Vivianne de S. Rocha

Association between magnesium status, oxidative stress and inflammation in preeclampsia: A case-control study.

BACKGROUND & AIMS Preeclampsia is responsible for more than one-third of all maternal deaths in Brazil. The objectives of the present study were to evaluate magnesium status and its association with oxidative stress and inflammation in preeclamptic women, and to identify the predictor variables of the disorder. METHODS The study population consisted of 36 women divided into preeclamptic (n = 18) and control groups (n = 18). The preeclamptic group included women (≥20 weeks of pregnancy) with arterial pressure ≥ 140/90 mmHg and proteinuria >0.3 g/24 h, while the control group comprised pregnant women with no clinical/obstetric complications. Magnesium intake was assessed via a food frequency questionnaire validated for pregnant women in Brazil. Plasma, erythrocyte and urinary magnesium levels were determined by flame atomic absorption spectroscopy, while oxidative stress and inflammatory markers were assessed using standard protocols. Logistic regression analysis was used to identify the predictors of preeclampsia. RESULTS Preeclamptic and control groups were similar with respect to magnesium intake and urinary excretion, while plasma and erythrocyte magnesium concentrations were higher in the former group. Plasma magnesium was positively correlated with catalase and glutathione peroxidase activities and with concentrations of interleukin-6 and tumor necrosis factor alpha. Regression analysis showed that plasma magnesium and urinary 8-isoprostane were associated with preeclampsia. CONCLUSION Magnesium status appears to result from homeostatic imbalance and physiological alterations typical of preeclampsia. Increased plasma magnesium and decreased urinary 8-isoprostane were considered predictors of preeclampsia.

Calcium and magnesium status is not impaired in pregnant women

Deficiencies in calcium (Ca) and magnesium (Mg) are associated with various complications during pregnancy. To test the hypothesis that the status of these minerals is inadequate in pregnancy, a cross-sectional study was conducted of the dietary intake and status of Ca and Mg in pregnant women (n = 50) attending a general public university hospital in Brazil. Dietary intake was assessed from 4-day food records; levels of plasma Mg, erythrocyte Mg, and urinary Ca and Mg excretion were determined by flame atomic absorption spectroscopy; and type I collagen C-telopeptides were evaluated by enzyme-linked immunosorbent assay. Probabilities of inadequate Ca and Mg intake were exhibited by 58 and 98% of the study population, respectively. The mean levels of urinary Ca and Mg excretion were 8.55 and 3.77 mmol/L, respectively. Plasma C-telopeptides, plasma Mg, and erythrocyte Mg were within normal levels. Multiple linear regression analysis revealed positive relationships among urinary Ca excretion, Ca intake (P = .002) and urinary Mg excretion (P < .001) and between erythrocyte Mg and Mg intake (P = .023). It is concluded that the Ca and Mg status of participants was adequate even though the intake of Ca and Mg was lower than the recommended level.

Increased serum iron in preeclamptic women is likely due to low hepcidin levels

The role of hepcidin in iron homeostasis in preeclamptic pregnant women is unclear. To test the hypothesis that increased serum iron in women diagnosed with preeclampsia results from decreased production of hepcidin, we performed an observational case-control study in which serum hepcidin concentration, dietary iron intake, hematological indices, iron status, liver function, and inflammatory markers in 18 preeclamptic women and 18 healthy normotensive pregnant women of similar age range were evaluated. Iron intake was established via a food frequency questionnaire, whereas hematological indices, iron status, liver function, and inflammatory markers were assessed using standard protocols. Hematocrit was significantly higher (P = .031) in the preeclamptic group compared with the control, whereas erythropoietin level was significantly lower (P = .003). The pronounced inflammatory status of preeclamptic women was confirmed by significantly higher concentrations of interleukin-6 (P = .001), tumor necrosis factor-α (P < .001), and ferritin (P < .001). Nonetheless, the preeclamptic group exhibited significantly higher serum iron (P = .012) and transferrin saturation (P = .006), and these alterations were accompanied by lower hepcidin levels (P = .047). No significant correlations between hepcidin concentration and iron status parameters were observed in either group. However, a positive and significant correlation between hepcidin concentration and C-reactive protein was observed in the preeclamptic group (r = 0.474; P = .047). We conclude that high serum iron in preeclamptic women is likely caused by low production of hepcidin, thus supporting the hypothesis originally stated.