Isoflavone soy protein supplementation and atherosclerosis progression in healthy postmenopausal women: a randomized controlled trial
Howard N Hodis, Wendy J Mack, Naoko Kono, Stanley P Azen, Donna Shoupe, Juliana Hwang-Levine, Diana Petitti, Lora Whitfield-Maxwell, Mingzhu Yan, Adrian A Franke, Robert H Selzer, Women's Isoflavone Soy Health Research Group, Howard N Hodis, Martha Charlson, Irma Flores, Martha Huerta, Thelma LaBree, Sonia Lavender, Violetta McElreath, Janie Teran, Liny Zurbrugg, Philip Zurbrugg, Robert H Selzer, Mei Feng, Yanjie Li, Lora Whitfield-Maxwell, Ming Yan, Wendy J Mack, Stanley P Azen, Farzana Choudhury, Carlos Carballo, Chun Ju-Chien, Laurie Dustin, Adrian Herbert, Michael Hutchinson, Naoko Kono, George Martinez, Nitya Mathew, Olga Morales, Connie Wu, Mingzhu Xiang, Juliana Hwang-Levine, Gail Izumi, Arletta Ramirez, Luci Rodriguez, Donna Shoupe, Victor W Henderson, Carol A McCleary, Jan A St John, Robert Rude, Livia Y Wei, Anna H Wu, Chiu-chen Tseng, Giske Ursin, Adrian A Franke, Sandra M Hebshi, Ian Pagano, Meir Stampfer, Ronald M Krauss, J Christopher Gallagher, Josh Berman, Catherine Stoney, Shan S Wong, Lisa Begg, Rebecca B Costello, Howard N Hodis, Wendy J Mack, Naoko Kono, Stanley P Azen, Donna Shoupe, Juliana Hwang-Levine, Diana Petitti, Lora Whitfield-Maxwell, Mingzhu Yan, Adrian A Franke, Robert H Selzer, Women's Isoflavone Soy Health Research Group, Howard N Hodis, Martha Charlson, Irma Flores, Martha Huerta, Thelma LaBree, Sonia Lavender, Violetta McElreath, Janie Teran, Liny Zurbrugg, Philip Zurbrugg, Robert H Selzer, Mei Feng, Yanjie Li, Lora Whitfield-Maxwell, Ming Yan, Wendy J Mack, Stanley P Azen, Farzana Choudhury, Carlos Carballo, Chun Ju-Chien, Laurie Dustin, Adrian Herbert, Michael Hutchinson, Naoko Kono, George Martinez, Nitya Mathew, Olga Morales, Connie Wu, Mingzhu Xiang, Juliana Hwang-Levine, Gail Izumi, Arletta Ramirez, Luci Rodriguez, Donna Shoupe, Victor W Henderson, Carol A McCleary, Jan A St John, Robert Rude, Livia Y Wei, Anna H Wu, Chiu-chen Tseng, Giske Ursin, Adrian A Franke, Sandra M Hebshi, Ian Pagano, Meir Stampfer, Ronald M Krauss, J Christopher Gallagher, Josh Berman, Catherine Stoney, Shan S Wong, Lisa Begg, Rebecca B Costello
Abstract
Background and purpose: Although epidemiological and experimental studies suggest that dietary intake of soy may be cardioprotective, use of isoflavone soy protein (ISP) supplementation as a primary preventive therapy remains unexplored. We determined whether ISP reduces subclinical atherosclerosis assessed as carotid artery intima-media thickness progression.
Methods: In a double-blind, placebo-controlled trial, 350 postmenopausal women 45 to 92 years of age without diabetes and cardiovascular disease were randomized to 2 evenly divided daily doses of 25 g soy protein containing 91 mg aglycon isoflavone equivalents or placebo for 2.7 years.
Results: Overall, mean (95% CI) carotid artery intima-media thickness progression rate was 4.77 (3.39-6.16) μm/year in the ISP group and 5.68 (4.30-7.06) μm/year in the placebo group. Although carotid artery intima-media thickness progression was reduced on average by 16% in the ISP group relative to the placebo group, this treatment effect was not statistically significant (P=0.36). Among the subgroup of women who were randomized within 5 years of menopause, ISP participants had on average a 68% lower carotid artery intima-media thickness progression rate than placebo participants 2.16 (-1.10 to 5.43) versus 6.79 (3.56-10.01) μm/year (P=0.05). ISP supplementation had a null effect on women who were >5 years beyond menopause when randomized. There were no major adverse events from ISP supplementation.
Conclusions: ISP supplementation did not significantly reduce subclinical atherosclerosis progression in postmenopausal women. Subgroup analysis suggests that ISP supplementation may reduce subclinical atherosclerosis in healthy young (median age, 53 years) women at low-risk for cardiovascular disease who were <5 years postmenopausal. These first trial results of their kind warrant further investigation.
Trial registration: ClinicalTrials.gov NCT00118846.
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Source: PubMed