title: Testing the fuel-mediated hypothesis: maternal insulin resistance and glucose mediate the association between maternal and neonatal adiposity, the Healthy Start study.
abstract: OBJECTIVE
  In women who are overweight or obese before or during pregnancy there is an associated risk of increased fetal growth and higher birthweight. The metabolic phenotype of the overweight/obese pregnant woman, characterised by higher than normal insulin resistance (IR) and increased circulating fuels, suggests a mechanism resulting in fetal overnutrition and subsequent increased adiposity. We tested the fuel-mediated hypothesis in an observational pre-birth cohort of 951 mother-offspring pairs, the Healthy Start study.
  
  
  METHODS
  We conducted a path analysis to estimate the simultaneous effects of maternal IR and maternal fuels (fasting glucose, triacylglycerol [TG] and NEFA levels) in late pregnancy in mediating the relationship between maternal pre-pregnancy BMI and neonatal adiposity (per cent fat mass [%FM]).
  
  
  RESULTS
  The total effect of maternal BMI on neonatal %FM was significant (total effect 0.16, 95% CI 0.08, 0.22, p < 0.001). The mediated path including maternal IR and glucose levels together accounted for 21% (p < 0.01) of the total effect of maternal BMI on neonatal %FM while the mediating effects of all other fuels were non-significant.
  
  
  CONCLUSIONS
  Using a novel application of path analysis our data implicate maternal IR and glucose levels as important mediators of the association between maternal and infant adiposity.
authors: Department of Epidemiology, Colorado School of Public Health, Campus Box B119, 13001 East 17th Ave, Room W3110, Aurora, CO, 80045, USA.
authors: Allison L B
authors: AL
authors: Shapiro
authors: Sarah J
authors: SJ
authors: Schmiege
authors: John T
authors: JT
authors: Brinton
authors: Deborah
authors: D
authors: Glueck
authors: Tessa L
authors: TL
authors: Crume
authors: Jacob E
authors: JE
authors: Friedman
authors: Dana
authors: D
authors: Dabelea
mesh_terms: D050154:Adiposity / Q000502:physiology*; D000328:Adult; D001724:Birth Weight / Q000502:physiology; D001786:Blood Glucose / Q000378:metabolism*; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007333:Insulin Resistance / Q000502:physiology*; D008055:Lipids / Q000097:blood; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena / Q000502:physiology*; D050177:Overweight / Q000378:metabolism*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D008055:Lipids
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