Effect of Diabetes Mellitus on Daily Functioning and Cognition of Alzheimer's Disease Patients Evaluated by DASC-21

Introduction: Diabetes mellitus (DM) is a risk factor for Alzheimer’s disease (AD). It has also been pointed out that AD associated with DM may have unique characteristics. However, the characteristics of impairment in daily functioning when associated with DM have not been sufficiently investigated. Methods: In the present study, we compared the characteristics of 261 patients with AD diagnosed in the outpatient memory clinic of a university hospital, divided into diabetic and nondiabetic groups. The MMSE was used to assess cognitive function, and the Dementia Assessment Sheet for Community-based Integrated Care System 21-items (DASC-21) was used as an observational method to assess cognitive function and activities of daily livings. The two groups were compared. Furthermore, simple and multiple regression analysis was carried out in order to find the independent association of age, sex, education, DM, and HbA1c with the DASC-21 and each individual item of the DASC-21. Results: Diabetic subjects were as follows: MMSE 18.8 ± 4.0, DASC-21 46.0 ± 13.2, and HbA1c 7.07 ± 1.24%, respectively. On the other hand, nondiabetic subjects were as follows: MMSE 19.0 ± 4.5 and DASC-21 42.1 ± 12.2, respectively. In the diabetic group, total score of DASC-21 was higher (DM vs. nondiabetes mellitus [NDM]: 46.0 ± 13.2 vs. 42.1 ± 12.2; p < 0.05) and solving issues and common sense on the DASC-21 were higher than in the nondiabetic group (NDM) (DM vs. NDM: 8.58 ± 2.71 vs. 7.76 ± 2.66; p < 0.05). Multiple regression analysis showed that the presence of DM was the significant determinant of solving issues and common sense on the DASC-21 (p < 0.05). Conclusions: In AD patients, DM may be associated with impairment of solving issues and common sense.