Association between weight-adjusted waist index and serum total testosterone in males aged 6–19 years in the United States: Data from NHANES 2013–2016

This study aimed to estimate the association between weight-adjusted waist index and serum total testosterone (sTT) in males aged 6–19 years in the United States. A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2013–2016. sTT was considered as the response variable, and weight-adjusted waist circumference index (WWI) as the independent variable. Multiple linear regression was performed to estimate the association between the two variables, and subgroup analysis was performed to identify sensitive cohorts. Smoothing curve fitting and threshold effects analysis was carried out to assess possible nonlinear relationships between WWI and sTT. The study included 4207 participants. The mean value of sTT (117.93 ng/dl) was used as the grouping basis, with 1066 participants having serum total testosterone levels above the mean. A negative association was observed between WWI and sTT [beta coefficient (β) = −72.50, 95% confidence interval (CI): -79.45, −65.55], which decreased as WWI increased (P for trend