Metabolic Dysfunction-Associated Steatotic Liver Disease and Vascular Complications: Associations with Serum Testosterone Levels in a Korean Multicenter Male Cohort.

BACKGROUND/AIMS: We investigated the associations of testosterone levels with metabolic dysfunction-associated steatotic liver disease (MASLD) and vascular complications in a large Korean male cohort. Despite the high global prevalence of MASLD and significant morbidity from cardiovascular disease, the interplay among testosterone levels, MASLD, and vascular outcomes remains unclear, particularly in Asian populations. METHODS: This cross-sectional study analyzed 1,167 men from the Korean Health Screening-Based MASLD Registry. MASLD was defined as imaging-confirmed steatosis with metabolic dysfunction. Log2-transformed testosterone levels were analyzed using logistic regression adjusted for metabolic risk factors to evaluate associations with MASLD, advanced fibrosis (Fibrosis-4 index [FIB-4] ≥1.3), carotid plaques, and cerebrovascular accidents (CVAs). RESULTS: Among the 1,167 men (mean age 57.0 years), 730 (62.6%) had MASLD. These patients had lower testosterone levels than non-MASLD men did (223.5 ng/dL vs 347.5 ng/dL; p<0.001) and showed adverse metabolic features. Higher testosterone levels were independently associated with reduced risk of MASLD (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.85 to 0.94; p<0.001). Among the MASLD patients, higher testosterone levels were linked to a significantly lower prevalence of carotid plaques (OR, 0.77; 95% CI, 0.73 to 0.81) and CVAs (OR, 0.75; 95% CI, 0.67 to 0.82). The associations remained robust across sensitivity analyses with adjustments for obesity, diabetes, and dyslipidemia. No significant association was observed with advanced fibrosis (FIB-4 ≥1.3). CONCLUSIONS: Low testosterone levels are independently associated with MASLD and its vascular complications but not with advanced fibrosis. Serum testosterone levels may serve as a practical biomarker for metabolic and vascular risk stratification in MASLD patients, warranting validation in prospective and interventional studies. (ClinicalTrials.gov identifier NCT06843421).