Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2013
Publication Date: 12/31/2013
Citation: Shi, L., Harker-Ryan, H., Jones, E., Moore-Simas, T.A., Lichtenstein, A.H., Sun, Q., Hayman, L.L. 2013. Urinary isoflavone concentrations are inversely associated with lower cardiometabolic risk markers in pregnant U.S. women. Journal of Nutrition. 144(3):344-351. DOI:10.3945/JN.113.184069. Interpretive Summary: Some evidence suggests that compounds present in soybeans, commonly referred to as phytoestrogens, may have beneficial effects on risk factors for heart disease and blood glucose control in older women or those at high risk of heart disease. There is a lack of data for an effect of these components in soybeans (isoflavones) in pregnant women who have high hormone levels (estrogen) as well as high blood sugar and lipid levels. We analyzed data from 299 pregnant women who participated in a national survey of health and nutrition (National Health and Nutrition Examination Survey [NHANES)]. Statistical analyses were used to determine whether there was an association between urinary isoflavonoids excretion, an indicator of consumption of foods containing soybeans, and heart disease risk factors. Comparing women in the highest versus lowest quartiles of estimated soybean intake we observed a significant negative relationship between urinary isoflavone excretion and fasting blood sugar and insulin concentrations, a measure of insulin sensitivity and triglyceride concentrations, but not with other plasma lipids (total cholesterol, low density lipoprotein cholesterol and high-density lipoprotein cholesterol) concentrations. These data suggest there may be a benefit of consuming foods containing soybean for pregnant women.
Technical Abstract: Some evidence suggests that phytoestrogens such as soy-derived isoflavones may have beneficial effects on cardiovascular health and glycemic control. These data are mainly limited to postmenopausal women or individuals at elevated cardiometabolic risk. There is a lack of data for pregnant women who have elevated estrogen levels and physiologically altered glucose and lipid metabolism. We analyzed data from 299 pregnant women who participated in the National Health and Nutrition Examination Survey (NHANES) 2001-2008 surveys. Multivariable linear regression analyses were used to examine the association between urinary concentrations of isoflavonoids and cardiometabolic risk markers, adjusted for body mass index (BMI), pregnancy trimester, total energy intake, dietary intake of protein, fiber, and cholesterol, and demographic and lifestyle factors. Cardiometabolic risk markers were log-transformed and geometric means were calculated by quartiles of urinary concentrations of isoflavonoids. Comparing women in the highest versus lowest quartiles of total isoflavone concentrations we observed a significant, inverse association between total urinary isoflavone concentrations and fasting glucose concentrations (79 versus 88 mg/dL, P for trend equals 0.0009); insulin concentrations (8.2 versus 12.8 µU/mL, P for trend equals 0.03), HOMA-IR (1.6 versus 2.8, P for trend equals 0.01), and triglyceride (TG) concentrations (156 versus 185 mg/dL, P for trend equals 0.02) but not for total, low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) concentrations. The concentrations of individual isoflavonoids, daidzein, equol and O-desmethylangolensin (O-DMA), were inversely associated with some cardiometabolic risk markers, though no clear pattern emerged. These data suggest there may be a relationship between isoflavone intake and cardiometabolic risk markers in pregnant women.