Associations Between Maternal Tocopherol Levels and Pregnancy-Induced Blood Pressure Changes

Abstract

Objectives Vitamin E plays different roles in health based on its three isoforms: alpha (α)-tocopherol is anti-inflammatory, gamma (γ)-tocopherol is pro-inflammatory, delta (δ)-tocopherol remains unknown. As inflammation may promote hypertension, the objective of this study is to examine relationships between maternal serum tocopherol levels at time of delivery and pregnancy-related blood pressure (BP) changes. Hypothesis is that increased level of α-tocopherol has favorable effects and γ-tocopherol has adverse effects on maternal BP. Methods An IRB-approved cross-sectional study enrolled mother-infant dyads (n = 342) at time of delivery (Omaha, NE, USA) for collection of electronic health data and maternal blood. High-performance liquid chromatography analyzed serum tocopherol levels. Maternal BP values were collected from 1st and 3rd trimester clinic/hospital visits with changes calculated in systolic BP and mean arterial pressure (MAP = diastolic BP + 1/3(systolic BP – diastolic BP). Mothers were classified as hypertensive if: systolic BP ≥140, diastolic BP ≥ 90, or diagnosis of preeclampsia. Two-sample t-test and Pearson correlation coefficients compared relationships between serum tocopherol levels and BP data. P-value < 0.05 was significant. Results Mean maternal age was 28.5 years, majority (61.4%) Caucasian, 10.4% (n = 29) with hypertension. Mean serum levels: α-tocopherol 15,229 + 5849 mcg/L, γ-tocopherol 1642 + 868 mcg/L, δ-tocopherol 226 + 164 mcg/L, with α: γ ratio 11.5 + 8.7. Mean serum α-tocopherol level was higher in normotensive vs. hypertensive mothers (15,751 vs. 13,819 mcg/L; P = 0.06). Ratio of α: γ demonstrated an inverse correlation with change in maternal systolic BP (r = −0.128; P = 0.03). No other relationships were significant. Conclusions Increasing maternal α-tocopherol and α: γ ratio has favorable association with maintaining normal BP during pregnancy. More research is needed to specifically identify serum thresholds and tocopherol isoform ratios for favorably reducing risk of pregnancy-related hypertension. Funding Sources Department of Pediatrics and the Child Health Research Institute at the University of Nebraska Medical Center and Children's Hospital & Medical Center (Omaha, NE).