Objective: To examine the relationship between erythrocyte docosahexaenoic acid (DHA) and inflammatory biomarkers in the 35th-37th week of gestation in healthy overweight/obese pregnant women 18-40 years of age of different races/ethnicities (African American, Hispanic, White), following 10 weeks of supplementation with or 530 mg corn/soybean oil blend.
Design: Randomized, double-blinded, placebo-controlled trial.
Subjects: 107 healthy gravidas between the ages of 18-40 years with a singleton pregnancy, body mass index (BMI) >25, and who completed all study visits.
Methods: Pregnant women were randomized into either the DHA or control group. Subjects were given either 800 mg purified algae docosahexaenoic or 530 mg corn/soybean oil blend beginning at the 26th week until the 35th-37th week of their pregnancy. Venous blood was collected during three study visits and analyzed for erythrocyte DHA, adiponectin, IL-6 and TNF-alpha. Outcome variables were assessed as the differences in the absolute measurement (values) and percent change (%) between baseline and study end measurements. Mean values are reported for normally distributed data and median values with interquartile ratios were reported for skewed data. One-way ANOVA was used to compare means by study group. The Kruska-Wallis Test was used as a non-parametric alternative to a one-way ANOVA. Two-way ANOVA was used to identify effects between inflammatory biomarkers (TNF-alpha, IL-6, adiponectin), and ethnicity between study groups.
Results: Women supplemented with DHA had significantly higher erythrocyte DHA as compared to the control group. There was a significant interaction between the study group and ethnic background on change in erythrocyte DHA, and blood levels of TNF-alpha (p<0.03, p<0.05 respectively). Hispanic and White women had an increase and African-American women a decrease in erythrocyte DHA following supplementation. In the control group, the African-American and White women had a slight increase in TNF-alpha (0.92 pg/ml, 1.2 pg/ml, respectively) and the Hispanic women had a slight decrease (-0.36). In the DHA group, all women had less than a 0.25 pg/ml increase in TNF-alpha. When experimental groups were divided based on race/ethnicity, the median level of absolute change in blood levels of adiponectin, IL-6, and TNF-alpha were different between the three groups (p<0.05, p<0.01, p<0.001 respectively).
Conclusion: DHA supplementation has varying effects on inflammatory biomarkers in healthy overweight/obese pregnant women of different races/ethnicities. Ethnicity and DHA supplementation have interacting effects on both erythrocyte DHA and blood TNF-alpha levels. Modifying DHA supplementation based on race/ethnicity may lower inflammatory status in pregnancy and improve negative fetal outcomes.