Association between serum testosterone level and cardiovascular health in US male adults: results from the 2013-2016 NHANES.

Background: There have been many studies of the association between testosterone and cardiovascular disease (CVD). However, limited research has examined the association between testosterone and Life's Essential 8 (LE8), a recently updated algorithm for assessing cardiovascular health (CVH).

Objectives: This study aims to investigate the association between serum total testosterone (TT) levels and LE8 scores-where higher LE8 scores indicate better CVH-among adult males in the United States.

Method: Data from 3308 adult males were extracted from the National Health and Nutrition Examination Survey conducted between 2013 and 2016. Weighted univariate and multivariate linear regression models [β and 95% confidence intervals (CIs)] and logistic regression models [odds ratios (ORs) and 95% CIs] were used to explore the association between testosterone and LE8 and high CVH risk. Additionally, a smoothed curve fit (penalized spline method) and generalized additive model regression were applied to further explore these relationships.

Outcomes: LE8 includes 4 health behaviors (nicotine exposure, diet, physical activity, and sleep duration) and 4 health factors (body mass index, non-high-density lipoprotein cholesterol, blood pressure, and blood glucose).

Results: Serum TT levels were strongly associated with LE8 scores after adjusting for all confounders (continuous: β = 2.75, 95% CI: 1.92, 3.57, P < .0001; quartiles: Q4 vs Q1: β = 3.89, 95% CI: 2.78, 5.01, P < .0001). Similarly, high levels of TT were associated with a significantly lower CVH risk (OR = 0.59, 95% CI: 0.49, 0.73, P < .001). Compared to low TT levels, normal TT levels significantly reduced the risk of CVH (OR = 0.51, 95% CI: 0.38, 0.69, P < .001). Smoothed curve fitting showed a positive linear correlation between TT levels and LE8 scores, as well as a consistent linear negative correlation with CVH risk.

Clinical implications: These findings highlight the importance of endogenous TT levels in promoting CVH and provide new insights into factors influencing CVH.

Strengths and limitations: This study is the first to investigate the association between serum TT level and LE8 scores as well as LE8-assessed CVH among adult males. However, the observational nature of this study precludes any assessment of causality.

Conclusions: This study demonstrates a robust positive association between serum TT levels and LE8 scores in a nationally representative sample of adult men in the United States.