Association Between Obesity and Cardiovascular Disease in Elderly Patients With Diabetes: A Retrospective Cohort Study

CONTEXT: Some studies have suggested that patients with type 2 diabetes mellitus (T2DM) concomitant with obesity have better clinical outcomes than normal-weight patients with T2DM. OBJECTIVE: We evaluated associations among obesity, cardiovascular disease (CVD) events, and mortality in elderly patients with T2DM without CVD. METHODS: This retrospective observational study from 2009 to 2017, with a mean follow-up of 7.26 years, included 249 903 elderly (≥ 65 years) patients with T2DM and no preexisting CVD from the Korean National Health Information Database. We categorized subjects according to body mass index (BMI) and waist circumference (WC) and analyzed a composite of stroke, myocardial infarction, and all-cause death using Cox proportional hazards regression analysis, adjusting for baseline covariates. RESULTS: The incidence rate of composite primary outcomes was 30.95/1000 person-years. The primary outcome risk had an L-shaped and a U-shaped association with BMI and WC, respectively. In the multivariable Cox proportional hazard models, the risk of primary composite outcomes in the highest BMI group (≥ 30 kg/m2; hazard ratio [HR] = 0.824; 95% CI, 0.794-0.855) was lower than in the normal BMI group (≥ 18.5 and < 23 kg/m2). Conversely, that in the highest WC group (≥ 100 cm/≥ 95 cm; men/women; HR = 1.434; 95% CI, 1.384-1.486) was higher than in the normal WC group (< 90 cm/< 85 cm; men/women). CONCLUSION: Our study with elderly patients with diabetes results suggest that while BMI is an inadequate risk indicator for outcomes related to obesity, WC is a suitable alternative.