title: Longitudinal study of carbohydrate metabolism in healthy obese pregnant women.
abstract: OBJECTIVE
  To longitudinally characterize changes in insulin sensitivity in obese women during and after pregnancy.
  
  
  METHODS
  Six glucose-tolerant obese women underwent a 4-h euglycemic-hyperinsulinemic (500-600 pmol/l) clamping during the second (22.5 +/- 2 weeks [mean +/- SD]) and third trimester (36.8 +/- 0.9) of pregnancy and again 15.6 +/- 1.4 weeks after delivery. Rates of total body glucose turnover (with [6.6-2H2]glucose) and oxidation (with indirect calorimetry) were measured.
  
  
  RESULTS
  There were no significant changes with respect to the action of insulin on rates of glucose disappearance (GRd), carbohydrate oxidation, or endogenous glucose production (EGP), comparing the second trimester of pregnancy with the nonpregnant (postpartum) state. The third trimester, however, was characterized 1) by reductions in insulin-stimulated GRd (-28%, P < 0.05, compared with the second trimester and -40%, P < 0.05, compared with postpartum); 2) by even larger reductions in insulin-stimulated carbohydrate oxidation (-46%, P < 0.05, compared with the second trimester and -54%, P < 0.02, compared with postpartum); and 3) by reduction of insulin suppression of EGP (-39% compared with -79% at the second trimester and -77% postpartum, P < 0.01).
  
  
  CONCLUSIONS
  Glucose-tolerant obese women developed peripheral was well as hepatic insulin resistance during the third trimester of pregnancy. These alterations were reversed after delivery and appeared to be adaptive mechanisms to cope with the increased demand for glucose of the growing fetus.
authors.affiliation: Department of Obstetrics/Gynecology, Temple University Hospital, Philadelphia, Pennsylvania 19140, USA.
authors.forename: E
authors.initials: E
authors.lastname: Sivan
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: C J
authors.initials: CJ
authors.lastname: Homko
authors.forename: E A
authors.initials: EA
authors.lastname: Reece
authors.forename: G
authors.initials: G
authors.lastname: Boden
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000328:Adult; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism*; D015309:Glucose Clamp Technique; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood / Q000378:metabolism; D008137:Longitudinal Studies; D009765:Obesity / Q000097:blood / Q000378:metabolism*; D010084:Oxidation-Reduction; D010928:Placental Lactogen / Q000097:blood; D049590:Postpartum Period / Q000097:blood / Q000378:metabolism*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000378:metabolism*; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D002241:Carbohydrates; D007328:Insulin; D010928:Placental Lactogen; D005947:Glucose; D006854:Hydrocortisone