Risk factors associated with cognitive decline in the elderly with type 2 diabetes: baseline data analysis of the Japanese Elderly Diabetes Intervention Trial.

Aim: Recent evidence has shown that type 2 diabetes mellitus (T2DM) in the elderly is a risk factor for cognitive dysfunction or dementia. However, the precise mechanisms have not yet been elucidated. In the current study, we attempted to elucidate the association of clinical indices and diabetic complications at baseline with cognitive declines after 6-year follow up in type 2 diabetic elderly.

Methods: The subjects were 261 participants who were administered the Mini-Mental State Examination (MMSE) at baseline and after 6 years, at the end of the observation period. The cognitive decline was determined as a 5-point or greater decline in MMSE scores during the observation period. Logistic regression analysis to find the factors associated with cognitive decline, adjusted for age and sex, were carried out, and factors with P-values of less than 0.2 were included in four models of multiple logistic regression analysis.

Results: We found that the existence of diabetic nephropathy, higher systolic blood pressure and higher serum triglycerides (or lower high-density lipoprotein cholesterol) at baseline were significantly associated with cognitive declines after 6 years in Japanese elderly diabetics in all four models.

Conclusion: The comorbidity of diabetic nephropathy, hypertension and hypertriglyceridemia at baseline were associated with more than 5-point declines in MMSE. Elucidation of the underlying mechanisms of this association is warranted.