Exploring the non-linear association and threshold effect of sedentary behavior on testosterone deficiency.

Background: Sedentary behavior has emerged as a potential risk factor for various health issues, including hormonal imbalances like testosterone deficiency (TD). However, the relationship between sedentary time and TD remains underexplored, especially with respect to the complex biological mechanisms underlying this association. This study aimed to examine the association between sedentary time and TD in adult males.

Methods: This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey 2011-2016. A total of 6057 male participants aged 20 years and older were included. Sedentary time was categorized into quartiles, and TD was defined as serum testosterone levels below 300 ng/dL. Logistic regression models were employed to assess the association between sedentary time and TD, adjusting for demographic, lifestyle, and health-related covariates. Restricted cubic spline (RCS) analysis and segmented regression were also conducted to explore potential non-linear relationships and thresholds. Subgroup analyses were performed to examine the consistency of associations across various groups.

Results: The analysis revealed a significant positive association between sedentary time and TD. Prolonged sedentary behaviour was consistently associated with higher odds of TD across all models (all p < 0.001). RCS analysis showed a significant non-linear relationship, particularly as sedentary time exceeded 4.5 h per day, with a marked increase in the likelihood of TD (p-non-linear = 0.027). Subgroup analysis indicated that this association was most pronounced in Non-Hispanic Whites, current smokers, and drinkers, and was weaker in individuals with diabetes, where the association lost statistical significance after full adjustment.

Conclusions: This study identifies a significant association between prolonged sedentary behaviour and a higher risk of TD, suggesting that sedentary behavior may play a key role in the development of TD, particularly in specific high-risk populations.