ROCHESTER, Minn. — A Mayo Clinic study shows heart conditions such as coronary artery disease and cardiovascular risk factors such as diabetes and high cholesterol have stronger association with decline in memory and thinking skills during midlife for women than men. That's despite a higher prevalence of those conditions in men. The research is published in Neurology, the medical journal of the American Academy of Neurology.
"It is well-known that men, compared to women, have a higher prevalence of cardiovascular conditions and risk factors in midlife. However, our study suggests that women in midlife with these conditions and risk factors are at greater risk of cognitive decline," says Michelle Mielke, Ph.D., a Mayo Clinic epidemiologist and neuroscientist, and senior author of the study. "Thus, while all men and women should be treated for cardiovascular conditions and risk factors in midlife, additional monitoring of women may be needed as a potential means of preventing cognitive decline."
The research used the population-based Mayo Clinic Study of Aging and included 1,857 participants without dementia who were 50 to 69 at their initial visit. Of the participants, 920 were men and 937 were women. Every 15 months for an average of three years, study participants' global cognition was evaluated with nine tests of memory, language, executive function and spatial skills.
Cardiovascular condition and risk factor information were obtained using the population-based Rochester Epidemiology Project. Conditions included coronary artery disease, heart rhythm disorders, congestive heart failure, peripheral artery disease and stroke. Risk factors included high blood pressure, diabetes, high cholesterol, smoking and obesity. About 79% of the participants, or 1,465, had at least one cardiovascular risk factor or condition — 83% of men, compared to 75% of women.
The study found most cardiovascular conditions were more strongly associated with cognitive function among women. The annual decline for global cognition associated with coronary artery disease, for example, was more than two times greater for women than men.
In addition, diabetes, high cholesterol and coronary artery disease were associated with greater language decline in women. However, congestive heart failure was associated with greater language decline in men.
It is important to understand sex differences in the development of cognitive impairment to enhance the health of women and men, Dr. Mielke says. Middle-aged adults, especially women with a history of heart disease, may represent critical subgroups for early monitoring. Additional research is needed across the life span to examine potential mechanisms explaining sex differences in the relationship between cardiovascular factors and cognition, such as hormones, genetics, lifestyle and psychosocial factors, Dr. Mielke says.
Funding for this study was provided by grants from the National Institutes of Health and the GHR Foundation, and resources were provided by the Rochester Epidemiology Project, which is supported by the National Institute on Aging.
Other study authors are Nan Huo, M.D., Ph.D.; Prashanthi Vemuri, Ph.D.; Jonathan Graff-Radford, M.D.; Jeremy Syrjanen; Mary Machulda, Ph.D.; David Knopman, M.D.; Clifford Jack Jr., M.D.; and Ronald Petersen, M.D., Ph.D. — all of Mayo Clinic.
Dr. Mielke is a consultant for Biogen and Brain Protection Co., and she is on the editorial boards of Neurology and the Alzheimer's & Dementia Journal.