Body mass index and mortality among Japanese patients with type 2 diabetes: Pooled analysis of the Japan diabetes complications study and the Japanese elderly diabetes intervention trial

Abstract

Context: Previous studies on the association between body mass index (BMI) and mortality in diabetes do not necessarily provide a comprehensive view in terms of the global population because of the exclusion of individuals with a BMI less than 18.5 kg/m2. Objective: The objective of the study was to examine the association between BMI and mortality. Design, Setting, and Participants: We analyzed pooled data from 2 cohorts of 2620 Japanese patients with type 2 diabetes followed up for 6.3 years. Patients with a history of cardiovascular disease or cancer were excluded. Main Outcome Measure: The end point was all-cause mortality. Hazard ratios were estimated by Cox regression adjusted for age, smoking, leisure-time physical activity, and other confounders. Results: An analysis using BMI categories of 14.4-18.5 (5.2%), 18.5-22.4 (37.3%), 22.5-24.9 (31.0%), and 25.0-37.5 kg/m2 (26.6%) revealed no significant trend in mortality among patients with a BMI of 18.5 kg/m2 or greater (trend P = .69). In contrast, the hazard ratio of patients with a BMI less than 18.5 kg/m2 vs 22.5-24.9 kg/m2 was 2.58 (95% confidence interval 1.38-4.84; P