High muscle mass in Oregon women is associated with decreased antioxidant expression in the term placenta

Abstract

ObjectivePlacental oxidative stress is an imbalance between antioxidants and reactive oxygen species and is known to compromise fetal growth. We hypothesized that high maternal muscle mass and body mass index (BMI) in early pregnancy will lead to suppressed expression of placental antioxidant systems.MethodsWomen were categorized into groups based upon arm muscle area (AMA) [low: 20.1 ± 3.4 and high: 71.3 ± 16.2 cm2] and BMI [low: 19.3 ± 1.4 and high: 38.4 ± 2.5 kg/m2]. Term placental antioxidant gene expression, specifically catalase, superoxide dismutase (SOD) 1 and 2, and glutathione peroxidase (GPX) 1 and 4, was quantified by QPCR. 8‐isoprostane, a marker of oxidized lipid, was measured in maternal and fetal plasma.ResultsSOD2 protein and GPX1 mRNA levels were decreased (P<0.05) in women with high AMA. Antioxidant levels were not changed in placentas of women with high BMI. 8‐isoprostane increased with maternal BMI (R= 0.51, P<0.05) but not AMA (R=0.36), while fetal levels showed no association with maternal body type.Conclusionsa) Antioxidant expression was depressed in high AMA mothers as hypothesized without increased 8‐isoprostane. b) Contrary to the hypothesis, high BMI women had a different response. Placental antioxidant levels were unchanged while oxidative stress was increased in these mothers. Supported by the Collins Medical Trust, Northwest Health Foundation, Holtzman Foundation.