Functional categories based on cognition and activities of daily living predict all-cause mortality in older adults with diabetes mellitus: The Japanese Elderly Diabetes Intervention Trial.

Aim: Although the glycemic target in older diabetes patients is based on cognition, activities of daily living and multimorbidity in the Japanese guideline, evidence of the relationships is limited. Thus, we aimed to assess the relationship between functional category and mortality in older people with diabetes.

Methods: We evaluated the data of 843 older diabetes patients in a 6-year prospective study, and the association between functional categories and all-cause mortality. The patients were divided into three functional categories based on cognition, instrumental activities of daily living and basic activities of daily living using the Mini-Mental State Examination, Tokyo Metropolitan Institute of Gerontology Index of Competence and Barthel Index at baseline, respectively (model 1). Those with multimorbidity (≥4 of 8 morbidities) were classified into category III (model 2). The functional category assessed using eight items from the Tokyo Metropolitan Institute of Gerontology Index of Competence and Barthel Index was also constructed (model 3). Hazard ratios and 95% confidence intervals were calculated in the Cox regression analysis using age, sex, body mass index, glycated hemoglobin level, total cholesterol level, estimated glomerular filtration rate and frequency of severe hypoglycemia as covariates.

Results: During the 6-year follow up, 64 incident mortalities occurred. The hazard ratios for mortality in categories II and III (as the reference of category I) were 1.83 (95% confidence interval 1.06-3.14, P = 0.030) and 3.05 (95% confidence interval 1.12-8.26, P = 0.029) after adjustment for covariates, respectively (model 1). Models 2 and 3 showed similar associations between functional category and mortality.

Conclusions: The functional categories predicted all-cause mortality in older adults with diabetes. Geriatr Gerontol Int 2021; 21: 512-518.