Association of waist-to-height ratio with all-cause and obesity-related mortality in adults: a prospective cohort study

Abstract

Background: The waist-to-height ratio (WHtR) is the optimal indicator for assessing obesity-related diseases. Establishing a unified standard for investigating the relationship between WHtR and mortality is an urgent need. Methods: This cohort study included 47,741 U. S. adults from the National Health and Nutrition Examination Survey database from 1999 to 2018. The survival outcomes were all-cause mortality and obesity-related mortality. The associations between WHtR and mortality were quantified using restricted cubic splines and Cox proportional hazards regression models. Results: Among the 47,741 participants, the association between WHtR and all-cause mortality was characterized by a distinct U-shaped curve, with an inflection point at 0.58. The relative risk was minimized in the Q3 category, with a hazard ratio of 0.753 (95% CI, 0.752–0.754). WHtR demonstrated a J-shaped nonlinear relationship with the risk of mortality from cardiovascular disease, cancer, and diabetes (p < 0.001), with an inflection point of 0.58 for each condition. A higher WHtR (≥0.58) was associated with increased risks of mortality from cardiovascular disease (35.5%), cancer (4.5%), cerebrovascular disease (10.0%), and diabetes (69.8%). In subgroup analyses, the cutoff value of 0.58 for WHtR showed good stability across different populations. Conclusion: We found that the WHtR is associated with all-cause mortality in a U-shaped manner and provides a relatively stable cutoff value (0.58) for mortality related to obesity-associated diseases. This finding offers a convenient anthropometric indicator for body management in the general population.