Groundbreaking research suggests that cognitive decline caused by a range of cardiovascular conditions may be worse in women than men.
The study, pioneered by experts at the American Academy of Neurology (AAN), provides unprecedented insight into the effects of cardiovascular health on cognitive decline in women, potentially helping to devise life-changing interventions.
The research, which is published in Neurology, was supported by the National Institutes of Health, the GHR Foundation and the Rochester Epidemiology Project.
Despite men being more likely to develop cardiovascular conditions such as heart disease and stroke, and risk factors like diabetes, high blood pressure and smoking in middle age than women, the detrimental effects of these conditions on memory and thinking are possibly stronger in women.
Leader of the research, Michelle M. Mielke, PhD, of the Mayo Clinic in Rochester and a member of the American Academy of Neurology, commented: “Our results show that midlife cardiovascular conditions and risk factors were associated with midlife cognitive decline, but the association is stronger for women.
“Specifically, we found that certain cardiovascular conditions, such as diabetes, heart disease and dyslipidaemia, which is abnormally high levels of fats in the blood, had stronger associations with cognitive decline in women compared to men.”
Dissecting cognitive decline in women
For their study, the team examined 1,857 individuals without dementia who were aged between 50 and 69 years at the study’s inception. The participants underwent a clinical evaluation every 15 months for an average of three years, which included nine tests of memory, language, executive function, and spatial skills, enabling them to calculate a composite cognitive score.
Of the participants, 1,465 (79%) had at least one cardiovascular risk factor, and more men than women had at least one risk factor, 83% for men and 75% for women. The team identified that the most cardiovascular conditions were more strongly associated with cognitive function among women. For example, heart disease was associated with more than a two-fold greater decline in cognitive test scores for women compared to men.
Furthermore, the researchers identified that heart disease, diabetes, and abnormally higher fat levels in the blood were only associated with language score decline in women. Contrastingly, congestive heart failure was only associated with language score decline in men.
Mielke said: “More research is needed to examine sex differences in the relationships between the cardiovascular risk factors and specific biomarkers of brain disease like white matter hyperintensities, areas of dead tissue and overall white matter integrity in midlife.
“That may help us better understand the sex-specific mechanisms, by which the cardiovascular conditions and risk factors contribute to cognitive impairment in both women and men.”
The researchers noted that a limitation of the study is that participants were all from one county in Minnesota, meaning the results cannot be generalised to other populations. Furthermore, it does not demonstrate that women with cardiovascular risk factors will have a cognitive decline in midlife but suggests an association.