title: Association of Maternal Vitamin D Status with Glucose Tolerance and Caesarean Section in a Multi-Ethnic Asian Cohort: The Growing Up in Singapore Towards Healthy Outcomes Study.
abstract: OBJECTIVE
  Epidemiological studies relating maternal 25-hydroxyvitamin D (25OHD) with gestational diabetes mellitus (GDM) and mode of delivery have shown controversial results. We examined if maternal 25OHD status was associated with plasma glucose concentrations, risks of GDM and caesarean section in the Growing Up in Singapore Towards healthy Outcomes (GUSTO) study.
  
  
  METHODS
  Plasma 25OHD concentrations, fasting glucose (FG) and 2-hour postprandial glucose (2HPPG) concentrations were measured in 940 women from a Singapore mother-offspring cohort study at 26-28 weeks' gestation. 25OHD inadequacy and adequacy were defined based on concentrations of 25OHD ≤75nmol/l and >75nmol/l respectively. Mode of delivery was obtained from hospital records. Multiple linear regression was performed to examine the association between 25OHD status and glucose concentrations, while multiple logistic regression was performed to examine the association of 25OHD status with risks of GDM and caesarean section.
  
  
  RESULTS
  In total, 388 (41.3%) women had 25OHD inadequacy. Of these, 131 (33.8%), 155 (39.9%) and 102 (26.3%) were Chinese, Malay and Indian respectively. After adjustment for confounders, maternal 25OHD inadequacy was associated with higher FG concentrations (β = 0.08mmol/l, 95% Confidence Interval (CI) = 0.01, 0.14), but not 2HPPG concentrations and risk of GDM. A trend between 25OHD inadequacy and higher likelihood of emergency caesarean section (Odds Ratio (OR) = 1.39, 95% CI = 0.95, 2.05) was observed. On stratification by ethnicity, the association with higher FG concentrations was significant in Malay women (β = 0.19mmol/l, 95% CI = 0.04, 0.33), while risk of emergency caesarean section was greater in Chinese (OR = 1.90, 95% CI = 1.06, 3.43) and Indian women (OR = 2.41, 95% CI = 1.01, 5.73).
  
  
  CONCLUSIONS
  25OHD inadequacy is prevalent in pregnant Singaporean women, particularly among the Malay and Indian women. This is associated with higher FG concentrations in Malay women, and increased risk of emergency caesarean section in Chinese and Indian women.
authors.affiliation: KK Research Centre, KK Women's and Children's Hospital, Singapore.
authors.forename: See Ling
authors.initials: SL
authors.lastname: Loy
authors.affiliation: Duke-NUS Graduate Medical School, Singapore.|Department of Paediatrics, KK Women's and Children's Hospital, Singapore.
authors.forename: Ngee
authors.initials: N
authors.lastname: Lek
authors.affiliation: Duke-NUS Graduate Medical School, Singapore.|Department of Paediatrics, KK Women's and Children's Hospital, Singapore.
authors.forename: Fabian
authors.initials: F
authors.lastname: Yap
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, (A*STAR), Singapore.
authors.forename: Shu E
authors.initials: SE
authors.lastname: Soh
authors.affiliation: Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems, Singapore.
authors.forename: Natarajan
authors.initials: N
authors.lastname: Padmapriya
authors.affiliation: Division of Obstetrics and Gynaecology, KK Women's and Children's Hospital, Singapore.
authors.forename: Kok Hian
authors.initials: KH
authors.lastname: Tan
authors.affiliation: Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems, Singapore.
authors.forename: Arijit
authors.initials: A
authors.lastname: Biswas
authors.affiliation: Department of Maternal Fetal Medicine, KK Women's and Children's Hospital, Singapore.
authors.forename: George Seow Heong
authors.initials: GS
authors.lastname: Yeo
authors.affiliation: Department of Maternal Fetal Medicine, KK Women's and Children's Hospital, Singapore.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Kwek
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, (A*STAR), Singapore.|Liggins Institute, University of Auckland, Auckland, New Zealand.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Gluckman
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, United Kingdom.|NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom.
authors.forename: Keith M
authors.initials: KM
authors.lastname: Godfrey
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore.
authors.forename: Seang Mei
authors.initials: SM
authors.lastname: Saw
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore.|Institute for Social Medicine, Epidemiology and Health Economics, Charite University Medical Centre, Berlin, Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Müller-Riemenschneider
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, (A*STAR), Singapore.|Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, National University Health Systems, Singapore.
authors.forename: Yap-Seng
authors.initials: YS
authors.lastname: Chong
authors.affiliation: Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, (A*STAR), Singapore.|Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore.|Clinical Nutrition Research Centre, Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (A*STAR), Singapore.
authors.forename: Mary Foong-Fong
authors.initials: MF
authors.lastname: Chong
authors.affiliation: KK Research Centre, KK Women's and Children's Hospital, Singapore.|Duke-NUS Graduate Medical School, Singapore.|Department of Reproductive Medicine, KK Women's and Children's Hospital, Singapore.
authors.forename: Jerry Kok Yen
authors.initials: JK
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People; D001786:Blood Glucose / Q000032:analysis*; D002585:Cesarean Section; D015331:Cohort Studies; D016640:Diabetes, Gestational / Q000453:epidemiology*; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D039382:Maternal Nutritional Physiological Phenomena; D008875:Middle Aged; D016017:Odds Ratio; D019518:Postprandial Period; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood; D012044:Regression Analysis; D012307:Risk Factors; D012846:Singapore; D016896:Treatment Outcome; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D014807:Vitamin D; C104450:25-hydroxyvitamin D