AAIC 2014: Alzheimer’s risk factors in sharper relief

A number of factors are standing out as promoters for and protectors against the development of Alzheimer’s disease, according to research presented during the 2014 Alzheimer’s Association International Conference (AAIC) being held July 12-17 at the Bella Center in Copenhagen, Denmark.

The data not only provides a distinct picture of risk for vulnerable populations, but it also breaks information out into specific demographics. For example, the research indicated that veterans are at increased risk of developing Alzheimer’s if they have sleep problems. This is exacerbated further if they suffer from post-traumatic stress disorder (PTSD). The retrospective study, conducted at the University of California, San Francisco, included data from some 200,000 veterans. After tracking eight year’s worth of records, researchers found that non-specific sleep disturbance, sleep apnea and insomnia at the beginning of the study were associated with a 30 percent increased risk of developing dementia. Add PTSD to the mix and the risk jumped to 80 percent.

Surprisingly, for patients older than 90, high blood pressure may have a protective effect against developing dementia. This is in stark contrast to what is generally thought about hypertension and dementia risk. This research was conducted at the University of California, Irvine, and assessed the connection between risk of dementia, onset of hypertension and blood pressure parameters for 625 patients in the latest stage of life. Researchers tracked patients for as long as 10 years at intervals of six months. Results of this study showed that blood pressure in the hypertensive range had a significantly reduced risk of dementia compared to those with normal levels of blood pressure. The link was the same whether or not patients were taking blood pressure medications.

“Determining more specifically the factors that raise and lower risk of Alzheimer’s disease and other dementias is an essential component in our battle against the Alzheimer’s epidemic,” said Heather Snyder, PhD, director of medical and scientific operations for the Alzheimer’s Association, according to a press release. “We are now getting a more clear idea of the opportunities for risk reduction through behavior changes and other health factors. We’re learning that Alzheimer’s risk and protective factors may change over the course of our lives.”

In other data, growing evidence has proven that regular physical activity and mental engagement protect against dementia in the later stages of life and may even improve brain volumes. Scientists are not yet certain what specific mechanisms are behind these safeguards.

The data on mental engagement, such as games and puzzles, was based on research conducted at the Wisconsin Alzheimer’s Institute and the Wisconsin Alzheimer’s Disease Research Center. In this study, 329 cognitively normal middle-aged adults underwent MRI imaging and cognitive tests. Of these subjects, 74 percent of people had Alzheimer’s in their family’s history and 40 percent of participants tested positive for the APOe4 gene.

For the data on physical activity, a Mayo Clinic study reviewed 1,830 cognitively normal patients and assessed the link between exercise and risk of developing MCI. This research resulted in reduced risk of developing MCI for light, moderate and vigorous exercise in middle age as well as those who are older.

In a separate study conducted at the Mayo Clinic, researchers elucidated the link between time of exercise and risk of new dementia diagnosis for 280 adults with mild cognitive impairment (MCI) and a median age of 81 from the Mayo Clinic Study of Aging. Researchers tracked patients for about three years. Results of this study showed that moderate exercise in middle age had the most impact in reducing progression to dementia. However the link was not significant for light or vigorous exercise in middle age and no category of exercise made a strong impact in protecting patients with MCI from progressing to dementia later than middle age. 

“These studies from AAIC 2014 underscore the need to fund larger, longer-term studies in different and diverse populations to enable us to develop helpful ‘prescriptions’ for lifestyle change – for example, which foods to eat and avoid, how much physical activity and what types – and to learn more specifically about how Alzheimer’s and dementia risk factors change as we age,” said Snyder.