title: Correlation between vitamin D3 deficiency and insulin resistance in pregnancy.
abstract: BACKGROUND
  The serum level of 25-hydroxyvitamin D deficiency has long been suspected as a risk factor for glucose intolerance and perhaps 1,25-dihydroxyvitamin D has a role in the regulation of insulin secretion. This study investigates the relation between 25-hydroxyvitamin D concentrations and insulin resistance in pregnant women.
  
  
  METHODS
  A cross-sectional study was conducted on 741 pregnant women referred to five educating hospital clinics. Universal screening was performed with a GCT-50 g, and those with plasma glucose levels > pr = 7.2 mmol/L were diagnosed as GDM if they had an impaired GTT-100 g based on Carpenter and Coustan criteria. The levels of insulin and C-peptide were measured during OGTT-100 g test. The homeostasis model assessment index (HOMA) equation was used as the insulin resistance index. The concentrations of 25-hydroxyvitamin D, and PTH were also measured.
  
  
  RESULTS
  Total prevalence of vitamin D deficiency (<25 nmol/L) was found in 70.6% of pregnant women. Prevalence of severe vitamin D deficiency (<12.5) in GDM patients was higher than in normoglycaemic pregnancies. The regression model revealed a strong correlation between the HOMA index and serum levels of vitamin D.
  
  
  CONCLUSIONS
  These results show that a positive correlation of 25(OH) vitamin D concentrations with insulin sensitivity and vitamin D deficiency could be a confirmative sign of insulin resistance.
authors.affiliation: Endocrinology & Metabolism Research Center, Tehran University of Medical Sciences, Tehran, Iran. emrc@sina.tums.ac.ir
authors.forename: Zhila
authors.initials: Z
authors.lastname: Maghbooli
authors.forename: Arash
authors.initials: A
authors.lastname: Hossein-Nezhad
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Karimi
authors.forename: Ali-Reza
authors.initials: AR
authors.lastname: Shafaei
authors.forename: Bagher
authors.initials: B
authors.lastname: Larijani
mesh_terms: D000328:Adult; D002096:C-Peptide / Q000097:blood; D002762:Cholecalciferol / Q000172:deficiency*; D003430:Cross-Sectional Studies; D016640:Diabetes, Gestational / Q000097:blood / Q000175:diagnosis; D005260:Female; D005951:Glucose Tolerance Test; D006706:Homeostasis; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D010281:Parathyroid Hormone / Q000097:blood; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000503:physiopathology*
chemical_list: D002096:C-Peptide; D007328:Insulin; D010281:Parathyroid Hormone; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D