Factors associated with cognitive decline in older adults with type 2 diabetes mellitus during a 6-year observation

Aims: Type 2 diabetes mellitus (T2DM) is a risk for cognitive decline in older adults. The current study was carried out to determine the factors associated with cognitive decline. Methods: The older T2DM patients (aged >= 65 years, mean age 79.2 +/- 5.1 years) were observed for 6 years, and the mean values in clinical indicators of participants with and without cognitive decline over a 6-year period were compared. Then, multiple logistic analysis was carried out to determine the factors associated with cognitive decline. Separate analyses were also carried out for each of five cognitive assessments (Mini-Mental State Examination, word immediate and delayed recall, Stroop test, digit symbol substitution). Results: In the composite of several cognitive assessments, higher age and a lower level of high-density lipoprotein cholesterol were associated with cognitive decline in older T2DM patients. Lower systolic blood pressure was associated with a decline in delayed word list recall. Higher plasma insulin level was associated with a decline in the Stroop test performance. Conclusion: Lower high-density lipoprotein cholesterol was significantly associated with general cognitive decline in older T2DM patients during our 6-year observation. Several other factors were also associated with cognitive assessments of various cognitive domains.