title: Osteocalcin is higher across pregnancy in Caucasian women with gestational diabetes mellitus.
abstract: OBJECTIVE
  The purpose of this study was to investigate circulating concentrations of osteocalcin, a bone-derived protein, while accounting for 25-hydroxyvitamin D (25(OH)D) throughout pregnancy, and whether early gestation concentrations and changes in osteocalcin predict the subsequent diagnosis of gestational diabetes mellitus (GDM).
  
  
  METHODS
  This was a nested case-control study involving 48 GDM and 48 control pregnant Caucasian women (matched for age, season of conception, pre-pregnancy body mass index and pregnancy length). Maternal serum osteocalcin was measured by enzyme-linked immunosorbent assay and 25(OH)D by chemiluminescence throughout pregnancy (11-13 weeks, 24-28 weeks and predelivery). Differences between groups were compared by mixed model analysis of variance. Predictors of diagnosis of GDM were explored using generalized estimating equation models. Neonatal general health outcomes were also compared between groups.
  
  
  RESULTS
  Serum osteocalcin was higher across pregnancy (p=0.006) in women with GDM vs. controls, whereas serum 25(OH)D was not different (p=0.80). Both biomarkers increased with time across pregnancy (p<0.0001). However, serum osteocalcin during early pregnancy and changes in its concentration from early to mid gestation did not predict the development of GDM. There were no significant differences in anthropometry and APGAR (appearance, pulse, grimace, activity, respiration) scores in neonates of controls and cases.
  
  
  CONCLUSIONS
  Serum osteocalcin is elevated in Caucasian women with GDM throughout pregnancy, but was not predictive of the onset of GDM. Larger trials evaluating the role of osteocalcin and the development of GDM appear warranted.
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Ste-Anne-de-Bellevue, Quebec, Canada.
authors.forename: Negar
authors.initials: N
authors.lastname: Tabatabaei
authors.affiliation: Centre Hospitalier Universitaire de Québec Research Centre et Faculté de médecine, Université Laval, Québec City, Quebec, Canada.
authors.forename: Yves
authors.initials: Y
authors.lastname: Giguère
authors.affiliation: Centre Hospitalier Universitaire de Québec Research Centre et Faculté de médecine, Université Laval, Québec City, Quebec, Canada.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Forest
authors.affiliation: Department of Pediatrics, Montreal Children's Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: Celia J
authors.initials: CJ
authors.lastname: Rodd
authors.affiliation: Department of Medicine, Calcium Research Laboratory, McGill University, Montreal, Quebec, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Kremer
authors.affiliation: School of Dietetics and Human Nutrition, McGill University, Ste-Anne-de-Bellevue, Quebec, Canada. Electronic address: hope.weiler@mcgill.ca.
authors.forename: Hope A
authors.initials: HA
authors.lastname: Weiler
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D016640:Diabetes, Gestational / Q000097:blood* / Q000453:epidemiology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008163:Luminescent Measurements; D008297:Male; D015675:Osteocalcin / Q000097:blood*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D044465:White People
chemical_list: D015415:Biomarkers; D015675:Osteocalcin; D014807:Vitamin D; C104450:25-hydroxyvitamin D
keywords: diabète gestationnel; gestational diabetes; osteocalcin; ostéocalcine; vitamin D; vitamine D