The onset of Alzheimer’s disease: the importance of family history

News Release
February 26, 2018 | QUEBEC – The onset of Alzheimer’s disease: the importance of family history

You’re about to turn 60, and you’re fretting. Your mother has had Alzheimer’s disease since the age of 65. At what age will the disease strike you? A Canadian study published in JAMA Neurology shows that the closer a person gets to the age at which their parent exhibited the first signs of Alzheimer’s, the more likely they are to have amyloid plaques, the cause of the cognitive decline associated with the disease, in their brain.

In this study involving a cohort of 101 individuals, researcher Sylvia Villeneuve (Douglas Mental Health University Institute; CIUSSS de l’Ouest-de-l’Île-de-Montréal) shows that the difference between a person’s age and the age of their parent at the onset of the disease is a more important risk factor than their actual age.

A 60-year-old whose mother developed Alzheimer’s at age 63 would be more likely to have amyloid plaques in their brain than a 70-year-old whose mother developed the disease at age 85,” explains Villeneuve, an assistant professor at McGill University and a core faculty member at The Neuro’s McConnell Brain Imaging Centre.

Her team of scientists also found that the genetic impact of Alzheimer’s disease is much greater than previously thought.

“Upon examining changes in the amyloid biomarker in the cerebrospinal fluid samples from our subjects, we noticed that this link between parental age and amyloid deposits is stronger in women than in men. The link is also stronger in carriers of the ApoE4 gene, the so-called ‘Alzheimer’s gene’,” says Villeneuve.

Towards earlier detection of the disease

The researcher and her team successfully duplicated their results in two independent groups, one, consisting of 128 individuals from a University of Washington-St. Louis cohort, the other consisting of 135 individuals from a University of Wisconsin-Madison cohort. They also reproduced their results using an imaging technique that enables one to see amyloid plaques directly in the brains of living persons.

Their study is paving the way for the development of inexpensive methods for the early identification of people at risk for Alzheimer’s disease. According to the Alzheimer Society of Canada, 564,000 Canadians currently have Alzheimer’s disease or another form of dementia. The figure will be 937,000 within 15 years. Presently, there is no truly effective treatment for this disease.

This research was funded by grants from a Canadian research chair, the Canadian Institutes of Health Research, the Canadian Foundation for Innovation, the Canadian Brain Research Fund, the Alzheimer Society of Canada, and the Fonds de recherche du Québec — Santé.

The article entitled “Proximity to parental symptom onset and amyloid burden in sporadic Alzheimer’s disease” was published in JAMA Neurology on February 26, 2018. DOI:10.1001/jamaneurol.2017.5135

Source: http://www.douglas.qc.ca/?locale=en

Older Adults Are Still Likely Underestimating Cognitive Impairment in Their Families

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News release

 Study Finds Racial Differences in Reporting and Overall Trend of Underreporting Cognitive Impairment

An increasing number of older adults are reporting cognitive impairment in their families over the past two decades, according to a new study led by researchers at NYU Rory Meyers College of Nursing and East Carolina University’s Brody School of Medicine.

The study, which also finds ethnic and racial differences in reporting cognitive impairment, is published in Preventing Chronic Disease, a journal of the Centers for Disease Control and Prevention.

The aging population in the U.S. is growing rapidly, with the number of people age 65 and over in 2010 (40.2 million) projected to more than double by 2050. With the rapid increase in the aging population, the size of the population with cognitive impairment and dementia will continue to accelerate, highlighting the importance of identifying cognitive changes.

“Cognitive impairment may serve as a precursor to future dementia. Early detection of cognitive impairment can facilitate timely medical treatments, appropriate care planning, and prevention efforts,” said Bei Wu, PhD, Dean’s Professor in Global Health and director of Global Health & Aging Research at NYU Meyers, co-director of NYU Aging Incubator, and the study’s senior author.

The study sought to examine the trends of self-reported cognitive impairment among five major racial/ethnic groups from 1997 to 2015 in the United States. The researchers used data from the National Health Interview Survey, including 155,682 individuals age 60 and above in their sample. The large sample included people of a variety of races and ethnicities, including Asian Americans,  Blacks, Hispanics, Native Americans, non-Hispanic Blacks, and non-Hispanic Whites.

Rather than using a screening test or clinical examination to evaluate cognitive impairment, respondents were asked to report if any family member was “limited in anyway because of difficulty remembering or because of experiencing periods of confusion.”

The researchers found an increasing trend in self-reported cognitive impairment: the overall rate increased from 5.7 percent in 1997 to 6.7 percent in 2015 among older adults in the U.S. This finding may suggest that awareness of cognitive impairment, perhaps from heightened public attention to and interest in Alzheimer’s disease, has improved to some extent.

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When looking at each racial/ethnic group, however, the increasing trend was significant only among White respondents. In Whites, the rate of self-reported cognitive impairment increased from 5.2 percent in 1997 to 6.1 percent in 2015. Asian American, Black, Hispanic, and Native American respondents had higher rates of self-reported cognitive impairment than Whites, but these rates did not significantly increase from 1997 to 2015.

Regardless of the overall increasing trend, the rates of self-reported cognitive impairment were still low, which may suggest underreporting. The researchers note that the rates of self-reported cognitive impairment are much lower than the estimated prevalence of cognitive impairment. For adults 65 years and older, the rate of self-reported cognitive impairment was 6.3 percent in 2000 and 7.5 percent in 2012, while the estimated prevalence of cognitive impairment in the same age group was 21.2 percent in 2000 and 18.8 percent in 2012.

These findings underscore the need to further promote awareness of cognitive impairment, especially in minority populations. Different cultures hold different beliefs and perceptions of disease and aging. For instance, research has found that compared to Whites, minorities are less likely to seek treatment for psychiatric symptoms because of lack of access to care or due to stigma.

“Culturally specific health education is needed in individuals, family members, and healthcare providers to improve awareness and knowledge of signs and early symptoms of Alzheimer’s and other dementia,” said Huabin Luo, PhD, of East Carolina University.

In addition to Wu and Luo, Gary Yu of NYU Meyers coauthored the study.