Sex Differences in the Association of Weight-Adjusted-Waist Index with Sarcopenic Obesity: A Cross-Sectional Study of Hemodialysis Patients.

Objective: To explore the association between weight-adjusted-waist index (WWI) and sarcopenic obesity (SO) in patients with maintenance hemodialysis (MHD). Methods: A multicenter, cross-sectional study that included 3311 adult MHD patients was conducted in 20 hemodialysis (HD) centers from June 1, 2021, to August 30, 2021. Body composition was evaluated by body composition monitor based on bioimpedance spectroscopy. Hand grip strength was measured by CAMRY^® dynamometer. WWI was calculated as waist circumference (cm) divided by the square root of body weight (kg). Multiple logistic regression models, spearman correlation analysis, and receiver-operating characteristic (ROC) analyses were conducted. Results: The median age of the study was 55 years, and 39.4% of patients were female. The prevalence of SO was 22.7% in the total population, and patients with SO had higher WWI. Higher WWI quartiles were independently associated with a higher risk of SO in men after adjusting for potential confounders, including age, dialysis vintage, body mass index, biochemical indicators, and various medical histories; the odds ratio (OR) of SO was highest in the fourth quartile of the WWI (OR: 4.08, 95% confidence interval: 2.65-6.27, P for trend <0.001). Age-adjusted WWI provided a better diagnostic power than WWI only for SO in men (area under the ROC curve: 0.72 vs. 0.68, P < 0.001). WWI was not associated with SO in female HD patients. Conclusion: WWI is independently associated with SO in male but not female MHD patients. This anthropometric index is simple to calculate, making it applicable in clinical practice.