Waist circumference, not BMI, a good indicator of outcomes in older diabetics

In older patients with type 2 diabetes (T2D), use of body mass index (BMI) does not adequately predict clinical outcomes associated with obesity, but waist circumference (WC) appears to be up to the task.

This retrospective observational study was conducted from 2009 to 2017 and evaluated associations among obesity, cardiovascular disease (CVD) events, and mortality in older patients with T2D without CVD. A total of 249,903 participants aged ≥65 years were identified from the Korean National Health Information Database. Mean follow-up was 7.26 years.

The authors categorized patients according to BMI and WC. They also analysed a composite of stroke, myocardial infarction, and all-cause mortality (the primary outcome) using Cox proportional hazards regression analysis, adjusting for baseline covariates.

The incidence rate of composite outcomes was 30.95 per 1,000 person-years. The primary outcome risk exhibited L- and U-shaped associations with BMI and WC, respectively.

Multivariable analysis revealed a lower risk of composite outcomes in the highest BMI group (≥30 kg/m²; hazard ratio [HR], 0.824, 95 percent confidence interval [CI], 0.794‒0.855) than in the normal BMI group (≥18.5 and <23 kg/m²).

On the other hand, the risk of composite outcomes was higher in the highest WC group (≥100 cm/≥95 cm; men/women; HR, 1.434, 95 percent CI, 1.384-1.486) than in the normal WC group (<90 cm/<85 cm; men/women).

“Some studies have suggested that patients with T2DM concomitant with obesity have better clinical outcomes than normal-weight patients with T2D,” the authors noted.