title: Glucose homeostasis, beta cell function, and insulin resistance in relation to vitamin D status after gestational diabetes mellitus.
abstract: BACKGROUND
  We wanted to determine vitamin D status after gestational diabetes mellitus (GDM) and to evaluate whether levels of 25-hydroxyvitamin D3(25OHD3) are associated with beta cell function, insulin resistance or a diagnosis of diabetes after GDM.
  
  
  METHODS
  Glucose homeostasis was assessed during a 75-g oral glucose tolerance test one to two years after delivery in 376 women with previous GDM (287 European and 78 non-European, including 33 Arab and 35 Asian women). Insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR). The insulinogenic index (I/G30) and the disposition index [(I/G30)/HOMA-IR] were used to calculate insulin secretion. Concentrations of serum 25OHD3were determined.
  
  
  RESULTS
  Mean (±SD) 25OHD3concentration was 50.0 ± 22.3 nmol/L and differed significantly among subgroups of body mass index, ethnicity, and glucose tolerance status; 53% had 25OHD3levels <50 nmol/L and 87% had 25OHD3levels <75 nmol/L. There was a negative correlation between 25OHD3concentration and HOMA-IR (p < 0.001) and a positive correlation between 25OHD3and disposition index (p = 0.002) in univariable regression analysis. Correlations attenuated after adjustment for body mass index. In univariable regression analysis, 25OHD3concentrations were significantly associated with diabetes after GDM (p = 0.004). However, in a multivariable model, non-European origin, HOMA-IR and insulinogenic index were significantly associated with postpartum diabetes, whereas 25OHD3concentrations were not.
  
  
  CONCLUSIONS
  Vitamin D deficiency/insufficiency in previous GDM cases appears to be associated with beta cell dysfunction and insulin resistance, but not with postpartum diabetes when factors well known to influence type-2 diabetes were adjusted for.
authors.affiliation: Department of Clinical Sciences, Lund University, Malmö, Sweden.|Department of Endocrinology, Skåne University Hospital, Malmö, Sweden.
authors.forename: Nael
authors.identifier: http://orcid.org/0000-0001-9163-8699
authors.initials: N
authors.lastname: Shaat
authors.affiliation: Department of Clinical Sciences, Lund University, Malmö, Sweden.|Department of Obstetrics and Gynecology, Office for Healthcare "Sund", Helsingborg, Sweden.
authors.forename: Claes
authors.identifier: http://orcid.org/0000-0001-7317-1861
authors.initials: C
authors.lastname: Ignell
authors.affiliation: Department of Clinical Sciences, Lund University, Malmö, Sweden.|Department of Endocrinology, Skåne University Hospital, Malmö, Sweden.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Katsarou
authors.affiliation: Department of Clinical Sciences, Lund University, Malmö, Sweden.|Department of Endocrinology, Skåne University Hospital, Malmö, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Berntorp
mesh_terms: D000328:Adult; D018912:Arabs; D044466:Asian People; D001786:Blood Glucose / Q000502:physiology; D002112:Calcifediol / Q000097:blood*; D016640:Diabetes, Gestational / Q000097:blood* / Q000208:ethnology; D005006:Ethnicity; D005260:Female; D006706:Homeostasis; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology; D050417:Insulin-Secreting Cells / Q000502:physiology; D049590:Postpartum Period / Q000097:blood; D011247:Pregnancy; D013548:Sweden; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D002112:Calcifediol
keywords: Disposition index; HOMA-IR; OGTT; ethnicity; gestational diabetes; insulinogenic index; postpartum diabetes; vitamin D