Increased serum selenium levels are associated with reduced risk of advanced liver fibrosis and all-cause mortality in NAFLD patients: National Health and Nutrition Examination Survey (NHANES) III

Introduction and objectives Selenium supplementation has been shown to have therapeutic value in chronic liver disease. We aimed to investigate the association between serum selenium, severity of liver fibrosis, and mortality in patients with Nonalcoholic Fatty Liver Disease (NAFLD). Patients or material and methods A total of 33,944 patients were identified from the Third National Health and Nutrition Examination Survey. NAFLD was diagnosed by hepatic ultrasound after the exclusion of other forms of liver diseases. The severity of liver fibrosis was determined by NAFLD Fibrosis Score >0.676. Multivariate logistic regression analysis was used to investigate the relationship between serum selenium level and liver fibrosis. Association between serum selenium and all-cause mortality in NAFLD patients was also evaluated. Results Multivariate logistic regression analysis demonstrated odds ratio of advanced liver fibrosis (NFS > 0.676) was significantly reduced with increasing serum selenium levels; OR 0.55, [95% CI 0.32−0.94] in the highest selenium quartile. On stratification analysis, the following populations had a significantly reduced risk of advanced liver fibrosis: non-Hispanic white = OR 0.41 [0.24,0.68]; female = OR 0.32 [0.15−0.66] and age >47 = OR 0.47 [0.28−0.79]. The relationship was significant regardless of BMI as noted by BMI ≤ 30 Kg/m2= OR 0.42 [0.19−0.91] and BMI > 30 Kg/m2=OR 0.52 [0.28−0.97]. Hazard ratio for all-cause mortality was HR 0.72 [0.56−0.95]. Conclusions The risk of advanced liver fibrosis is inversely associated with serum selenium levels, particularly in older patients, Caucasians, and females. All-cause mortality decreased with increased selenium levels. Selenium may play a role in the prevention of liver fibrosis in NAFLD.