title: Relation between insulin kinetics and insulin sensitivity in pregnancy.
abstract: BACKGROUND
  Different time-concentration profiles of plasma insulin following insulin modification of a frequently sampled intravenous glucose-tolerance-test (FSIVGTT) were observed in a study investigating maternal metabolism and fetal macrosomia. We aimed to investigate whether these differences were related to the volume of distribution of insulin, insulin clearance, or both.
  
  
  METHODS
  Forty-four women were studied between 33 and 35 weeks' gestation using an insulin-modified FSIVGTT. Specific insulin was assayed with an enzyme-linked immunosorbent assay. Insulin sensitivity was calculated using the minimal model and the homeostasis model assessment (HOMA). The volume of distribution and clearance of insulin were calculated from measurements between 2 and 155 min after insulin modification using a one-compartment model.
  
  
  RESULTS
  In accordance with the method for deriving the volume of distribution, there was a significant negative correlation between the increment in insulin concentration and the volume of distribution (rho=-0.92, P<0.0001). The insulin increment was also related negatively to the clearance of insulin (rho=-0.88, P<0.0001). There was a significant correlation between the volume of distribution and both the insulin sensitivity index (rho=0.56, P<0.0001) and HOMA-%S (rho=0.30, P=0.048), and between the clearance of insulin and both the insulin sensitivity index (rho=0.83, P<0.0001)) and HOMA-%S (rho=0.34, P=0.025).
  
  
  CONCLUSIONS
  The different time-concentration profiles of plasma insulin resulted from differences in the volume of distribution and clearance of insulin. There was a correlation between insulin kinetics and the insulin sensitivity index. Further research is required to investigate possible mechanisms by which insulin kinetics may be related to insulin sensitivity.
authors.affiliation: Section of Endrocrinology and Metabolic Medicine, Imperial College London, St Mary's Campus, London, UK.
authors.forename: M C
authors.initials: MC
authors.lastname: Jolly
authors.forename: R
authors.initials: R
authors.lastname: Hovorka
authors.forename: I
authors.initials: I
authors.lastname: Godsland
authors.forename: R
authors.initials: R
authors.lastname: Amin
authors.forename: N
authors.initials: N
authors.lastname: Lawrence
authors.forename: V
authors.initials: V
authors.lastname: Anyaoku
authors.forename: D
authors.initials: D
authors.lastname: Johnston
authors.forename: S
authors.initials: S
authors.lastname: Robinson
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D005951:Glucose Tolerance Test / Q000379:methods; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance / Q000502:physiology*; D011247:Pregnancy / Q000502:physiology*; D012044:Regression Analysis
chemical_list: D007328:Insulin