Relationship between obesity-related indicators and adult depression from NHANES 2021 to 2023: A cross-sectional study.

Obesity has been demonstrated to influence the onset and progression of depression. However, previous research has predominantly examined the association between depression and single indicators such as body mass index (BMI) or weight-adjusted waist index (WWI). While an increase in WWI and BMI correlates positively with depression scores, no studies have investigated the relationship between comprehensive obesity-related indicators - Waist-to-hip ratio (WHtR), WWI, BMI, and waist circumference (WC) - and depression scores. Using data from the National Health and Nutrition Examination Survey as the research subject, this analytical cross-sectional study used receiver operating characteristic curves, smooth curve fitting, multivariate regression analysis, and subgroup analysis to examine the association between depression, BMI, WC, WHtR, and WWI. This study included 5042 participants. WWI, WC, WHtR, and BMI showed positive correlations with depression scores (P < .001). There was no statistically significant difference in the relationship between BMI and depression scores according to gender and age. In the smooth curve fitting analysis, WC, WHtR, and BMI exhibited nonlinear positive correlations at inflection points of 97.6, 0.58, and 27.6, respectively. In predicting depression, the receiver operating characteristic values for WHtR, BMI, WWI, and WC showed little difference. The findings of this study indicate that body weight indicators - WWI, WC, WHtR, and BMI - are associated with depression risk. Key thresholds were identified, including WC 97.6 cm, WHtR 0.58, and BMI 27.6 kg/m2, and the impact of BMI on depression remained stable across different gender and age subgroups. Lifestyle interventions targeting these indicators may effectively prevent and mitigate the progression of depression.