Association between weight-adjusted waist-index and symptoms of sleep apnea in US adults: results from 2015–2018 national health and nutrition examination survey

Abstract

Abstract Background Literature shows that traditional measures of obesity such as body mass index (BMI), waist-to-height ratio (WtHR), waist-to-hip ratio (WHR), and waist circumference (WC) may not be precise measures of obesity compared to weight-adjusted waist-index (WWI), a relatively new obesity index. BMI, WC, WHR, and WtHR were found to be associated with sleep apnea. However, the association between WWI and sleep apnea symptoms is not known. This study investigated the association between WWI and symptoms of sleep apnea among United States adults and compared WWI’s discriminative power with BMI, WtHR, WHR, and WC in the evaluation of symptoms of sleep apnea. Methods Data from the 2015–2018 National Health and Nutrition Examination Surveys were analyzed. WWI was calculated as WC (cm)/√weight (kg). A weighted multivariable logistic regression model and smooth curve fitting were used to investigate the association between WWI and sleep apnea symptoms. We generated the area under the receiver operating characteristics curve (ROC-AUC) to compare different obesity indices’ ability to distinguish those with and without sleep apnea symptoms. Results We analyzed data from 9,566 participants whose mean ± SD WWI was 11.03 ± 2.37 cm/√kg. The prevalence of sleep apnea symptoms was 13.10%. In the fully adjusted model, WWI was positively associated with symptoms of sleep apnea [Adjusted Odds Ratio = 1.71 95% Confidence Interval (CI): 1.32—2.21, p < 0.01]. Smoothing curve fitting showed a non-linear positive association between WWI and symptoms of sleep apnea. The ROC-AUCs were 0.63, 0.64, 0.63, 0.66, and 67 for WWI, BMI, WtHR, WC, and WHR, respectively. The association between WWI and symptoms of sleep apnea was consistent across different age groups, gender, asthma, and physical activity groups. Conclusion WWI was positively associated with increased odds of sleep apnea symptoms and the association showed a dose–response relationship. Our findings suggest that WWI can be used in the evaluation of symptoms of sleep apnea; however, prospective studies may be needed to confirm our findings.

Keywords

• Sleep apnea
• Weight-adjusted Waist Index
• Adiposity