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.

Abstract

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.

Citation

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. https://doi.org/10.1210/jc.2016-2875

• 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
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 102
• Issue: 2
• Pages: 425-433
• DOI: https://doi.org/10.1210/jc.2016-2875
• Keywords: Soybean, Diabetes mellitus, Hypogonadism
• Public URL: https://hull-repository.worktribe.com/output/445224
• Publisher URL: http://press.endocrine.org/doi/10.1210/jc.2016-2875
• Additional Information: Copy of article first published in: Journal of clinical endocrinology and metabolism, 2017, v.102, issue 2.
• Contract Date: Nov 17, 2016