The association between weight-adjusted waist index and sleep disorders in U.S. adults: results from NHANES 2005–2008

The detrimental effects of obesity on sleep disorders have garnered a lot of interest. The weight-adjusted waist index (WWI) is a newly developed anthropometric index calculated in terms of weight and waist circumference. The body mass index has been employed to evaluate obesity in the majority of studies that connect obesity to sleep disorders. This study seeks to investigate the correlation between WWI and sleep disorders among adults in the United States. This cross-sectional study was part of the National Health and Nutrition Examination Survey and included adults aged >20 from 2005 to 2008. This study investigated the linear relationship between sleep disorders and WWI using weighted binary logistic regression models. Nonlinear relationships were characterized using smooth curve fitting and threshold effects analyses. After that, based on variables like gender, age, marital status, diabetes, hypertension, and smoking, subgroup analyses were performed. Our study included 9869 participants who were at least 20 years old. Higher WWI was linked to greater odds of sleep disorders prevalence, according to weighted binary logistic regression (odds ratio = 1.15; 95% confidence interval, 1.10, 1.20). In subgroup analyses based on age, marital status, diabetes, hypertension, and smoking, this connection remained robust. However, there were notable differences in this connection depending on gender. Furthermore, a nonlinear correlation with inflection points between WWI and sleep disorders was shown using smooth curve fitting. The nonlinear association between WWI and sleep disorders has an inflection point of 8.1 cm/√kg, as indicated by the threshold effect analyses. A higher WWI exposure may elevate the odds of sleep disorder prevalence, underscoring the importance of considering WWI in the prevention and management of sleep disorders.