title: Twenty-four-hour urine insulin as a measure of hyperinsulinaemia/insulin resistance before onset of pre-eclampsia and gestational hypertension.
abstract: OBJECTIVE
  To evaluate levels of 24-hour urine insulin excretion before the onset of pre-eclampsia and gestational hypertension.
  
  
  METHODS
  Nested case-control study within the Calcium for Preeclampsia Prevention (CPEP) study cohort.
  
  
  METHODS
  Five university medical centres in the United States.
  
  
  METHODS
  Cases had developed pre-eclampsia (n= 70) or gestational hypertension (n= 142) in the absence of gestational diabetes. Controls (n= 429) had remained normotensive without gestational diabetes.
  
  
  METHODS
  Subjects were required to have had an adequate baseline 24-hour urine collection prior to CPEP enrolment at 13-21 weeks. Controls were matched to cases by enrolment site and specimen storage time, without regard to gestational age or CPEP treatment. Adjusted mean 24-hour urine insulin excretion was, however, calculated using analysis of covariance, with adjustment models for pre-eclampsia considering body mass index, race and smoking status; and for gestational hypertension, gestational age at specimen collection, height, body mass index and smoking. Urine insulin was measured by radio-immunoassay.
  
  
  METHODS
  Twenty-four-hour urine insulin excretion.
  
  
  RESULTS
  Adjusted 24-hour urine insulin excretion at baseline (mean 17 weeks of gestation) was greater in women who developed pre-eclampsia than in normotensive controls (mean [SE]: 15.6 [1.5] vs 13.1 [1.2] x 10(3)microIU/24 hour, P= 0.06), but not in women who developed gestational hypertension (14.7 [0.9] vs 15.0 [0.6] x 10(3)microIU/24 hour, P= 0.79, in cases vs controls). Among women who developed pre-eclampsia, adjusted urine insulin excretion was greater than controls only in women with mild pre-eclampsia and not in severe pre-eclampsia (mild pre-eclampsia vs controls: 17.3 [2.0] vs 13.7 [1.6] x 10(3)microIU/24 hour, P= 0.04; severe pre-eclampsia vs controls: 12.3 [2.2] vs 11.5 [1.2], P= 0.69).
  
  
  CONCLUSIONS
  The data suggest that early hyperinsulinaemia, a marker of insulin resistance, may predispose to mild pre-eclampsia.
authors.affiliation: Department of Obstetrics and Gynecology, Cleveland Clinic Foundation, Cleveland, Ohio, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Emery
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Levine
authors.forename: Cong
authors.initials: C
authors.lastname: Qian
authors.forename: Marian G
authors.initials: MG
authors.lastname: Ewell
authors.forename: Lucinda J
authors.initials: LJ
authors.lastname: England
authors.forename: Kai F
authors.initials: KF
authors.lastname: Yu
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Catalano
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006946:Hyperinsulinism / Q000175:diagnosis*; D046110:Hypertension, Pregnancy-Induced / Q000652:urine*; D007328:Insulin / Q000652:urine*; D007333:Insulin Resistance / Q000502:physiology*; D011225:Pre-Eclampsia / Q000652:urine*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis*
chemical_list: D007328:Insulin