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Effect of soy in men with type 2 diabetes mellitus and subclinical hypogonadism: a randomised controlled study

Sathyapalan, Thozhukat; Rigby, Alan S.; Bhasin, Shalender; Thatcher, Natalie J.; Kilpatrick, Eric S.; Atkin, Stephen L.


Thozhukat Sathyapalan

Alan S. Rigby

Shalender Bhasin

Natalie J. Thatcher

Eric S. Kilpatrick

Stephen L. Atkin


Context: Isoflavones found in soy products have a chemical structure similar to estrogen, leading to concerns of an adverse estrogenic effect in men, particularly in those with type 2 diabetes mellitus (T2DM) who have low testosterone levels due to hypogonadism. Objective: The primary outcome was change in total testosterone levels. The secondary outcomes were the changes in glycaemia and cardiovascular risk markers. Design: Randomised double blind parallel study. Setting: Secondary care setting in UK. Participants: 200 men with T2DM with a total testosterone level≤12nmol/L Intervention: 15g soy protein with 66mg of isoflavones (SPI) or 15g soy protein alone without isoflavones (SP) daily as snack bars for three months. Results: There was no change in either total testosterone or in absolute free testosterone levels with either SPI or SP. There was an increase in TSH and reduction in fT4 (p<0.01) after SPI supplementation. Glycaemic control improved with a significant reduction in HbA1c (-4.19(7.29)mmol/mol,p<0.01) and HOMA-IR after SPI. Cardiovascular risk improved with a reduction in triglycerides, CRP and diastolic BP (p<0.05) with SPI versus SP supplementation. There was 6% improvement in 10-year coronary heart disease risk after three months of SPI supplementation. Endothelial function improved with both SPI and SP supplementation (p<0.01) with an increased reactive hyperemia index that was greater for the SPI group (p<0.05). Conclusions: Testosterone levels were unchanged and there was a significant improvement in glycaemia and cardiovascular risk markers with SPI compared to SP alone over three months. There was significant increase in TSH and a reduction in fT4.


Sathyapalan, T., Rigby, A. S., Bhasin, S., Thatcher, N. J., Kilpatrick, E. S., & Atkin, S. L. (2017). Effect of soy in men with type 2 diabetes mellitus and subclinical hypogonadism: a randomised controlled study. Journal of Clinical Endocrinology and Metabolism, 102(2), (425-433). doi:10.1210/jc.2016-2875. ISSN 0021-972x

Journal Article Type Article
Acceptance Date Oct 25, 2016
Online Publication Date Oct 31, 2016
Publication Date Feb 1, 2017
Deposit Date Nov 17, 2016
Publicly Available Date Nov 17, 2016
Journal Journal of clinical endocrinology and metabolism
Print ISSN 0021-972x
Electronic ISSN 1945-7197
Publisher Oxford University Press (OUP)
Peer Reviewed Peer Reviewed
Volume 102
Issue 2
Pages 425-433
Keywords Soybean, Diabetes mellitus, Hypogonadism
Public URL
Publisher URL
Additional Information Copy of article first published in: Journal of clinical endocrinology and metabolism, 2017, v.102, issue 2.


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