Clinical features and sulfonylurea usage among outpatients with diabetes aged ≥90 years in an urban diabetes clinic in Tokyo

AIMS/INTRODUCTION: Aging of society is accelerating in many countries. The purpose of this study was to describe the clinical features and sulfonylurea usage among diabetes outpatients aged ≥90 years (nonagenarians). MATERIALS AND METHODS: This study was a retrospective observational study. The study population consisted of 69 nonagenarian diabetes outpatients and 857 diabetes outpatients aged <90 years. Patients were classified into four groups: group 1, <65 years; group 2, 65–74 years; group 3, 75–89 years; and group 4, ≥90 years. The presence of hypoglycemic episodes was defined as having self‐reported symptoms, or self‐monitored or clinically measured blood glucose level <70 mg/dL. RESULTS: The median glycated hemoglobin (HbA1c) in group 1 and group 4 was 7.0% and 7.2%, respectively (P = 0.506). The proportion of sulfonylurea treatment in group 4 was 45.5%, which is significantly higher compared with the other three groups (20.0–27.8%, P < 0.001). In group 4, there was no difference between patients with or without sulfonylurea in age, sex, body mass index, HbA1c and number of antihyperglycemic agents. Five out of 25 nonagenarian sulfonylurea‐treated patients had hypoglycemic episodes within the last 2 years, their HbA1c were all 7.0 ≤ HbA1c < 8.0, and sulfonylurea or insulin was tapered in all cases after confirming hypoglycemia. Tapering dosage was attempted in all 25 sulfonylurea‐treated nonagenarian patients, but 15 needed to continue sulfonylurea for glycemic control, and 10 continued sulfonylurea with unknown reasons from their medical records. CONCLUSIONS: Although tapering the dosage of sulfonylurea was attempted in nonagenarian patients, sulfonylurea was widely continued for glycemic control. Reverse clinical inertia may exist in some sulfonylurea‐treated nonagenarian patients.