title: Low 25-hydroxyvitamin D level is associated with insulin sensitivity in obese adolescents with non-alcoholic fatty liver disease.
abstract: OBJECTIVE
  The aim of this study was to investigate the relationships between 25-hydroxy-vitamin D (25(OH)D) and insulin resistance in obese adolescents with non-alcoholic fatty liver disease (NAFLD).
  
  
  METHODS
  Eighty-seven obese adolescents (45 girls and 42 boys, mean age: 12.7 ± 1.3 years, mean body mass index standard deviation score (BMI-SDS): 2.1 ± 0.3) and 30 lean subjects (15 girls and 15 boys, mean age: 12.3 ± 1.45 years, mean BMI-SDS: 0.5 ± 0.7) were enrolled for the study. The obese subjects were divided into two subgroups based on the presence or absence of fatty liver with high transaminases (NAFLD group and non-NAFLD group). Fasting blood samples were assayed for 25(OH)D, transaminases, glucose, and insulin levels. Insulin resistance was calculated by the homeostasis model assessment (HOMA-IR).
  
  
  RESULTS
  25(OH)D measurements were decreased in both obese groups (NAFLD and non-NAFLD) in comparison with the lean group (29.5 ± 18.4 vs. 41.0 ± 17.9 vs. 48.1 ± 22.2 ng/mL). However; the NAFLD group had significantly lower measurements of 25(OH)D than the non-NAFLD group (p < 0.001) and lean group (p < 0.001). 25(OH)D was negatively correlated with HOMA-IR (r = 0.158, p = 0.01) and with alanine aminotransferase (r = 0.794, p = 0.03) in the NAFLD obese group. There was no significant associations between fasting insulin, BMI-SDS and 25(OH)D in obese groups.
  
  
  CONCLUSIONS
  We suggest that low 25(OH)D occurs commonly in obese adolescents with NAFLD and we demonstrated an association between insufficient vitamin D status and low insulin sensitivity in obese adolescents with NAFLD.
authors.affiliation: Department of Pediatric Endocrinology and Diabetes, Konya Research Hospital, Konya, Turkey. Electronic address:ozpirgon@hotmail.com.
authors.forename: Ozgur
authors.initials: O
authors.lastname: Pirgon
authors.forename: Ferhat
authors.initials: F
authors.lastname: Cekmez
authors.forename: Huseyin
authors.initials: H
authors.lastname: Bilgin
authors.forename: Esra
authors.initials: E
authors.lastname: Eren
authors.forename: Bumin
authors.initials: B
authors.lastname: Dundar
mesh_terms: D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D001794:Blood Pressure; D015992:Body Mass Index; D001835:Body Weight; D016022:Case-Control Studies; D002648:Child; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005234:Fatty Liver / Q000097:blood* / Q000150:complications; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008099:Liver / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D065626:Non-alcoholic Fatty Liver Disease; D063766:Pediatric Obesity / Q000097:blood* / Q000150:complications; D012307:Risk Factors; D014463:Ultrasonography; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007328:Insulin; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase