Low hemoglobin A1c and low body mass index are associated with dementia and activities of daily living disability among Japanese nursing home residents with diabetes: HbA1c and dementia or ADL in nursing homes

AIM: To investigate associations between glycemic control and dementia, activities of daily living (ADL), falls and fractures in Japanese older adults with type 2 diabetes mellitus living in nursing homes. METHODS: A total of 384 older residents with diabetes aged ≥65 years from 95 out of 132 facilities in Hiroshima Prefecture were studied in a cross-sectional study in 2016. Primary outcomes were differences in severity of dementia and ADL among three glycosylated hemoglobin level groups. Secondary end-points included differences in falls, fragility fracture and severe hypoglycemia. RESULTS: Approximately 67.6% of patients receiving any diabetes treatment received dipeptidyl peptidase-4 inhibitors, and 26.0% received sulfonylureas. Patients with glycosylated hemoglobin <7.0% had a significantly higher severity of dementia compared with those with glycosylated hemoglobin 7.0-7.9% (beta ± SE, 0.55 ± 0.26; 95% CI 0.04-1.06) in multivariable ordinal logistic regression analysis. This tendency was observed particularly in patients using insulin (1.91 ± 0.91; 95% CI 0.13-3.69) or both sulfonylureas and dipeptidyl peptidase 4 (2.14 ± 0.88; 95% CI 0.41-3.87). Low body mass index was significantly associated with dementia (-0.08 ± 0.03; 95% CI -0.14 - -0.03) and ADL impairment (-0.15 ± 0.03; 95% CI -0.20 - -0.09), and fractures (odds ratio OR 0.89 per kg/m2 ; 95% CI 0.84-0.96). CONCLUSIONS: Tight glycemic control was related to dementia in residents treated with insulin and sulfonylureas, and low body mass index was associated with dementia, ADL disability and fractures. Optimization of glycemic control and weight for people with diabetes in long-term care facilities could be important for the maintenance of cognitive and physical function. Geriatr Gerontol Int 2019; 19: 854-860.