Skip to main content

Research Repository

Advanced Search

The effect of soy phytoestrogen supplementation on thyroid status and cardiovascular risk markers in patients with subclinical hypothyroidism: A randomized, double-blind, crossover study

Sathyapalan, Thozhukat; Manuchehri, Alireza M.; Thatcher, Natalie J.; Rigby, Alan S.; Chapman, Tom; Kilpatrick, Eric S.; Atkin, Stephen L.

Authors

Alireza M. Manuchehri

Natalie J. Thatcher

Tom Chapman

Eric S. Kilpatrick

Stephen L. Atkin



Abstract

Context: There is concern whether soy phytoestrogens may affect thyroid function. If true, soy phytoestrogens may be expected to have a greater impact in subjects with subclinical hypothyroidism. Objective: The primary aim was to determine the effect of soy phytoestrogen supplementation on thyroid function, with a secondary aim of assessing the effects on cardiovascular risk indices in patients with subclinical hypothyroidism. Design and Setting: We conducted a randomized, double-blind, crossover study in a tertiary care setting. Participants: Sixty patients with subclinical hypothyroidism participated in the study. Intervention: Patients were randomly assigned to either low-dose phytoestrogen (30 g soy protein with 2 mg phytoestrogens, representative of a Western diet) or high-dose phytoestrogen (30 g soy protein with 16 mg phytoestrogens, representative of a vegetarian diet) supplementation for 8 wk, then crossed over after an 8-wk washout period. Main Outcome Measures: The primary outcome was progression to overt hypothyroidism, with secondary outcome measures of blood pressure, insulin resistance, lipids, and highly sensitive C-reactive protein (hsCRP). Results: Six female patients in the study progressed into overt hypothyroidism with a standardized rate ratio of 3.6 (95% confidence interval, 1.9, 6.2) after 16-mg phytoestrogen supplementation. Both systolic and diastolic blood pressure decreased with 16 mg phytoestrogens, whereas systolic pressure alone decreased with 2 mg phytoestrogens. Insulin resistance (homeostasis model assessment of insulin resistance, 3.5 ± 0.09 vs. 2.6 ± 0.08; P < 0.02) and hsCRP (4.9 ± 0.04 vs. 3.9 ± 0.03; P < 0.01) decreased with 16 mg phytoestrogens. Lipid profile remained unchanged. Conclusion: There is a 3-fold increased risk of developing overt hypothyroidism with dietary supplementation of 16 mg soy phytoestrogens with subclinical hypothyroidism. However, 16-mg soy phytoestrogen supplementation significantly reduces the insulin resistance, hsCRP, and blood pressure in these patients. Copyright © 2011 by The Endocrine Society.

Citation

Sathyapalan, T., Manuchehri, A. M., Thatcher, N. J., Rigby, A. S., Chapman, T., Kilpatrick, E. S., & Atkin, S. L. (2011). The effect of soy phytoestrogen supplementation on thyroid status and cardiovascular risk markers in patients with subclinical hypothyroidism: A randomized, double-blind, crossover study. Journal of Clinical Endocrinology and Metabolism, 96(5), 1442-1449. https://doi.org/10.1210/jc.2010-2255

Journal Article Type Article
Acceptance Date Jan 24, 2011
Publication Date May 1, 2011
Deposit Date Nov 13, 2014
Publicly Available Date Mar 29, 2024
Journal Journal of clinical endocrinology & metabolism
Print ISSN 0021-972x
Electronic ISSN 0021-972X
Publisher Oxford University Press
Peer Reviewed Not Peer Reviewed
Volume 96
Issue 5
Pages 1442-1449
DOI https://doi.org/10.1210/jc.2010-2255
Keywords Clinical Biochemistry; Biochemistry; Endocrinology, Diabetes and Metabolism; Endocrinology; Biochemistry, medical
Public URL https://hull-repository.worktribe.com/output/463243
Publisher URL http://press.endocrine.org/doi/abs/10.1210/jc.2010-2255
Additional Information Copy of article first published in Journal of clinical endocrinology & metabolism

Files





You might also like



Downloadable Citations