(HealthDay)—For patients with type 2 diabetes mellitus (T2DM), fasting plasma glucose (FPG) visit-to-visit variation, represented by the coefficient of variation (CV), and hemoglobin A1c (HbA1c) CV are independently associated with Alzheimer's disease (AD), according to a study published online July 13 in Diabetes Care.

Tsai-Chung Li, Ph.D., from China Medical University in Taiwan, and colleagues included 16,706 patients with T2DM in the National Diabetes Care Management Program who were age 60 years or more and without diagnosis of AD. The authors sought to examine the correlation between glycemic variability and incidence of AD.

The researchers identified 831 incident cases of AD during a median follow-up of 8.88 years, with a crude incidence rate of 3.5/1,000 person-years. Both FPG CV and HbA1c CV were significant predictors of AD after adjustment for sociodemographic factors, lifestyle behaviors, diabetes-related variables, FPG and HbA1c, drug-related variables, and comorbidities, with hazard ratios of 1.27 and 1.32 for the third tertiles of FPG CV and HbA1c CV, respectively.

"The associations between glycemic variability and AD demonstrated in this study suggest a linked pathophysiological mechanism, which is worthy of further investigation," the authors write.