“The percentage of people with cognitive impairment may actually be going down in the U.S.,” explained Kenneth Langa, MD, PhD, a professor of Medicine at the University of Michigan, as he gave the second Institute on Aging Visiting Scholars lecture of the year last week, here at Penn.
Dr. Langa, a primary investigator on the powerful Health and Retirement Study, was describing data comparing rates of cognitive impairment between 1993 and 2002. As wealth and years of education rose between the 1993 and 2002 cohorts, there was a decrease seen in dementia. In that same time frame, cardiovascular disease, diabetes, and obesity rates went up.
The team also compared brain health in America with a similarly-designed British analysis, finding that Americans’ cognitive health, on the whole, was significantly better than the Brits. Dr. Langa suggested that the earlier push to treat hypertension in America and the greater number of people being treated for hypertension in the U.S. may be associated with better cognitive function in the states, despite our higher rates of cardiovascular disease, obesity and diabetes. Future studies will look at whether this pattern, and the gap in brain health levels, have changed as the level of cardiac care equals out.
When comparing the economic costs of caregiving among different groups, the research showed that caregiving costs for dementia are highest (29%), more than depression (15%), stroke (10%), diabetes (10%), and cancer (2%).
The Health and Retirement Study, started in 1992, has collected health and social science data from 24,000 Americans over the age of 50. From a research perspective, the carefully collected publicly-available data has been a powerful tool for scientists, producing nearly 2000 publications by 1000 authors. The group, led out of the University of Michigan, is now looking at how major medical events, such as severe sepsis, hip fracture, or cardiac bypass, can increase cognitive impairment.