Angoff R, Himali JJ, Ramachandran VS, Seshadri S, Beiser A, Tsao CW (2019) Circulation Nov 2019; 140:A14734
Introduction: The relations of metabolic health and obesity with brain health, particularly in young to middle-aged adults, are not well defined.
Hypothesis: Greater metabolic risk factors and obesity are associated with subclinical brain aging measured by brain MRI and cognitive testing.
Methods: Framingham Heart Study (FHS) 3rd Generation Cohort members (n= 2170, 46±9 years of age, 54% women) without prevalent diabetes, stroke, dementia, or other confounding neurologic conditions were divided into 4 groups based on metabolic health and obesity: metabolically healthy non-obese (MHNO); metabolically healthy obese (MHO); metabolically unhealthy non-obese (MUNO); metabolically unhealthy obese (MUO). Metabolic unhealthiness was defined by ≥2 criteria for metabolic syndrome; obesity was defined as BMI≥30 kg/m2. We evaluated the relations of these groups with brain MRI and neurocognitive tests in multivariable-adjusted models.
Results: MUNO and MUO groups were slightly older (mean 51 years) with a higher prevalence of men, hypertension, and dyslipidemia. Compared to MHNO, both metabolically unhealthy groups (MUNO and MUO) had lower total cerebral brain volume (both p<0.05), TABLE. The MUO group had greater white matter hyperintensity volume (WMHV) (p=0.004), whereas no association between WMHV and either metabolic health or obesity alone was noted. Compared to MHNO, obese individuals had less favorable cognitive scores: MHO had lower scores on global cognition, logical memory-delayed recall and similarities tests, and MUO had lower scores on similarities and visual reproductions-delayed tests (all p≤0.04). We observed no significant differences in neurocognitive testing in the MUNO vs. MHNO groups.
Conclusions: In this cross-sectional cohort study of younger adults, poor metabolic health and obesity are associated with subclinical brain aging. The prospective roles of optimal metabolic health and weight on brain health remain to be investigated.