Positive Health Online

Abstract

CHAMBERS and colleagues, National Heart and Lung Institute, Imperial College School of Medicine, Hammersmith Hospital, London, UK, J.kooner@ic.ac.uk investigated whether endothelial function is impaired in nonpregnant women with previous preeclampsia and whether endothelial dysfunction is mediated by oxidative stress.

Background

Preeclampsia is thought to result from the release of placental factors that damage the maternal vascular endothelium. Most studies, however, have been conducted during pregnancy, so it has not been possible to separate maternal from placental mechanisms underlying the endothelial dysfunction.

Methodology

A case-control study was conducted at 3 hospital maternity units in London, UK between July 1997 and June 2000 and involved 113 women with previous preeclampsia (n=78 with a single episode; n=35 with recurrent episodes) and 48 women with previous uncomplicated pregnancies. All were at least 3 months (median, 3 years) postpartum. The main outcome measures were brachial artery flow-mediated (endothelium-dependent) and glycerol trinitrate-induced (endothelium-independent) dilatation. These measures were compared between previously preeclamptic women and controls, and were repeated in 15 cases and 15 controls after administration of 1 gram ascorbic acid (vitamin C) intravenously.

Results

Mean flow-mediated dilatation was lower in women with previous preeclampsia (recurrent group, 0.9%; single-episode group, 2.7%; controls, 4.7%; p<0.001). Glycerol trinitrate-induced dilatation was similar in the 3 groups (19.5%, 21.0% and 21.0% respectively). Impaired flow-mediated dilatation in previously preeclamptic women was not accounted for by recognized vascular risk factors. Ascorbic acid increased flow-mediated dilatation in previously preeclamptic women (from 2.6% at baseline to 5.6%; p=0.001), but not in controls (baseline, 6.2% versus 6.7% after ascorbic acid).

Conclusion

The results indicate that endothelial function is impaired in nonpregnant women with previous preeclampsia, is not explained by established maternal risk factors, but is reversed by administration of the antioxidant ascorbic acid.

References

Chambers JC et al. Association of maternal endothelial dysfunction with preeclampsia. Journal of the American Medical Association (JAMA) 285 (12): 1607-12. Mar 2001.

Comment

This is a highly interesting finding. Positive Health will be publishing an article in Issue 69 about Intravenous Vitamin C Therapy by Stephen Levine Ph.D.