Sex Differences in the Association between Metabolic Dysregulation and Cognitive Aging: The Health and Retirement Study.

Abstract

BACKGROUND\nDysregulation of some metabolic factors increases the risk of dementia. It remains unclear if overall metabolic dysregulation, or only certain components, contribute to cognitive aging and if these associations are sex-specific.\n\n\nMETHODS\nData from the 2006-2016 waves of the Health and Retirement Study (HRS) was used to analyze 7,103 participants aged 65+ at baseline (58% women). We created a metabolic-dysregulation risk score (MDRS) composed of blood pressure/hypertension status, HbA1c/diabetes status, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and waist circumference, and assessed cognitive trajectories from repeated measures of the HRS-Telephone Interview for Cognitive Status (HRS-TICS) over 10 years of follow-up. Linear mixed-effects models estimated associations between MDRS or individual metabolic factors (biomarkers) with mean and change in HRS-TICS scores and assessed sex-modification of these associations.\n\n\nRESULTS\nParticipants with higher MDRSs had lower mean HRS-TICS scores, but there were no statistically significant differences in rate of decline. Sex-stratification showed this association was present for women only. MDRS biomarkers revealed heterogeneity in the strength and direction of associations with HRS-TICS. Lower HRS-TICS levels were associated with hypertension, higher HbA1c/diabetes, and lower HDL-C and TC; while faster rate of cognitive decline was associated with hypertension, higher HbA1c/diabetes and higher TC. Participants with higher HbA1c/diabetes presented worse cognitive trajectories. Sex-differences indicated women with higher HbA1c/diabetes to have lower HRS-TICS levels while hypertensive males presented better cognitive trajectory.\n\n\nCONCLUSIONS\nOur results demonstrate that metabolic dysregulation is more strongly associated with cognition in women compared to men, though sex-differences vary by individual biomarker.