteria were as follows: age 60 years at the index date, observation time of at least 12 months prior to the index date, and hypertension diagnosis prior to the index date. After applying similar inclusion criteria, dementia cases were matched to non-dementia controls using propensity scores based on age, sex, index year, and co-diagnoses (i.e. diabetes mellitus, hyperlipidemia, stroke including transient ischemic attack, coronary heart disease, depression, intracranial injury, Parkinson’s disease, osteoporosis, and epilepsy). For the controls, the index date was that of a randomly selected visit between January 2013 and December 2017.

The main outcome of the study was the incidence of dementia as a function of the use of antihypertensive drugs (i.e. diuretics, beta blockers, calcium channel blockers, angiotensin-converting enzyme [ACE] inhibitors, and angiotensin II receptor blockers).

Three logistic regression models were conducted to study the association between the use of antihypertensive drugs and dementia incidence after adjusting for blood pressure (first model: ever versus never use; second model: 3 versus less than 3 years of therapy; third model: 5 versus less than 5 years of therapy).

The present study included 12,405 patients with dementia and 12,405 patients without dementia (mean age: 80.6 years; 61.3% women). The use of angiotensin II receptor blockers (odds ratios [ORs] ranging from 0.74 to 0.79), ACE inhibitors (ORs ranging from 0.85 to 0.88), calcium channel blockers (ORs ranging from 0.82 to 0.89), and beta blockers (OR=0.88) was associated with a decrease in dementia incidence. In patients treated with calcium channel blockers, increasing the duration of treatment decreased the incidence of dementia.

"Antihypertensive therapy alone cannot guarantee that dementia will never occur," noted corresponding author Prof. Karel Kostev, PhD, from the Epidemiology Department of IQVIA (Germany), "However, these findings highlight the importance of the prescription of antihypertensive drugs in the context of preventing hypertension-associated cognitive decline."

The authors of the study also note that: "further studies are needed to gain a better understanding of the medications associated with a decreased risk of dementia. We plan to investigate the role of lipid-lowering drugs, antidepressants, and further medications in the future."

The study is subject to some limitations, as the patients in the study were 60 or older, and this inclusion criterion was necessary for identifying dementia. However, previous research has shown that it is important for a life course-related prevention strategy to initiate hypertension treatment at a younger age. Moreover, data on patients' lifestyle factors, including smoking and physical activity, education, and job, were also lacking. The strengths of this study are the number of patients available for analysis, which allowed the use of a case-control design, and the use of real-world data, with different diagnoses and medications available for analysis.

Source: Science Daily


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Weight Gain and Loss May Worsen Dementia Risk in Older People

Older people who experience significant weight gain or weight loss could be raising their risk of developing dementia, suggests a study from Korea published today in the online journal BMJ Open.

Dementia is an important health problem especially with increasing life expectancy and an ageing population. In 2015, there were an estimated 46.8 million people diagnosed with dementia.

Meanwhile, the global prevalence of obesity, which is closely related to cardiometabolic diseases, has increased by more than 100% over the past four decades.

There is existing evidence of a possible association between cardiometabolic risk factors (such as high blood pressure, cholesterol and blood sugar levels) and dementia. However, the association between body mass index (BMI) in late-life and dementia risk remains unclear.

Therefore, a team of researchers from the Republic of Korea set out to investigate the association between BMI changes over a two-year period and dementia in an elderly Korean population.

They examined 67,219 participants aged 60-79 years who underwent BMI measurement in 2002-2003 and 2004-2005 as part of the National Health Insurance Service-Health Screening Cohort in the country.

At the start of the study period, characteristics were measured including BMI, socioeconomic status and cardiometabolic risk factors.

The difference between BMI at the start of the study period and at the next health screening (2004-2005) was used to calculate the change in BMI.

After two years, the incidence of dementia was monitored for an average 5.3 years from 2008 to 2013.

During the 5.3 years of follow-up time, the numbers of men and women with dementia totaled 4,887 and 6,685, respectively.

Results showed that there appeared to be a significant association between late-life BMI changes and dementia in both sexes.

Rapid weight change – a 10% or higher increase or decrease in BMI – over a two-year period was associated with a higher risk of dementia compared with a person with a stable BMI.

However, the BMI at the start of the period was not associated with dementia incidence in either sex, with the exception of low body weight in men.

After breaking down the figures based on BMI at the start of the study period, the researchers found a similar association between BMI change and dementia in the normal weight subgroup, but the pattern of this association varied in other BMI ranges.

Cardiometabolic risk factors including pre-existing hypertension, congestive heart failure, diabetes and high fasting blood sugar were significant risk factors for dementia.

In particular, patients with high fasting blood sugar had a 1.6-fold higher risk of developing dementia compared to individuals with normal or pre-high fasting blood sugar.

In addition, unhealthy lifestyle habits such as smoking, frequent drinking and less physical activity in late life were also associated with dementia.

This is an observational study, so can’t establish cause, and the researchers point to some limitations, including uncertainty around the accuracy of the definition of dementia and reliance on people’s self-reported lifestyle habits, which may not be accurate.

However, the study included a large amount of data and reported various modifiable risk factors of dementia in late life.

As such, the researchers conclude: “Both weight gain and weight loss may be significant risk factors associated with dementia. This study revealed that severe weight gain, uncontrolled diabetes, smoking and less physical activity in late-life had a detrimental effect on dementia development.

“Our results suggest that continuous weight control, disease management and the maintenance of a healthy lifestyle are beneficial in the prevention of dementia, even in later life.”

Source: EurekAlert!

Want to Prevent Dementia? Follow these WHO New Guidelines

If you want to save your brain, focus on keeping the rest of your body well with exercise and healthy habits rather than popping vitamin pills, new guidelines for preventing dementia advise. About 50 million people currently have dementia, and Alzheimer’s disease is the most common type.

Each year brings 10 million new cases, says the report released Tuesday by the World Health Organization. Although age is the top risk factor, “dementia is not a natural or inevitable consequence of aging,” it says.

Many health conditions and behaviors affect the odds of developing it, and research suggests that a third of cases are preventable, said Maria Carrillo, chief science officer of the Alzheimer’s Association, which has published similar advice.

Since dementia is currently incurable and so many experimental therapies have failed, focusing on prevention may “give us more benefit in the shorter term,” Carrillo said.

Much of the WHO’s advice is common sense, and echoes what the U.S. National Institute on Aging says.

That includes getting enough exercise; treating other health conditions such as diabetes, high blood pressure and high cholesterol; having an active social life, and avoiding or curbing harmful habits such as smoking, overeating and drinking too much alcohol. Evidence is weak that some of these help preserve thinking skills, but they’re known to aid general health, the WHO says.

Eating well, and possibly following a Mediterranean-style diet, may help prevent dementia, the guidelines say. But they take a firm stance against vitamin B or E pills, fish oil or multi-complex supplements that are promoted for brain health because there’s strong research showing they don’t work.

“There is currently no evidence to show that taking these supplements actually reduces the risk of cognitive decline and dementia, and in fact, we know that in high doses these can be harmful,” said the WHO’s Dr. Neerja Chowdhary.

“People should be looking for these nutrients through food … not through supplements,” Carrillo agreed.

The WHO also did not endorse games and other activities aimed at boosting thinking skills. These can be considered for people with normal capacities or mild impairment, but there’s low to very low evidence of benefit.

There’s not enough evidence to recommend antidepressants to reduce dementia risk although they may be used to treat depression, the report says. Hearing aids also may not reduce dementia risk, but older people should be screened for hearing loss and treated accordingly.
Source: CBS


Read the WHO Guidelines Publication:

RISK REDUCTION OF COGNITIVE DECLINE AND DEMENTIA . . . . .


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New Type of Dementia Identified

“Form of dementia that ‘mimics’ Alzheimer’s symptoms discovered,” reports The Guardian.

An international team of researchers has proposed a name for a type of brain disease that causes dementia symptoms: Limbic-predominant Age-related TDP-43 Encephalopathy, or LATE.

The name brings together previously identified conditions linked to a protein that damages regions of the brain.

The damage causes memory and thinking problems, similar to those seen in Alzheimer’s disease and other types of dementia.

Alzheimer’s disease is thought to be caused by an accumulation of 2 types of protein, tau and amyloid beta, in the brain.

LATE is thought to be caused by another protein, TDP-43, which is usually present in the centre of nerve cells, but may change form and spread into the body of nerve cells as people get older.

It’s thought to affect around 20% of adults over 80. Some people may have both types of disease.

At present LATE can only be diagnosed by examining brain tissues after death.

Researchers say it may explain why some recent trials of treatments for Alzheimer’s disease have been unsuccessful.

They say treatments may have effectively treated the proteins that cause damage in Alzheimer’s disease, but LATE may have continued, masking any improvements to Alzheimer’s symptoms.

They’re calling for research to find markers that allow LATE to be diagnosed before death so clinical studies on its causes and potential treatments can begin.

But understanding of this condition is still in the early stages and as experts say, it’s not something that could be currently diagnosed in the clinic.

Why is this in the news?

A group of researchers working in this area came together to publish a consensus report in the peer-reviewed journal Brain.

It’s open access, so you can read the report for free online.

The researchers come from 22 universities and research institutes in the US, the UK, Sweden, Australia, Austria and Japan.

The consensus report:

  • describes the main features and effects of the disease on the brain
  • sets out proposed diagnostic criteria to diagnose and stage LATE in examination of the brain after death
  • sets out what’s known about the clinical effects of the disease
  • considers the possible effect of the disease on public health, now and in the future
  • sets out priorities for research

The working group members say they want to encourage more research into the disease, and hope that the criteria they propose for diagnosing LATE will help to focus and clarify research in the future.

What kind of research was this?

The consensus statement was based on a review of existing studies about TDP-43 brain diseases, Alzheimer’s disease and reports of dementia symptoms with no signs of Alzheimer’s disease.

The working group discussed the research they found and drew up a statement summarising what they thought previous research shows us, how it should be interpreted, and how the disease should be categorised and researched in future.

What’s the difference between LATE and other types of dementia?

Dementia is a syndrome (a group of related symptoms) associated with an ongoing decline of brain functioning.

There are many types of dementia, including Alzheimer’s disease, vascular dementia, dementia with Lewy bodies, and LATE.

Dementia symptoms can include problems with:

  • memory loss
  • thinking speed
  • mental sharpness and quickness
  • language
  • understanding
  • judgement
  • mood
  • movement
  • difficulties carrying out daily activities

The differences between the types of dementia are in the causes. LATE seems to be caused by damage from one type of protein, while Alzheimer’s disease seems to be caused by other types of protein.

Vascular dementia happens when at some point there’s been a lack of oxygen to areas of the brain, causing damage.

But there may sometimes be overlap in conditions and it’s not always possible to give a single, definite cause of a disease. The results in terms of dementia symptoms may be broadly the same.

LATE is thought to mainly affect older people (aged 80 and over) and becomes more likely year on year, but again many people may not just have this one distinct type.

How does LATE affect you?

At present there’s no way to diagnose LATE while someone is still alive, but only by examining the brain at autopsy.

This is actually very similar to Alzheimer’s disease. While brain scans can indicate likely Alzheimer’s, examination of the brain tissue is needed to be sure of the diagnosis.

Nor is it possible to distinguish LATE from Alzheimer’s disease based on the symptoms.

There are no treatments for LATE. The main purpose of the new name and the consensus document is to guide researchers so they can better understand the disease.

Better understanding of the types of diseases that cause dementia may lead to better diagnosis and treatments. But that’s unlikely to happen for several years yet.

Source : NHS