The effect of high dietary n-3 fatty acid supplementation on angiotensin II pressor response in human pregnancy

OBJECTIVE: Our purpose was to evaluate the effects of n-3 fatty acid supplementation on vascular reactivity as measured by the angiotensin II sensitivity test. STUDY DESIGN: Ten subjects with uneventful pregnancies, who were free of any chronic medical illnesses, between 24 and 34 weeksʹ gestation participated. Each subject was provided with OMEGA-3 700 softgel capsules and instructed to take three tablets three times daily (approximately 3.6 gm of eicosapentaenoic acid). The angiotensin II sensitivity test was performed before and 28 days after supplementation. Compliance was assessed by analysis of computerized pill bottles. Statistical analyses of the data were performed with a paired t test for evenly distributed continuous data. A sample size of eight patients was required to detect a difference in effective pressor dose of ≥10 ng/kg/min between the presupplement and postsupplement results, assuming an α of 0.05 and a β of 0.20 (80% power). RESULTS: The effective pressor dose before treatment (13.6 ± 6.3 ng/kg/min) (mean ± SD) was significantly less (p = 0.001) than after supplementation (35.8 ± 15.9 ng/kg/min). CONCLUSIONS: High-dose n-3 fatty acid supplementation resulted in an enhancement of the pregnancy-acquired refractoriness to angiotensin II. (Am J Obstet Gynecol 1996;175:688-91.)