title: Relationship between lactation duration and insulin and glucose response among women with prior gestational diabetes.
abstract: BACKGROUND
  Few studies have investigated whether favorable effects of lactation persist after weaning and protect women with prior gestational diabetes mellitus (GDM) against later development of insulin resistance and insulin secretion defects.
  
  
  OBJECTIVE
  To investigate the impact of lactation duration on insulin and glucose response among women with prior GDM.
  
  
  METHODS
  The study group comprised 144 women with a history of GDM between 2003 and 2010. Plasma insulin and glucose concentrations were obtained from a 75 g oral glucose tolerance test (OGTT). Total lactation duration (exclusive breastfeeding and breast and bottle-feeding) for all infants was self-reported in months.
  
  
  RESULTS
  Mean age was 36.5±5.0 years. Time between delivery and metabolic testing was 4.0±1.9 years. Women breastfed for an average of 13.9±16.8 months. Most women (80.6%) reported a history of lactation. Women who lactated had higher homeostasis model assessment for insulin sensitivity (HOMA-IS) and Matsuda indices and lower fasting and 2-h post-OGTT insulin concentrations as well as area under the curve (AUC) for insulin (P≤0.01 for all). Compared with women who lactated for <10 months, women who lactated for ≥10 months had improved insulin sensitivity-secretion index, higher HOMA-IS and Matsuda indices, lower fasting and 2-h post-OGTT insulin concentrations as well as AUC for insulin, and lower incidence of impaired glucose intolerance (P≤0.05 for all). In multiple linear regression analyses, lactation duration emerged as an independent predictor of fasting insulin concentrations (β=-0.02) and insulin sensitivity indices (β=0.02) (P≤0.05 for all).
  
  
  CONCLUSIONS
  These results suggest that longer duration of lactation is associated with improved insulin and glucose response among women with prior GDM.
authors.affiliation: Department of Food Science and Nutrition, Laval University, Quebec City, Quebec, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Chouinard-Castonguay
authors.forename: S John
authors.initials: SJ
authors.lastname: Weisnagel
authors.forename: André
authors.initials: A
authors.lastname: Tchernof
authors.forename: Julie
authors.initials: J
authors.lastname: Robitaille
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D001942:Breast Feeding / Q000639:trends; D016640:Diabetes, Gestational / Q000453:epidemiology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007328:Insulin / Q000378:metabolism*; D007774:Lactation / Q000378:metabolism*; D011247:Pregnancy; D011795:Surveys and Questionnaires; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin