Adiposity Predicts Cognitive Decline in Older Persons with Diabetes: A 2-Year Follow-Up

Background 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 (β = −0.240; p = 0.043), WC (β = −0.264; p = 0.041) while CCS correlated with WHR (β = −0.238; p = 0.041), WC (β = −0.326; 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 (β = −0.194; p = 0.036) and WC (β = −0.210; p = 0.024). Participants with DM in the 3 rd tertile of total fat mass showed the greatest decline in cognitive performance compared to those in 1 st tertile (tests for trend: MMSE(p = 0.007), CCS(p = 0.003)). Logistic regression models showed that 3 rd vs. 1 st tertile of total fat mass, WHR, and WC predicted an almost two-fold decline in cognitive function in DM subjects at 2 nd yr (OR 1.68, 95%IC 1.08–3.52). Conclusions Total fat mass and central adiposity predict an increased risk for cognitive decline in older person with DM.