Body roundness index and mortality risk in patients with chronic kidney disease: moving beyond the obesity paradox

Journal article

Background: Body roundness index (BRI), an emerging anthropometric measure, has been shown to outperform body mass index (BMI) in predicting mortality risk in the general population. However, its prognostic value among patients with chronic kidney disease (CKD), where the obesity paradox may exist, remains unknown. Methods: This observational study utilized data from the National Health and Nutrition Examination Survey. BRI was calculated using waist circumference (WC) and height, whereas BMI was calculated using body weight and height. Restricted cubic splines (RCSs) were applied to determine optimal cut-off points of BRI for all-cause and cardiovascular mortality in patients with CKD. Associations were examined using Cox proportional hazards models adjusted for potential confounders. Results: Over a median follow-up of 6.6 years, 6240 patients with CKD (mean age 63 years, 43% men) were included, with 1922 all-cause and 715 cardiovascular deaths recorded. RCSs demonstrated J-shaped associations between BRI with mortality. A BRI >10 was associated with a significantly increased risk of all-cause {adjusted hazard ratio [aHR] 1.82 [95% confidence interval (CI) 1.34–2.47]} and cardiovascular mortality [aHR 2.15 (95% CI 1.27–3.62)] compared with the reference of 5.9–6.8 and 5.9–6.5, respectively, with dose-response trends (P for trend < .05). A BMI >30 was paradoxically associated with 44% and 40% lower risks of all-cause and cardiovascular mortality compared with the reference of 18.5–25, respectively. A WC >125 was associated with an increased risk of all-cause mortality [aHR 2.17 (95% CI 1.47–3.18)] but not with cardiovascular mortality [aHR 1.83 (95% CI 0.97–3.45)] compared with the reference of 95–105 cm. The associations between BRI >10 and mortality risks were particularly pronounced among younger adults <65 years of age or individuals with elevated albuminuria (P for interaction < .05). Conclusions: Higher BRI was independently associated with increased all-cause and cardiovascular mortality risk among patients with CKD, offering greater prognostic value for risk stratification than BMI or WC.

Authors: Yang, C; Liao, B; Vart, P; Johnson, DW; Gansevoort, RT

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Nephrology Dialysis Transplantation
• Volume: 41
• Issue: 6
• Pages: 1118-1128
• Publication date: 2025-11-08
• Acceptance date: 2025-10-13
• DOI: 10.1093/ndt/gfaf237
• EISSN: 1460-2385
• ISSN: 0931-0509
• Language: English
• Keywords: waist circumference; body mass index; cardiovascular event; obesity; body roundness index