title: Low plasma volume coincides with sympathetic hyperactivity and reduced baroreflex sensitivity in formerly preeclamptic patients.
abstract: BACKGROUND
  Preeclampsia is associated with enhanced sympathetic activity as well as subnormal plasma volume. Meanwhile, in over 50% of these complicated pregnancies, the subnormal plasma volume has been found to persist for a prolonged period after pregnancy. The objective of this study is to test the hypothesis that in normotensive formerly-preeclamptic women, persistence of a subnormal plasma volume coincides with enhanced sympathetic activity and with it, an altered autonomic control of blood pressure.
  
  
  METHODS
  Forty-eight formerly-preeclamptic women participated in this study. After measurement of their plasma volume by iodine 125-albumin indicator dilution, they were subdivided into a group with a normal plasma volume (plasma volume > 48 ml/kg lean body mass) and a group with a subnormal plasma volume (< or = 48 ml/kg lean body mass). We performed spectral analysis on their beat-to-beat blood pressure and heart rate recordings and compared both groups using non-parametric tests.
  
  
  RESULTS
  Formerly-preeclamptic women with a subnormal plasma volume had a higher sympathetic activity (P = .001) and a lower baroreflex sensitivity (P = .04) than their counterparts with a normal plasma volume.
  
  
  CONCLUSIONS
  In normotensive formerly-preeclamptic women, a subnormal plasma volume coincides with a higher sympathetic activity in the blood pressure regulation and lower baroreflex sensitivity. Whether these alterations in the autonomic control mechanisms are a cause or effect of the subnormal plasma volume remains to be elucidated.
authors.affiliation: Department of Obstetrics and Gynecology, University Hospital Maastricht, Maastricht, The Netherlands. dorette.courtar@og.unimaas.nl
authors.forename: Dorette A
authors.initials: DA
authors.lastname: Courtar
authors.forename: Marc E A
authors.initials: ME
authors.lastname: Spaanderman
authors.forename: Robert
authors.initials: R
authors.lastname: Aardenburg
authors.forename: Ben J A
authors.initials: BJ
authors.lastname: Janssen
authors.forename: Louis L H
authors.initials: LL
authors.lastname: Peeters
mesh_terms: D000328:Adult; D017704:Baroreflex; D001794:Blood Pressure / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D010953:Plasma Volume; D011225:Pre-Eclampsia / Q000503:physiopathology*; D011247:Pregnancy; D012021:Reflex, Abnormal; D013564:Sympathetic Nervous System / Q000502:physiology*