The effects of cardiometabolic risk factors on cortical thickness are different between men and women, as women with these risk factors are more vulnerable to cortical atrophy than men, according to study results published in Neurology.
Previous studies have reported that cardiometabolic risk factors such as hypertension, diabetes, and obesity are the major environmental risk factors for dementia and may be related to cortical atrophy. Neuroimaging studies have claimed that aging primarily affects cortical thickness in cognitively normal individuals. The goal of the current study was to assess the impact of cardiometabolic risk factors on cortical thickness according to gender.
The cross-sectional study included men and women ≥65 years of age treated at the Health Promotion Center of the Samsung Medical Central, Seoul, Korea. Screening of 1322 subjects (58.5% men) included assessment of cognitive function, as well as high-resolution 3.0T magnetic resonance imaging. The association between cardiometabolic risk factors and cortical thickness was analyzed following adjustment for possible confounders and interactions with age.
In multivariate analysis among women, hypertension was associated with lower cortical thickness globally (β, -0.024, P =.011) and regionally (frontal β, -0.030, P =.004; temporal β, -1.119, P <.001). Diabetes was also associated with lower cortical thickness in the temporal regions (β, -0.920, P =.030). Furthermore, interaction effect between obesity (body mass index ≥27.5 kg/m2) and age on cortical thickness throughout the entire cortex in women was evident (β, -0.324 to -0.010, P <.05) suggesting that age-related differences in cortical thickness are more prominent by aging in obese women compared with women of normal weight. Low education level, defined as having <6 years of elementary schooling, was also associated with lower cortical thickness throughout the entire cortex (β, -1.019 to -0.059, P <.05).
Among men, being underweight (body mass index ≤18.5 kg/m2) was associated with lower cortical thickness throughout the entire cortex (β, −2.943 to −0.086, P <.05). However, hypertension, diabetes, and low education were not related to lower cortical thickness.
The researchers acknowledged several study limitations, including the cross-sectional design, restricting cohorts to individuals >65 years of age, and missing information regarding duration of exposure to cardiometabolic risk factors.
“The results of our present study highlight the importance of sex-specific relationship of cardiometabolic risk factors with brain aging,” concluded the researchers. They also note that, “These results further suggest that a different approach is needed to prevent and manage dementia in terms of sex differences.”
Kim SE, Lee JS, Woo S, et al. Sex-specific relationship of cardiometabolic syndrome with lower cortical thickness [published online August 23, 2019]. Neurology. doi:10.1212/WNL.0000000000008084.