Considering Deintensification and Deprescribing with Higher HbA1c Targets in Vulnerable Older Adults with Type 2 Diabetes: A Retrospective Database Study

In older adults with diabetes mellitus, guidelines recommend individualized hemoglobin (Hb) A1c targets based on cognitive impairment, functional status, and comorbidity burden, which collectively represent vulnerability. However, adherence to these recommendations in real-world clinical practice has not been well characterized. We aimed to investigate the association between vulnerability and incidence of severe hypoglycemia and to evaluate the distribution of HbA1c stratified by vulnerability- and drug-based categories. Using a Japanese claims database, we identified adults aged ≥ 65 years with type 2 diabetes who were prescribed outpatient glucose-lowering drugs with a 1-year baseline and up to 1-year follow-up. The most vulnerable patients were classified as category III (moderate-to-severe dementia or ≥ 4 of 8 comorbidities); all others were classified as category I + II. The outcome was incidence of severe hypoglycemia. Incidence rate ratios (IRRs) were estimated using negative binomial regression adjusted for covariates including age, comorbidities, prior severe hypoglycemia, and use of glucose-lowering drugs. HbA1c was summarized from health checkup results. Among 61,351 patients, 5221 (8.5%) were category III. Incidence of severe hypoglycemia was higher in category III than in category I + II (24.96 vs. 4.76 per 1000 person-years), and category III remained associated with severe hypoglycemia after adjustment (IRR 2.71, 95% confidence interval 2.00–3.68). Insulin/sulfonylurea/glinide-containing regimens and prior severe hypoglycemia were major risk factors. HbA1c levels were available for 15,372 patients, and category III more often had HbA1c < 6.5% (category III vs. category I + II, 315/649 [48.5%] vs. 5734/14,723 [38.9%]). Among 173 category III patients receiving insulin, sulfonylureas, or glinides, 133 (76.9%) had HbA1c below the recommended lower limit (7.5%). Vulnerable older adults with high comorbidity burden were at substantially higher risk of severe hypoglycemia. A large proportion of patients treated with hypoglycemia-prone agents had HbA1c levels below the recommended lower bounds, supporting medication review to guide deintensification and deprescribing.