Adiposity predicts cognitive decline in older persons with diabetes: A 2-year follow-up

The mechanisms related to cognitive impairment in older persons with Type 2 diabetes (DM) remains unclear. We tested if adiposity parameters and body fat distribution could predict cognitive decline in older persons with DM vs. normal glucose tolerance (NGT). Methodology: 693 older persons with no dementia were enrolled: 253 with DM in good metabolic control; 440 with NGT (age range:65-85 years). Longitudinal study comparing DM and NGT individuals according to the association of baseline adiposity parameters (body mass index (BMI), waist-hip-ratio (WHR), waist circumference (WC) and total body fat mass) to cognitive change (Mini Mental State Examination (MMSE), a composite score of executive and attention functioning (CCS) over time. Findings: At baseline, in DM participants, MMSE correlated with WHR (b =20.240; p = 0.043), WC (b =20.264; p = 0.041) while CCS correlated with WHR (b =20.238; p = 0.041), WC (b =20.326; p = 0.013) after adjusting for confounders. In NGT subjects, no significant correlations were found among any adiposity parameters and MMSE, while CCS was associated with WHR (b =20.194; p = 0.036) and WC (b =20.210; p = 0.024). Participants with DM in the 3rd tertile of total fat mass showed the greatest decline in cognitive performance compared to those in 1st tertile (tests for trend: MMSE(p = 0.007), CCS(p = 0.003)). Logistic regression models showed that 3rd vs. 1st tertile of total fat mass, WHR, and WC predicted an almost two-fold decline in cognitive function in DM subjects at 2nd yr (OR 1.68, 95%IC 1.08-3.52).