Verification of Kumamoto Declaration 2013 and Glycemic Targets for Elderly Patients with Diabetes in Japan for prevention of diabetic complications: A retrospective longitudinal study using outpatient clinical data

AIMS/INTRODUCTION: The present study examined the association between the onset of micro‐ and macroangiopathy in type 2 diabetes mellitus patients and levels of glycated hemoglobin (HbA1c) described in the Evidence‐based Practice Guideline for the Treatment for Diabetes in Japan 2013 or those indicated in the Japan Diabetes Society and the Japan Geriatrics Society Joint Committee on Improving Care for Elderly Patients with Diabetes. MATERIALS AND METHODS: Patients with type 2 diabetes mellitus who visited the outpatient clinic at Kawasaki Medical School Hospital between 2000 and 2016 and received follow up for >2 years were eligible for the present study. Two datasets, comprising 2,424 or 3,316 patients without micro‐ or macroangiopathy at the start of follow up, were used, respectively. The Cox model was used in two categories of patients, younger and elderly, with the dividing line set at the age of 65 years. RESULTS: For the prevention of microangiopathy, in all patients, there was found to be no advantage in controlling HbA1c at a level of <6.0% based on the categories in the Evidence‐based Practice Guideline for the Treatment for Diabetes in Japan 2013, and there was found to be a disadvantage in maintaining HbA1c ≥8.5% based on the categories in the Japan Diabetes Society and the Japan Geriatrics Society Joint Committee on Improving Care for Elderly Patients with Diabetes guideline. For the prevention of macroangiopathy in younger patients, there seemed to be an advantage in maintaining HbA1c within the range of 6.0–6.9% and <7.0% based on the Evidence‐based Practice Guideline for the Treatment for Diabetes in Japan 2013 and the Japan Diabetes Society and the Japan Geriatrics Society Joint Committee on Improving Care for Elderly Patients with Diabetes, respectively. CONCLUSIONS: In all type 2 diabetes mellitus patients, average HbA1c should be maintained <7.0% to prevent microangiopathy. However, in elderly patients, no optimal target for preventing macroangiopathy was found, in contrast to the younger patients in the present study.