title: Strong association between non alcoholic fatty liver disease (NAFLD) and low 25(OH) vitamin D levels in an adult population with normal serum liver enzymes.
abstract: BACKGROUND
  Hypovitaminosis D has been recently recognized as a worldwide epidemic. Since vitamin D exerts significant metabolic activities, comprising free fatty acids (FFA) flux regulation from the periphery to the liver, its deficiency may promote fat deposition into the hepatocytes. Aim of our study was to test the hypothesis of a direct association between hypovitaminosis D and the presence of NAFLD in subjects with various degree of insulin-resistance and related metabolic disorders.
  
  
  METHODS
  We studied 262 consecutive subjects referred to the Diabetes and Metabolic Diseases clinics for metabolic evaluation. NAFLD (non-alcoholic fatty liver disease) was diagnosed by upper abdomen ultrasonography, metabolic syndrome was identified according to the Third Report of National Cholesterol Education Program/Adult Treatment Panel (NCEP/ATPIII) modified criteria. Insulin-resistance was evaluated by means of HOMA-IR. Fatty-Liver-Index, a recently identified correlate of NAFLD, was also estimated. Serum 25(OH)vitamin D was measured by colorimetric method.
  
  
  RESULTS
  Patients with NAFLD (n=162,61.8%) had reduced serum 25(OH) vitamin D levels compared to subjects without NAFLD (14.8±9.2 vs 20.5±9.7 ng/ml, p<0.001, OR 0.95, IC 95% 0.92-0.98). The relationship between NAFLD and reduced 25(OH)vitamin D levels was independent from age, sex, triglycerides, high density lipoproteins (HDL) and glycaemia (p<0.005) and Fatty Liver Index inversely correlated with low 25(OH) vitamin D regardless sex, age and HOMA-IR (p<0.007).
  
  
  CONCLUSIONS
  Low 25(OH)vitamin D levels are associated with the presence of NAFLD independently from metabolic syndrome, diabetes and insulin-resistance profile.
authors.affiliation: Department of Internal Medicine and Medical Specialties, Sapienza University of Rome, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Barchetta
authors.forename: Francesco
authors.initials: F
authors.lastname: Angelico
authors.forename: Maria
authors.initials: M
authors.lastname: Del Ben
authors.forename: Marco Giorgio
authors.initials: MG
authors.lastname: Baroni
authors.forename: Paolo
authors.initials: P
authors.lastname: Pozzilli
authors.forename: Sergio
authors.initials: S
authors.lastname: Morini
authors.forename: Maria Gisella
authors.initials: MG
authors.lastname: Cavallo
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging; D000328:Adult; D005234:Fatty Liver / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D008099:Liver / Q000201:enzymology; D008297:Male; D024821:Metabolic Syndrome / Q000175:diagnosis; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease; D044967:Serum / Q000737:chemistry / Q000201:enzymology; D014463:Ultrasonography; D014807:Vitamin D / Q000097:blood*; D014808:Vitamin D Deficiency / Q000150:complications* / Q000453:epidemiology*
chemical_list: D014807:Vitamin D