A low level of serum total testosterone is independently associated with nonalcoholic fatty liver disease

Abstract
The association between low serum testosterone levels, visceral adipose tissue (VAT), and metabolic syndrome is now well known. However, the relationship between hepatic steatosis and serum testosterone levels has not been extensively studied. Our aim was to investigate the association of serum total testosterone levels with nonalcoholic fatty liver disease (NAFLD), adjusting for the influence of VAT and insulin resistance. This study is a retrospective observational cross-sectional one of healthy Korean men and was conducted at the Seoul National University Hospital Healthcare System Gangnam Center. We used data obtained from 495 men who were at least 20 years of age and who had undergone blood testing, abdominal computed tomography, and ultrasonography. Multiple logistic regression analysis was used to explore the association of serum total testosterone levels with NAFLD. Men in the low serum testosterone quintile were at a higher risk for NAFLD than men in the highest serum testosterone quintile. After adjusting for age, smoking, diabetes, exercise, BMI, triglycerides, and high-density-lipoprotein cholesterol, subjects with serum testosterone levels in the lowest quintile had an odds ratio (OR) (95% confidence interval (CI)) of 5.12 (2.43–10.77) for NAFLD (p value, 0.0004). The inverse association between serum testosterone and NAFLD was attenuated by further adjustment for variables including VAT; however, it remained statistically significant (OR (95% CI): 4.52 (2.09–9.80) in the lowest quintile; p value=0.004). A low serum total testosterone level was independently associated with NAFLD. This report is the first one suggesting the association remains unchanged even after controlling for VAT and insulin resistance.