Leukocyte selenium, zinc, and copper concentrations in preeclamptic and normotensive pregnant women

Preeclampsia is an important cause of maternal and perinatal mortality worl dwide. The etiology of this relatively common medical complication of pregn ancy, however, remains unknown. We studied the relationship between materna l leukocyte selenium, zinc, and copper concentrations and the risk of preec lampsia in a large hospital-based case-control study. One hundred seventy-o ne women with proteinuric pregnancy-induced hypertension (with or without s eizures) comprised the case group. Controls were 184 normotensive pregnant women. Leukocytes were separated from blood samples collected during the pa tients' postpartum labor and delivery admission. Leukocyte concentrations f or the three cations were measured by inductively coupled plasma-mass spect rometry (ICP-MS). Concentrations for each cation were reported as microgram s per gram of total protein. Women with preeclampsia had significantly high er median leukocyte selenium concentrations than normotensive controls (3.2 3 vs 2.80 mu g/g total protein, p < 0.0001). Median leukocyte zinc concentr ations were 31% higher in preeclamptics as compared with controls (179.15 v s 136.44 mu g/g total protein, p < 0.0001). Although median leukocyte coppe r concentrations were slightly higher for cases than controls, this differe nce did not reach statistical significance (17.72 vs 17.00 mu g/g total pro tein, p = 0.468). There was evidence of a linear increase in risk of preecl ampsia with increasing concentrations of selenium and zinc. The relative ri sk for preeclampsia was 3.38 (adjusted odds ratio [OR] = 3.38, 95% confiden ce interval [CI] = 1.53-7.54) among women in the highest quartile of the co ntrol selenium distribution compared with women in the lowest quartile. The corresponding relative risk and 95% CI for preeclampsia was 5.30 (2.45-11. 44) for women in the highest quartile of the control zinc distribution comp ared with women in the lowest quartile. There was no clear pattern of a lin ear trend in risk with increasing concentration of leukocyte copper concent rations (adjusted for Linear trend in risk = 0.299). Our results are consis tent with some previous reports. Prospective studies are needed to determin e whether observed alterations in selenium and zinc concentrations precede preeclampsia or whether the differences may be attributed to preeclampsia-r elated alterations in maternal and fetal-placental trace metal metabolism.