Ratio of waist circumference to body mass index: A novel predictor of clinical outcome in hypertension patients

We aim to investigate the influence of waist circumference and body mass index (BMI) on all-cause death and cardiovascular-specific death in patients with hypertension. This prospective cohort study, based on waist circumference and body mass index measurements in patients with hypertension, provided risk estimates of all-cause mortality and cardiovascular events. The waist circumference-to-BMI ratio (WtBR) is an anthropometric measure integrating waist circumference and BMI. We utilized multivariable Cox regression analysis, restricted cubic spline model, Kaplan-Meier plot, random forest analysis, and sensitivity analysis to assess the relationship of WtBR with all-cause mortality. Subsequently, Fine-Gray competing risk regression models were applied to precisely evaluate the probability of cardiovascular-specific death attributed to high WtBR. The results indicate that thea deceased group showed significantly higher WtBR and lower BMI compared with the alive groups (P < .05), while no significant difference was observed in waist circumference (P = .373). When analyzed as continuous, the risk of all-cause death elevated with increasing WtBR in the adjusted model with an HR of 2.42 (95% CI, 2.06-2.85). The restricted cubic spline illustrated an elevated risk of all-cause mortality as WtBR increased (J-shaped curve). Nevertheless, WtBR showed no significant association with cardiovascular-specific death and the prediction model exhibited a reliable performance in the testing set. This study supported that WtBR, an anthropometric measure, is independently associated with all-cause death in hypertensive patients. It's advisable to routinely assess waist circumference in hypertensive patients regardless of BMI, in order to more effectively manage the risk of obesity-related health.