Low BMI and high waist-to-hip ratio are associated with mortality risk among hemodialysis patients: a multicenter prospective cohort study

Yaya Yang; Haixia Zhang; Xiaolei Lan; Xianhui Qin; Yan Huang; Jieyu Wang; Pei Luo; Zhen Wen; Yumin Li; Yaozhong Kong; Qijun Wan; Qi Wang; Sheng Huang; Yan Liu; Aiqun Liu; Fanna Liu; Shenglin Yang; Yongxin Lu; Yanhong Zhao; Junzhi Chen; Zihan Lei; Yanhuan He; Zizhen Lin; Youbao Li; Min Liang

doi:10.1093/ckj/sfac210

Low BMI and high waist-to-hip ratio are associated with mortality risk among hemodialysis patients: a multicenter prospective cohort study

Clin Kidney J. 2022 Sep 15;16(1):167-175. doi: 10.1093/ckj/sfac210. eCollection 2023 Jan.

Authors

Yaya Yang¹, Haixia Zhang¹, Xiaolei Lan¹, Xianhui Qin¹, Yan Huang¹, Jieyu Wang¹, Pei Luo¹, Zhen Wen¹, Yumin Li¹, Yaozhong Kong², Qijun Wan³, Qi Wang⁴, Sheng Huang⁵, Yan Liu⁶, Aiqun Liu⁷, Fanna Liu⁸, Shenglin Yang¹, Yongxin Lu⁹, Yanhong Zhao⁹, Junzhi Chen¹, Zihan Lei¹, Yanhuan He¹, Zizhen Lin¹, Youbao Li¹, Min Liang¹

Affiliations

¹ National Clinical Research Center for Kidney Disease, Nanfang Hospital, Guangdong Provincial Clinical Research Center for Kidney Disease; State Key Laboratory of Organ Failure Research; Nephrology Department, Nanfang Hospital, Southern Medical University, Guangzhou, China.
² Nephrology Department, the First People's Hospital of Foshan, Foshan, China.
³ Nephrology Department, Shenzhen Second People's Hospital, Shenzhen, China.
⁴ Nephrology Department, Huadu District People's Hospital of Guangzhou, Guangzhou, China.
⁵ Nephrology Department, Southern Medical University Affiliated Nanhai Hospital, Foshan, China.
⁶ Nephrology Department, Guangzhou Red Cross Hospital, Medical College of Jinan University, Guangzhou, China.
⁷ Nephrology Department, The Third Affiliated Hospital of Southern Medical University, Guangzhou, China.
⁸ Nephrology Department, Jinan University First Affiliated Hospital, Guangzhou, China.
⁹ Nephrology Department, People's Hospital of Yuxi City, Yuxi, China.

Abstract

Background: Data are limited on the relationship between waist-to-hip ratio (WHR) and mortality risk among maintenance hemodialysis (MHD) patients. Moreover, the combined association of body mass index (BMI) and WHR with mortality remains uncertain. Therefore, we aimed to explore the individual and combined association of BMI and WHR with the all-cause and cardiovascular disease (CVD) mortality.

Methods: In this multicenter prospective cohort study, we enrolled 1034 MHD patients. The primary outcome was all-cause mortality and secondary outcome was CVD mortality. Multivariable Cox proportional hazards models were used to evaluate the individual and combined association of BMI and WHR with the risk of mortality.

Results: A nonlinear inverse relationship was found between BMI and risk of all-cause mortality (P for nonlinearity <.05). Being underweight (<18.5 kg/m²) was associated with higher all-cause mortality risk (HR 1.45; 95% CI 1.08-1.94) compared with normal weight (18.5-23.9 kg/m²), while being overweight (24-27.9 kg/m²; HR 0.96; 95% CI 0.70-1.31) and obese (≥28 kg/m²; HR 1.19; 95% CI 0.62-2.26) showed no significant differences. Of note, WHR was independently and positively associated with all-cause mortality (per standard deviation increase, HR 1.13; 95% CI 1.00-1.27). When analyzed jointly, patients with low BMI (<18.5 kg/m²) and high WHR (≥0.95) had the highest risk of all-cause mortality. Similar results were obtained for CVD mortality.

Conclusions: In patients undergoing hemodialysis from China, low BMI and high WHR were individually and jointly associated with higher risk of mortality. Our results emphasize that BMI and WHR may jointly affect the prognosis of MHD patients.

Keywords: all-cause mortality; body mass index; cardiovascular mortality; hemodialysis; waist-to-hip ratio.