Importance of the Evaluation of Renal Function for the Prevention of Hypoglycemia in Elderly Diabetes Patients.

OBJECTIVE: The Japan Diabetes Society and the Japan Gerontological Society Collaborative Committee recently released guidelines for the management of elderly diabetes patients. In these guidelines, patients are classified into categories I-III depending on age, cognitive function, activities of daily living (ADL), and presence or absence of multiple functional impairments. The target control value of HbA1c is set for each category. Low (< 30 mL/min/1.73 m2) estimated glomerular filtration rate (eGFR) is an independent highrisk factor for severe hypoglycemia, yet it is not included in the categorization factors. We surveyed elderly diabetes patients with normal cognitive function and ADL (Category I) who were admitted to the emergency department with severe hypoglycemia, retrospectively studied eGFR at the onset of hypoglycemic episode, and checked whether the HbA1c levels matched the guidelines. METHODS: Among 129 diabetes patients aged ≥ 65 years admitted to the Tokai University hospital for hypoglycemic emergencies, 73 had normal cognitive function and ADL. HbA1c level and eGFR at the onset of hypoglycemic attack were obtained from the medical records of these subjects. RESULTS: All subjects were prescribed anti-diabetes agents with high-risk of severe hypoglycemia, including insulin. Sixty-one patients showed eGFR ≥ 30 mL/min/1.73 m2. Among them, 31 (50.8%) had HbA1c levels below the recommended range. Among 12 patients whose eGFR < 30 mL/min/1.73 m2, 6 (50%) had HbA1c levels below the recommended range. CONCLUSION: Even with normal cognitive function and ADL, eGFR < 30 mL/min/1.73 m2 a lone i s a s trong risk factor for hypoglycemia in elderly diabetes patients. We propose that the target control HbA1c level in elderly patients with eGFR < 30 mL/min/1.73 m2 should be 7.5-8.4 %, which is equivalent to that of category III patients.