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,Shang-Jyh Hwang,Ming-Yen Lin,Jer-Ming Chang,Jia-Jung Lee,Hung-Chun Chen,Chi-Chih Hung

doi:10.3390/jpm11121355

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.

Highlights

According to the World Health Organization, obesity has nearly tripled world widely since 1975 and has become an increasing health concern
J‐shaped relationship was found in male patients and a to body mass index (BMI), a reverse J-shaped relationship was found in male patients and a reverse association was found in female patients; for mortality according to central obesity (WHR, waist‐to‐height ratio (WHtR) and conicity index), a U-shaped relationship was found in both sexes
Pischon et al suggested the use of waist circumstance (WC) or waist-to-hip ratio (WHR) in addition to BMI in assessing mortality risk [11], and WC with normalization by hip and height was used as the anthropometric measure for central obesity in our study

Summary

Introduction

According to the World Health Organization, obesity has nearly tripled world widely since 1975 and has become an increasing health concern. Was related to the development of kidney disease in general population [1]. A J-shaped relationship between body mass index (BMI) and all-cause-mortality was discovered in the general population [2,3]. Obesity and probably overweight are associated with increased mortality, in particular with vascular disease including ischemic heart diseases and stroke [4]. High BMI is paradoxically linked with less mortality in dialysis patients, and this phenomenon is known as reverse epidemiology or the obesity paradox [5]. The reverse relationship between BMI and mortality has been noted in patients with advanced chronic kidney disease (CKD) [6]

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Conclusion