Zinc, antioxidant enzymes in preeclampsia, and association with newborn outcome

The etiology of preeclampsia (PE) may be associated with the increased of production of reactive species and decreased antioxidant activity of enzymes. Inadequate intake of Zn can affect gestational health due to its biological functions, such as its role in the antioxidant defense system. The study aimed to assess the nutritional status of Zn and antioxidant enzymes in postpartum women and its correlation with neonatal outcomes.

A cross-sectional analytical study was carried out at a referral gynecology and obstetrics hospital. A total of 119 women (PE = 58, HP = 61) participated in the study. A quantitative food-frequency questionnaire was used to assess food consumption and further analyze the dietary Zn levels. Zinc levels in plasma and erythrocytes samples were analyzed by flame atomic absorption spectrometry, catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels were determined by UV-Vis spectrophotometry.

Plasma and dietary intake Zn results were considered adequate and without statistical difference between groups. SOD levels were significantly higher in the HP group (p = 0.011), and CAT levels were higher in the PE group (p = 0.050). There was a positive correlation between SOD activity in women with PE and the weight of their newborns (r = 0.336, p=0.021).

The results showed adequate Zn levels (consumption and serum levels) in the groups studied, although with a reduction of plasma Zn in the PE group compared to the PH group. Zinc in plasma fractions and erythrocytes are important markers for oxidative stress, in particular, plasma Zn seems to be related to the rapid response to preeclampsia. The activity of antioxidant enzymes was elevated in the groups studied. Better SOD activity improves birth weight in children of pregnant women with preeclampsia.