U-Shaped Association between Waist-to-Hip Ratio and All-Cause Mortality in Stage 3-5 Chronic Kidney Disease Patients with Body Mass Index Paradox

Feng-Ching Shen; Yi-Wen Chiu; Mei-Chuan Kuo; Ming-Yen Lin; Jia-Jung Lee; Shang-Jyh Hwang; Jer-Ming Chang; Chi-Chih Hung; Hung-Chun Chen

doi:10.3390/jpm11121355

U-Shaped Association between Waist-to-Hip Ratio and All-Cause Mortality in Stage 3-5 Chronic Kidney Disease Patients with Body Mass Index Paradox

J Pers Med. 2021 Dec 13;11(12):1355. doi: 10.3390/jpm11121355.

Authors

Feng-Ching Shen¹, Yi-Wen Chiu^{1

2}, Mei-Chuan Kuo¹, Ming-Yen Lin¹, Jia-Jung Lee^{1

3}, Shang-Jyh Hwang^{1

2}, Jer-Ming Chang^{1

2}, Chi-Chih Hung^{1

3}, Hung-Chun Chen^{1

2}

Affiliations

¹ Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
² Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
³ Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.

Abstract

The obesity paradox, referring to the association of high body mass index (BMI) with low all-cause mortality risk, is found in patients with chronic kidney disease (CKD). Central obesity is associated with metabolic syndrome and may have better prognostic value than BMI for all-cause mortality. Whether central obesity is associated with all-cause mortality in cases of obesity paradox in CKD patients remains unknown. We included 3262 patients with stage 3-5 CKD, grouped into five quintiles (Q1-5) by waist-to-hip ratio (WHR). Low WHR and BMI were associated with malnutrition and inflammation. In Cox regression, high BMI was not associated with all-cause mortality, but BMI < 22.5 kg/m² increased the mortality risk. A U-shaped association between central obesity and all-cause mortality was found: WHR Q1, Q4, and Q5 had higher risk for all-cause mortality. The hazard ratio (95% confidence interval) of WHR Q5 and Q1 for all-cause mortality was 1.39 (1.03-1.87) and 1.53 (1.13-2.05) in male and 1.42 (1.02-1.99) and 1.28 (0.88-1.85) in female, respectively. Waist-to-height ratio and conicity index showed similar results. Low WHR or low BMI and high WHR, but not high BMI, are associated with all-cause mortality in advanced CKD.

Keywords: advanced chronic kidney disease; all-cause mortality; body mass index; central obesity; conicity index; obesity paradox; waist-to-height ratio; waist-to-hip ratio.