Abstract
OBJECTIVE: To assess the complementary role of the Body Mass Index (BMI) and Edmonton Obesity Staging System (EOSS) in predicting all-cause and cause-specific mortality in people living with overweight and obesity (PLwOW/O). METHODS: A longitudinal analysis of prospectively collected data from the 1999-2018 cycles of the National Health and Nutrition Examination Survey (NHANES) was conducted. The association between BMI, EOSS, and mortality was evaluated through Cox regression models, adjusted for confounders. RESULTS: The analysis included 36,529 subjects; 5329 deaths occurred over a median follow-up of 9.1 years (range: 0-20.8). An increased mortality risk was observed for obesity class II and III (HR = 1.21, 95% CI 1.08-1.36, p = 0.001 and HR = 1.58, 95% CI 1.39-1.80, p < 0.001; compared to overweight), and for EOSS stage 2 and 3 (HR = 1.36, 95% CI 1.16-1.58, p < 0.001 and HR = 2.66, 95% CI 2.26-3.14, p < 0.001; compared to stage 0/1). The prognostic role of BMI was more pronounced in younger patients, males, and non-Black individuals, while that of EOSS was stronger in women. Both BMI and EOSS independently predicted cardiovascular- and diabetes-related mortality. EOSS stage 3 was the only predictor of death from malignancy or renal causes. CONCLUSIONS: BMI and EOSS independently predict all-cause and cause-specific mortality in PLwOW/O. Their integrated use seems advisable to best define the obesity-related mortality risk.