Background: To examine the effects of 10 weeks of daily supplementation with algal oil (800 mg docosahexaenoic acid {DHA}) on maternal glucose metabolism during the third trimester in healthy, obese pregnant women.
Design: Randomized, double-blinded, placebo-controlled trial
Participants/Setting: Sixty healthy gravidas between the ages of 18-40 years who were English speaking with a singleton pregnancy, BMI >25-<60kg/m2 and who had complete data for analysis were included in this sample.
Intervention: Women were supplemented beginning at the 26th week until the 35th-37th week of their pregnancy.
Main Outcome Measures: Effect of docosahexaenoic acid supplementation on maternal insulin sensitivity.
Statistical Analysis Performed: Pearson or Spearman correlation coefficients were used to identify the strength and direction of the linear relationship between erythrocyte DHA and factors affecting maternal glucose metabolism (insulin, A1c, leptin, adiponectin, TNF-a, and IL- 6) and the indices of insulin sensitivity (HOMA-IR, ISI {comp}). One-way analysis of variance (ANOVA) was used to compare the mean differences in the outcome variables between the two groups. Statistical significance was set as a p value <0.05; trends (p> .05 and <.10) were also noted.
Results: The DHA group had higher erythrocyte DHA at the end of the study (p<.0001). No relationship was seen between glucose, insulin, A1c, leptin, adiponectin, IL-6 and erythrocyte DHA. There were no differences between groups in the indices of insulin sensitivity. There was a significant difference between mean values of TNF-a (p=.025) and the change in TNF-a (p=.03) between groups; 8.4% of the variance in TNF-a could be explained by erythrocyte DHA. There was no relationship between the change in factors that affect maternal glucose metabolism and the change in erythrocyte DHA after supplementation.
Conclusion: DHA supplementation decreased plasma TNF-a concentrations in the third trimester of pregnancy, but did not affect insulin sensitivity or other markers of glucose metabolism. Further research is needed to see if this improvement in TNF-a could reduce the risk of fetal overgrowth in healthy, obese, pregnant women.