Cognitive Impairment Among Older Americans Decreasing

A recent study shows a downward trend in the rate of cognitive impairment among people aged 70 and older. The study was led by two University of Michigan Medical School physicians and their colleagues, and is based on data from the Health and Retirement Study (HRS), a national survey of older Americans funded by the National Institute on Aging and based at the U-M Institute for Social Research (ISR).

"From these results, we can say that brain health among older Americans seems to have improved in the decade studied, and that education and wealth may be a big piece of the puzzle," says lead author Kenneth Langa, M.D., Ph., an associate professor of internal medicine who also holds appointments in ISR and the VA Ann Arbor Healthcare System.

Between 1993 and 2002 the incidence of cognitive impairment in this age group decreased by 3.5%, or hundreds of thousands of people. The reasons for this decline are not yet known, but the authors of the survey state that older people today have had more formal education, higher economic status and better care for risk factors—high blood pressure, high cholesterol, and smoking – that can endanger their brains. Of the 11,000 people in the study, those with more formal education and personal wealth were less likely to have cognitive problems.

The study was publishe in the the online edition of the journal Alzheimer’s and Dementia.

Source: Alzheimer’s & Dementia, Feb 18, 2008, online edition.

Study Suggests Folate Deficiency Increases Dementia Risk Three-Fold

Recent research suggests that the risk of dementia in elderly people is increased three times by a lack of folate.

518 people were monitored for the development of dementia during the years 2001 through 2003. All subjects were aged 65 and over and lived in either a rural or urban community in the southern part of the country. Tests were carried out at the beginning and end of the 2-year period to check for any dementing illnesses. Blood tests were also conducted to measure levels of folate, vitamin B12, and the protein homocysteine, and how these changed over time. High levels of homocysteine have been associated with cardiovascular disease.

At the beginning of 2001, almost 20% of people monitored hd high levels of homocysteine, 3.5% were folate deficient, and 17% had low vitamin B12 levels.The higher the beginning levels of folate, the higher were vitamin B12 levels, and the lower were those of homocysteine.

By the end of 2003, 45 people had developed dementia, and of these 34 had Alzheimer’s disease, 7 had vascular dementia and 4 had other types of dementia. It was observed that dementia was more probable in the older, poorly educated and inactive subjects, and among those who had deposits of th protein ApoE.

People whose folate levels fell during the 2-year period were significantly more likely to develop dementia, while their homocysteine levels rose. People who were folate deficient to begin with, were almost 3.5 times more likely to develop dementia.

The research was published in the Journal of Neurology Neurosurgery and Psychiatry.

Source: J Neurol Neurosurg Psychiatry 2008; doi 10.1136/jnnp.2007.131482

Elevated Blood Pressure May Result in Mild Cognitive Impairment

A report in the December, 2007 issue of Archives of Neurology claims that high blood pressure can increase the risk of mild cognitive impairment, affecting the ability to thinking and learning.

About 9.9 of every 1000 elderly people who do not have dementia develop mild cognitive impairment early, and of these, 10%-12% develop Alzheimer’s disease. compared with 1%-2% of the general population. Dr. Christiane Reitz, M.D., Ph.D., and colleagues at the Columbia University Medical Center, New York, monitored 918 Medicare patients with an average age of 76.3 years, starting in 1992 through 1994. None had any mild cognitive impairment. Participants were then checked every 18 months, for an average of 4.7 years. People with mild cognitive impairment registered low cognitive scores and a defective memory, but were not diagnosed with dementia.

334 people developed mild cognitive impairment during the follow-up phase— including 160 cases of amnestic mild cognitive impairment, and 174 cases of non-amnestic mild cognitive impairment. High Blood pressure was connected with an increased risk of all types of mild cognitive impairment that was mostly associated with an increased risk of non-amnestic mild cognitive impairment. Hypertension was not associated with amnestic mild cognitive impairment, or a change in memory and language

"The mechanisms by which blood pressure affects the risk of cognitive impairment or dementia remain unclear," the authors write. "Hypertension may cause cognitive impairment through cerebrovascular disease. Hypertension is a risk factor for subcortical white matter lesions found commonly in Alzheimer’s disease. Hypertension may also contribute to a blood-brain barrier dysfunction, which has been suggested to be involved in the cause of Alzheimer’s disease. Other possible explanations for the association are shared risk factors," including the formation of cell-damaging compounds known as free radicals.

The authors believe that their findings support the hypothesis that hypertension increases the risk of incident mild cognitive impairment, especially non-amnestic mild cognitive impairment They conclude that preventing and treating hypertension may be important in lowering the risk of cognitive impairment.

Source: American Medical Association (AMA)

One in Seven Americans Over 70 Has Dementia

A new analysis suggests that about 3.4 million Americans over 70 years of age—one in seven people in that age group—has dementia, and 2.4 million of them have Alzheimer’s disease (AD).

The study was published online this week in Neuroepidemiology, and is the first to estimate rates of dementia and AD using a nationally representative sample of older adults across the United States.

The study highlights the nationwide reach of dementia, which affects not only those with the disease, but their families and communities as well. "As the population ages during the next few decades, the prevalence of Alzheimer’s disease will increase several-fold unless effective interventions are discovered and implemented," said National Institute on Aging Director Richard J. Hodes, M.D. "These data underscore the urgency of research in this area."

The study included 856 HRS participants over the age of 70 from 42 states in 2001-2003. Aging, Demographics and Memory Study (ADAMS) interviewers from Duke University Medical School conducted at-home evaluations to gather information about each participant’s cognitive and functional status and symptoms, neuropsychiatric symptoms, current medications, medical history and family history of memory problems. Prior neuroimaging and laboratory results were also obtained.

A team of clinicians reviewed the evaluation information and made a preliminary assessment of each person’s cognitive status. A consensus panel of other medical experts then used well-accepted diagnostic criteria to determine if the participant had normal cognitive function, cognitive impairment without dementia, or dementia. Such criteria further were used to discern the type of dementia, including AD or vascular dementia, the second most common cause of dementia in older adults.

Based on the experts’ classifications, Drs. Plassman and Langa and co-authors estimated the national prevalence and total numbers of people age 71 and older, by age group, with any dementia and with AD or vascular dementia in 2002. According to their calculations, 13.9 percent of Americans age 71 and older have some type of dementia, 9.7 percent of Americans in that age group have AD, and 2.4 percent have vascular dementia. AD accounted for about 70 percent of all dementia cases among people 71 and older.

As in other studies, the ADAMS analysis showed that the prevalence of dementia increases significantly with age. Five percent of people ages 71 to 79, 24.2 percent of people 80 to 89, and 37.4 percent of those 90 years or older were estimated to have some type of dementia. The estimated rate of Alzheimer’s also rose greatly with older age — from 2.3 percent of people ages 71 to 79 to 18.1 percent of people 80 to 89 to 29.7 percent of those age 90 and older. The ADAMS investigators found fewer years of education and the presence of at least one APOE e4 allele, a genetic risk factor for AD, to be strong predictors of AD and other dementias.

Richard Suzman, Ph.D., director of NIA’s Behavioral and Social Research Program, which jointly directs the HRS, said the ADAMS data will prove particularly valuable not only in assessing the prevalence of dementia, but also its impact. "ADAMS, with its link to the data about the health, economic, and family resources of individuals in the study, will help us to characterize more fully the burden of dementia on individuals, caregivers and the nation’s health care system," he says.

The ADAMS report is the latest published study to estimate the prevalence of dementia and AD among older Americans. "These assessments have provided a range of estimates, based on differing methodologies and approaches," explains Dallas Anderson, Ph.D., program director for population studies in NIA’s Dementias of Aging Branch.

For example, some studies have included lower age ranges than ADAMS or broader characterizations of dementia, or have sampled participants in a specific community as a base for national extrapolations. A study reported in 1998 (Brookmeyer et al., 1998) combined incidence data from four community-based studies, estimating that national Alzheimer’s prevalence among individuals age 60 years or older would rise from 2.3 million in 1997 to 8.6 million in 2047. Widely cited estimates based on the prevalence of Alzheimer’s disease in a Chicago-based community (Hebert et al., 2003), and an earlier comparable study using data from East Boston (Evans et al., 1990) forecast the number of those age 65 or older with AD to be 5.1 million in 2010.

Despite the varied approaches and findings, however, NIA experts point out, the numbers of people with dementia, and Alzheimer’s specifically, will certainly increase until ways to delay the progression or prevent the dementia are found. Advancing age is the most common known risk factor for Alzheimer’s disease.

The HRS is an ongoing national survey of 22,000 adults age 51 and older that began in 1992, providing data that helps researchers, policy makers and others understand the life circumstances of older adults and help address the challenges of the nation’s rapidly aging population.

NIA leads the federal effort supporting and conducting research on aging and the medical, social and behavioral issues of older people, including AD and age-related cognitive change.

The National Institutes of Health (NIH) — The Nation’s Medical Research Agency — includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases.

Brenda L. Plassman, Ph.D., of Duke University Medical Center, with Kenneth M. Langa, M.D., Ph.D., and David R. Weir, Ph.D., of the University of Michigan, Robert B. Wallace, Ph.D., of the University of Iowa, and others, conducted the analysis as part of the Aging, Demographics and Memory Study (ADAMS). ADAMS is a sub-study of the larger Health and Retirement Study (HRS), the leading resource for data on the combined health and economic circumstances of Americans over age 50. ADAMS and the HRS are sponsored by the National Institute on Aging, a component of NIH, under a cooperative agreement with the University of Michigan.

Source: National Institutes of Health, October 30, 2007

Some Hypertension Drugs May Also Treat Alzheimer’s

Recent research points to the possibility that patients being treated with hypertension drugs may also benefit from the drug’s ability to treat or even prevent Alzheimer’s disease.

"If we can deliver certain anti-hypertensive drugs to patients at high risk to develop Alzheimer’s disease, at doses that do not affect blood pressure, these drugs could be made available for all members of the geriatric population identified as being at high
risk for developing Alzheimer’s disease", says Dr. Giulio Maria Pasinetti of Mount Sinai School of Medicine.

Under Dr. Pasinetti’s supervision, more than 1,500 drugs used to treat other disorders have been screened for their potential in treating Alzheimer’s disease, and 7 out of 55 drugs prescribed for the treatment of hypertension have been identified as significantly preventing beta-amyloid production, which plays a key role in Alzheimer’s disease pathogenesis.

Valsartan, an anti-hypertensive agent, was found to pharmacologically prevent beta-amyloid production in the brains of test mice even when administered to Alzheimer’s disease mice at 3-4 times lower than the minimal equivalent dose prescribed for the treatment of hypertension in humans.

Other hypertension drugs with positive results included Propranol HCI, Carvedilol, Losartan, Nicardipine HCI, Amiloride HCI and Hydralazine HCI.

"The use of these drugs for their potential anti-Alzheimer’s disease role is still highly experimental," said Dr. Pasinetti, "and at this stage we have no clinical data beyond phenomenological observation in humans. We need to complete preventive and therapeutic clinical trials in the near future if we are to identify certain anti-hypertensive drugs with anti beta-amyloid antiligomeric activities, which will need to be prescribed at dosages that do not interfere with blood pressure in normotensive Alzheimer’s patients."

The research was conducted by Dr.Giulio Maria Pasinetti, MD, Ph.D., Professor of Psychiatry and Neuroscience, Geriatrics and Adult Development , and Director of the Center of Excellence for Research in Complementary and Alternative Medicine in Alzheimer’s Disease at Mount Sinai School of Medicine, and published in the November, 2007 issue of the The Journal of Clinical Investigation.

Rate of Memory Loss Greater in Dementia Patients With More Education

According to a recent study in the journal Neurology, while higher education levels initially delay the onset of dementia, once dementia starts, the rate of memory loss is more rapid than in less educated individuals.

According to study author Charles B. Hall, PhD of the Albert Einstein College of Medicine, "our study showed that a person with 16 years of formal education would experience a rate of memory decline that is 50% faster than someone with just four years of education."

The study started in the 1980s, and monitored 488 people born between 1894 and 1906, with study findings based on the 117 members of the sample who eventually developed Alzheimer’s or some other form of dementia. Study participants ranged from people with postgraduate education to people with less than three years of elementary school education.

Dr. Hall believes that this rapid decline in the more educated people might be explained by their having a greater cognitive reserve, or the brain’s ability to maintain function in spite of damage. This meant that while patients are often diagnosed with dementia at a later date, once the cognitive reserve is no longer able to compensate for the damage that has occurred, then the symptoms emerge.

The study is valuable, says Dr. Hall, because it examines memory loss before a formal diagnosis of Alzheimer’s.

The study was supported by the National Institute on Aging. Other researchers from the Einstein Aging Study involved in the research included Carol Derby, PhD; Aaron LeValley, MA; Mindy J. Katz, MPH; Joe Verghese, MD; and Richard B. Lipton, MD.

Source: Neurology, October 23, 2007

Conscientiousness May Help Protect Against Alzheimer’s Disease

Results of a recent study about the link between conscientiousness and Alzheimer’s disease may provide yet another strategy for delaying the symptoms of Alzheimer’s, according to a study published in the October issue of Archives of General Psychiatry.


Conscientiousness, which generally refers to a person’s ability to be goal-directed and control impulses, has been associated with various mental and physical disorders. In the published study, which ran from 1994 to 2006 and studied nearly 1,000 older individuals, participants were evaluated for medical history, neurologic examinations and cognitive testing.

The "conscientiousness score" was determined with a 12-items evaluation where participants rated their agreement with a number of statements, such as: “I am a productive person who always gets the job done." Those who had conscientiousness scores in the top 10% had an 89% lower risk of developing Alzheimer’s disease than those whose scores ranked in the bottom 10% of the conscientiousness score.

The study’s author’s posit that conscientious people are more likely to be succesful in education and work, both of which have been associated with a reduced risk of Alzheimer’s disease. In addition, conscientiousness has been linked to resilience and to coping actively with difficulties. “These factors might lessen the adverse consequences of negative life events and chronic psychological distress, which have been associated with risk of dementia in old age,” the researchers note.

The study concludes that the "level of conscientiousness is associated with incidence of mild cognitive impairment and Alzheimer’s disease but not with the pathologic hallmarks of these conditions."

 

Source: Arch Gen Psychiatry. 2007;64(10):1204-1212.

Alzheimer’s and Aluminum

Aluminum is unusually abundant in the neurofibrillary tangles of Alzheimer’s disease. For years, rumors have circulated that aluminum cookware contributed to the disease. And for just as long, most scientists have scoffed at this notion because aluminum is one of the most abundant elements on earth and everyone is exposed to a great deal of it.

Over the last decade several studies have explored the issue of aluminum–especially Aluminum in drinking water–and Alzheimer’s risk. Some show that as the aluminum concentration in water increases beyond about 11 micrograms per liter, so does Alzheimer’s risk. Others show no association.

Studies showing an aluminum-Alzheimer’s link suggest that aluminum alone is not the sole culprit. Other substances, notably acids, must be present in the water to enable aluminum absorption in the gut.

Scientists who suspect that aluminum exposure may be a risk factor for Alzheimer’s warn against drinking carbonated beverages from aluminum cans. The carbonation makes the drink acidic, which increases aluminumn absorption in the gut.

The issue of aluminumn as a possible risk factor for Alzheimer’s is extremely controversial.

If you’re concerned enough about aluminum to spend about $100 to have your water tested, the National Testing Laboratory of Cleveland includes aluminum in a 74-item test of water quality.

They send you sampling test tubes. You fill them with your water, and send then to the lab in a special styrofoam-lined box. A week or so later, the lab sends you a report detailing what’s in your water. For more information, call 1-800-458-3330.

— By Matthew Naythons MD and Michael Castleman

Coffee drinking may help thinking skills as women age

According to a study published in the journal Neurology, active coffee drinkers over the age of 65 (who drank at least three cups of coffee a day) had demonstrably less decrease in memory functioning than women who drank only a single cup.

The study surveyed 7,000 women over a period of four years. Surprisingly, the effects of the caffeine increased as the women aged, with 30% less likely to suffer memory decline at 65, rising to 70% at age 80.

The study only looked at memory functioning, not at dementia, with the rates of dementia (Alzheimer’s) constant and unaffected by caffeine intake in the study.

Donepezil Shows Promise for Severe Alzheimer’s

In a study released last week published in the Journal of the American Academy of Neurology, the drug donepezil has improved the cognitive functioning and memory of individuals with severe Alzheimer’s disease.

 
The study, funded by Eisai Inc. and Pfizer, makers of the drug, took place over six months and studied 343 individuals.Half of the group took donepezil and the other half received a placebo.

The results showed that over 63% of the individuals demonstrated memory stabilization or increased function, compared to 39% on the placebo.