Low testosterone and non-alcoholic fatty liver disease: Evidence for their independent association in men with chronic spinal cord injury

Objective: Non-alcoholic fatty liver disease (NAFLD) has been claimed as a liver phenotype of metabolic syndrome, which in turn is associated with male hypogonadism. We assessed whether an independent association between NAFLD and androgen deficiency could be revealed in men with chronic spinal cord injury (SCI), who exhibit a high prevalence of biochemical androgen deficiency and a combination of risk factors for metabolic syndrome. Design: Fifty-five consecutive men with chronic SCI admitted to a rehabilitation program underwent clinical/biochemical evaluations and liver ultrasonography. Results: NAFLD was diagnosed in 27 patients (49.1%). Men with NAFLD were older and exhibited significantly higher body mass index, Homeostatic model assessment of insulin resistance, triglycerides and gammaglutamyl transpeptidase values, lower total and free testosterone levels and they were engaged in a significantly poorer weekly leisure time physical activity (LTPA). At the multiple logistic regression analysis, only total and free testosterone levels exhibited a significant independent association with NAFLD. The risk of having NAFLD increased indeed of 1% for each decrement of 1 ng/dL of total testosterone and of 3% for each decrement of 1 pg/mL of free testosterone, after adjustment for confounders. In men with total testosterone < 300 ng/dL (36.4%) the prevalence of NAFLD reached 85%: they had a risk of having NAFLD significantly higher (similar to 12-fold) than those with total testosterone >= 300 ng/dL, after adjustment for confounders. Conclusion: The evidence of an independent association between NAFLD and low testosterone is strongly reinforced by its demonstration in men with chronic SCI, in spite of the many confounders peculiar to this population.