The waist-to-body mass index ratio is a better predictor for cardiovascular outcome in patients with established atherosclerotic cardiovascular disease - No u-shaped phenomenon

Abstract Background Many studies have observed an “obesity paradox” in patients with established atherosclerotic cardiovascular disease (ASCVD), in which the body mass index (BMI)-mortality curve is U-shaped. Purpose To search a better anthropometric parameter to predict the cardiovascular events in patients with ASCVD. Methods The study was conducted from the Taiwanese Secondary Prevention for patients with AtheRosCLErotic disease (T-SPARCLE) Registry. Adult patients with stable ASCVD were enrolled. The primary composite endpoint of this study is the time of the first major cardiovascular event, defined as cardiovascular death, nonfatal myocardial infarction or stroke, or cardiac arrest with resuscitation. Dose response association between primary outcome events and various traditional anthropometric parameters and a new parameter, the waist-to-BMI ratio, was examined using the Cox proportional hazards regression model. We used restricted cubic spline regression to investigate the potential nonlinear relationship between each anthropometric measure and primary outcome events. Results A total of 6921 patients with ASCVD were included in this analysis, and were followed up for a median of 2.5 years. Multivariable Cox proportional hazards regression showed a significant positive association between the waist-to-BMI ratio and the primary outcome events (adjusted hazard ratio 1.67, 95% CI 1.12–2.49, p=0.01). Other traditional anthropometric parameters, such as BMI, weight, waist and waist-hip ratio, did not showed significant associations (p=0.10, 0.31, 0.90, and 0.52, respectively). In the restricted cubic spline regression, the positive dose response association between the primary outcome and the waist-to-BMI ratio persisted across all the waist-to-BMI ratio, and was non-linear (the likelihood ratio test for nonlinearity was statistically significant, p<0.001) with a much steeper increase in the major cardiovascular event for the waist-to-BMI ratio >3.6 cm m2/kg. Dose response curve of waist/BMI ratio Conclusion This study found the waist-to-BMI ratio to be a better predictor for major adverse cardiovascular events in established ASCVD patients than other traditional anthropometric parameters.