Waist Circumference Change During Intensive Lifestyle Intervention and Cardiovascular Morbidity and Mortality in the Look AHEAD Trial

Objective The Action for Health in Diabetes (Look AHEAD) trial was a randomized trial comparing effects of intensive lifestyle intervention (ILI) and diabetes support and education (DSE) on cardiovascular disease (CVD) among individuals with overweight/obesity and type 2 diabetes. A secondary analysis was conducted to evaluate the association between change in weight and waist circumference (WC) and CVD outcomes. Methods Participants (N = 5,490) were classified into four categories based on change in weight and WC between baseline and year 1 (both increased, both decreased, etc.). Separate Cox proportional hazards regression models were fit for ILI and DSE (using group that reduced weight/WC as reference), and time to first occurrence of primary and secondary CVD outcomes from year 1 through a median of almost 10 years were compared. Second, time to first event among all four ILI groups relative to DSE was evaluated. Results Within DSE, CVD outcomes did not differ. ILI participants with increased WC had increased risk of primary outcomes, regardless of weight loss (hazard ratio: 1.55 [95% CI: 1.11-2.17]) or weight gain (hazard ratio: 1.76 [95% CI: 1.07-2.89]), and had increased risk of secondary outcomes (overallP < 0.01) relative to ILI participants who reduced both weight and WC and relative to DSE participants. Conclusions In this secondary analysis, increased WC during the first year of ILI, independent of weight change, was associated with higher risk for subsequent cardiovascular outcomes.