Impact of diabetes and utility of antidiabetic medications on physical and cognitive functioning of older Mexican Americans: A population-based cohort study

The population of Mexican Americans in the US has increased dramatically over the past several decades. Older Mexican Americans are at high risk for diabetes, its complications, and other comorbidities. A significantly higher decline rate in physical and cognitive functioning might exist in older Mexican Americans with diabetes, as compared to those without diabetes. Decline in physical and cognitive functioning is often associated with disability, dementia, impaired quality of life, and substantial increase in social and economic burden. However, earlier studies have not examined these important issues due to various intrinsic limitations. Also, little is known about whether antidiabetic medications could attenuate the decline in physical and cognitive functioning in this population. This study performed a longitudinal analysis to examine these important issues in a population-based sample of older Mexican Americans. Data analysis was conducted using a generalized estimating equation.; Among the 1,789 participants in the Sacramento Area Latino Study on Aging (SALSA) project, 585 (33%) had diabetes at baseline. There was a more rapid decline in physical functioning over 2 years among older Mexican Americans with diabetes, as compared to non-diabetic subjects. Both diabetes-related complications and a longer duration of diabetes were associated with more rapid functional decline in diabetic subjects. The rate of decline in the cognitive score over 2 years among diabetic subjects was greater than that of the non-diabetic subjects. Sensitivity test for major cognitive decline also showed similar results. Cognitive decline was associated with the severity of diabetes (as indicated by the number of complications). The effect of diabetes on changes in cognitive functioning was significantly modified by the presence of stroke. Antidiabetic drugs appeared to be useful in alleviating the decline in physical and cognitive functioning among older Mexican Americans with diabetes, especially for those with a longer duration of the disease. Combination therapy of antidiabetic agents appeared to be more effective than monotherapy in preventing the decline in physical and cognitive functioning for subjects.