Vitamin D Deficiency, A Noninvasive Marker of Steatohepatitis in Patients with Obesity and Biopsy Proven Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) includes simple steatosis, steatohepatitis (NASH) which can evolve with progressive fibrosis, cirrhosis and hepatocellular carcinoma. As liver biopsy cannot be used as a screening method, noninvasive markers are needed.The aim of this study was to test if there is a significant association between vitamin D deficit and the severity of NAFLD.The patients were divided into two groups (vitamin D insufficiency/deficiency) and statistical analyses were performed on the correlation of clinical and biochemical characteristics with histopathological hepatic changes.We prospectively studied 64 obese patients referred for bariatric surgery between 2014 and 2016 to our Surgical Unit. Anthropometric, clinical measurements, general and specific biological balance were noted. NAFLD diagnosis and activity score (NAS) were evaluated on liver biopsies.Increased serum fibrinogen was correlated with NASH (p=0.005) and higher NAS grade. T2DM was positively correlated with liver fibrosis (p=0.002). 84.37% of the patients had vitamin D deficit and 15.62% were vitamin D insufficient. Lobular inflammation correlated with vitamin D deficit (p=0.040). Fibrosis (p=0.050) and steatohepatitis (p=0.032) were independent predictors of low vitamin D concentration.Vitamin D status in conjunction with other parameters - such as T2DM - or serum biomarkers - namely fibrinogen level and PCR level - may point out the aggressive forms of NAFLD and the need for liver biopsy for appropriate management.