Hyperuricemia is associated with histological liver damage in patients with non-alcoholic fatty liver disease

Background Hyperuricemia has been associated with metabolic disorders. In this line recent studies observed an independent link between higher uric acid serum levels and clinical diagnosis of non-alcoholic fatty liver disease (NAFLD). Aims We aimed to assess the potential association between uric acid serum levels and histological liver damage in a homogeneous cohort of biopsy-proven NAFLD patients. Methods Consecutive NAFLD patients (n = 166), assessed by liver biopsy (Kleiner score), anthropometric, biochemical and metabolic features, were included. Enzymatic colorimetric test was used for serum uric acid assays (Roche Diagnostics GmbH, Mannheim, Germany). Hyperuricemia was diagnosed when uric acid serum levels were >7 mg/dL in men, and >6 mg/dL in women. Results Mean uric acid serum level was 5.75 mg/dL, and about 20% of patients had hyperuricemia, that was independently associated with younger age (OR 0.951, 95% CI 0.918-0.984, P = 0.004), lobular inflammation (OR 2.144, 95% CI 1.055-4.357, P = 0.03) and steatosis grade (OR 1.859, 95% CI 1.078-3.205, P = 0.02), by multivariate logistic regression analysis. Female gender (OR 2.656, 95% CI 1.190-5.928, P = 0.01), higher HOMA index (OR 1.219, 95% CI 1.043-1.426, P = 0.01), and hyperuricemia (OR 4.906, 95% CI 1.683-14.296, P = 0.004) were linked to NAFLD activity score (NAS) >= 5 by multiple logistic regression analysis. Conversely, higher HOMA index (OR 1.140, 95% CI 1.001-1.229, P = 0.04), and NAS (OR1.954, 95% CI 1.442-2.649, P < 0.001) were independently associated with significant fibrosis by logistic regression analysis. Conclusions In NAFLD patients, hyperuricemia is independently associated with the severity of liver damage, representing, in this setting of patients, together with insulin resistance, a potential new therapeutic target in future intervention trials.