title: Hypovitaminosis D is associated with increased whole body fat mass and greater severity of non-alcoholic fatty liver disease.
abstract: OBJECTIVE
  Hypovitaminosis D is common in obesity and insulin-resistant states. Increased fat mass in patients with non-alcoholic fatty liver disease (NAFLD) may contribute to hypovitaminosis D. To determine the relation among plasma vitamin D concentration, severity of disease and body composition in NAFLD.
  
  
  METHODS
  Plasma vitamin D concentration was quantified in 148 consecutive biopsy-proven patients with NAFLD (non-alcoholic steatohepatitis - NASH: n = 81; and hepatic steatosis: n = 67) and healthy controls (n = 39). NAFLD was scored using the NASH CRN criteria. Body composition was quantified by bioelectrical impedance analysis and abdominal CT image analysis.
  
  
  RESULTS
  Plasma vitamin D concentration was significantly lower in NAFLD (21.2 ± 10.4 ng/ml) compared with healthy controls (35.7 ± 6.0 ng/ml). Higher NAFLD activity scores were associated with lower plasma concentration of vitamin D (r(2)  = 0.29; P < 0.001). Subgroup analysis among patients with NAFLD showed that patients with NASH had significantly lower (P < 0.01) vitamin D levels than those with steatosis alone (18.1 ± 8.4 vs. 25.0 ± 11.3 ng/ml). Low concentrations of vitamin D were associated with greater severity of steatosis, hepatocyte ballooning and fibrosis (P < 0.05).On multivariate regression analysis, only severity of hepatocyte ballooning was independently associated (P = 0.02) with low vitamin D concentrations. Plasma vitamin D (P = 0.004) and insulin concentrations (P = 0.03) were independent predictors of the NAFLD activity score on biopsy. Patients with NAFLD had higher fat mass that correlated with low vitamin D (r(2)  = 0.26; P = 0.008).
  
  
  CONCLUSIONS
  Low plasma vitamin D concentration is an independent predictor of the severity of NAFLD. Further prospective studies demonstrating the impact of vitamin D replacement in NAFLD patients are required.
authors.affiliation: Department of Family Medicine, MetroHealth Medical Center, Cleveland, OH, USA.
authors.forename: Jaividhya
authors.initials: J
authors.lastname: Dasarathy
authors.forename: Pranav
authors.initials: P
authors.lastname: Periyalwar
authors.forename: Sanath
authors.initials: S
authors.lastname: Allampati
authors.forename: Vikram
authors.initials: V
authors.lastname: Bhinder
authors.forename: Carol
authors.initials: C
authors.lastname: Hawkins
authors.forename: Patricia
authors.initials: P
authors.lastname: Brandt
authors.forename: Amer
authors.initials: A
authors.lastname: Khiyami
authors.forename: Arthur J
authors.initials: AJ
authors.lastname: McCullough
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Dasarathy
mesh_terms: D050153:Abdominal Fat / Q000000981:diagnostic imaging / Q000503:physiopathology; D050154:Adiposity; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D017097:Electric Impedance; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D065626:Non-alcoholic Fatty Liver Disease / Q000175:diagnosis / Q000453:epidemiology*; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D014807:Vitamin D / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*
chemical_list: D015415:Biomarkers; D014807:Vitamin D
keywords: body composition; fat mass; metabolic syndrome; non-alcoholic fatty liver disease; vitamin D