Selenium and Preeclampsia (Research)

Research Summary

Rayman, 2003    Human   

Toenail selenium levels were measured in pregnant women with preeclampsia and in healthy pregnant women.    Women in the lowest tertile of toenail selenium had a 4.4-fold increased risk of preeclampsia.  Women with preeclampsia with lower toenail selenium levels had more severe preeclampsia than women with preecelampsia with higher toenail selenium levels.Authors conclude that a small increase in selenium intake might help to prevent preeclampsia.

Vanderlelie, 2004    Animal: rats   

Rats were fed diets containing no selenium, average selenium or high selenium, for 4 weeks prior to and following conception.    Rats in the selenium-deficient group had significantly higher systolic blood pressure (preeclampsia) than rats in the normal selenium and high selenium groups.

Peer-Reviewed Professional Journals

·    Rayman, M. P., et al.  Low selenium status is associated with the occurrence of the pregnancy disease preeclampsia in women from the United Kingdom.  Am J Obstet Gynecol.  189(5):1343-1349, 2003.

School of Biomedical and Molecular Sciences, University of Surrey, United Kingdom.

Because the trace element selenium behaves as an antioxidant and peroxynitrite scavenger when incorporated into selenoproteins, the objective of this study was to determine whether low selenium status was associated with a greater risk of occurrence of preeclampsia.  53 preeclamptic patients and 53 matched pregnant controls at the John Radcliffe Hospital, Oxford, gave clippings of their toenails (laid down from 3-12 months previously) for selenium determination by neutron activation analysis.  Clinical characteristics of the women and their infants were recorded.  Statistical analysis was by Wilcoxon signed rank test and odds ratios were calculated by the ratio of discordant pairs.  Median toenail selenium concentrations in the preeclamptic subjects were significantly lower than in their matched controls (P=.001).  Being in the bottom tertile of toenail selenium was associated with a 4.4-fold (95% CI 1.6-14.9) greater incidence of the condition.  Within the preeclamptic group, lower selenium status was significantly associated (P=.029) with more severe expression of disease, as measured by delivery before 32 weeks.   In the light of the reduction in selenium status in a number of European countries in recent years, this study raises the question of whether a small increase in selenium intake might help prevent preeclampsia in susceptible women.

·    Vanderlelie, J., et al.  Selenium deficiency as a model of experimental pre-eclampsia in rats.  Reproduction.  128(5):635-641, 2004.

School of Health Science, Griffith University Gold Coast Campus, Southport, QLD, Australia.

Epidemiological studies and in vitro analysis demonstrate correlations between selenium status and human pre-eclampsia (PET).  Selenium is an essential component in the anti-
oxidant proteins glutathione peroxidase and thioredoxin reductase, which are produced in lower amounts in pre-eclamptic placenta.  This study examined the effect of modulating dietary selenium content in pregnant rats.  Rats were fed diets containing no selenium, 239 g/kg selenium or 1000 g/kg selenium, four weeks prior to and following conception.  Significant pregnancy-specific increases in systolic blood pressure (116.4 +/- 5.2 mmHg vs 108 +/- 6.8 mmHg vs 111.4 +/- 4.7 mmHg) and proteinuria (9.68 +/- 2.12 g/ml vs 5.93 +/- 1.59 g/ml vs 4.43 +/- 0.96 g/ml) were demonstrated in animals fed a selenium free-diet when compared with normal or high selenium diets.  Placental weight and pup number were not affected by selenium deprivation, however a significant decrease in the pup weight was evident.  Selenium deprivation caused dose-dependent decreases in liver glutathione peroxidase (28.55 +/- 3.82 mmoles/min/mg vs 34.68 +/- 8.64 mmoles/min/mg) and thioredoxin reductase (2.37 +/- 1.25 U/mg vs 6.68 +/- 1.82 U/mg) activity, whereas superoxide dismutase activity remained constant.  Placental activity of these enzymes also decreased leading to oxidative stress as measured by increased lipid peroxides (17.92 +/- 1.78 moles/mg vs 8.30 +/- 5.52 moles/mg) and protein carbonyls in tissue extracts from selenium-free animals.  These results suggest that selenium deficiency in pregnant rats leads to symptoms similar to those seen in human PET and may provide an experimental model for studying this complex disease.