title: Effect of Soy in Men With Type 2 Diabetes Mellitus and Subclinical Hypogonadism: A Randomized Controlled Study.
abstract: BACKGROUND
  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 glycemia and cardiovascular risk markers.
  
  
  METHODS
  This was a randomized double-blind parallel study.
  
  
  METHODS
  This study occurred in a secondary care setting in United Kingdom.
  
  
  METHODS
  Two hundred men with T2DM and a total testosterone level ≤12 nmol/L were included.
  
  
  METHODS
  Fifteen grams of soy protein with 66 mg of isoflavones (SPI) or 15 g soy protein alone without isoflavones (SP) daily as snack bars for 3 months were administered.
  
  
  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 thyrotropin (TSH) and reduction in free thyroxine (fT4; P < 0.01) after SPI supplementation. Glycemic control improved with a significant reduction in hemoglobin A1c (-4.19 [7.29] mmol/mol, P < 0.01) and homeostasis model of assessment - insulin resistance after SPI. Cardiovascular risk improved with a reduction in triglycerides, C-reactive protein, and diastolic blood pressure (DBP; P < 0.05) with SPI vs SP supplementation. There was a 6% improvement in 10-year coronary heart disease risk after 3 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 substantial improvement in glycaemia and cardiovascular risk markers with SPI compared with SP alone over 3 months. There was also a substantial increase in TSH and a reduction in fT4.
authors: Academic Diabetes, Endocrinology and Metabolism, Hull York Medical School, University of Hull, Hull, HU3 2 JZ, United Kingdom.
authors: Thozhukat
authors: T
authors: Sathyapalan
authors: Hull York Medical School, University of Hull, Hull, HU6 7RX, United Kingdom.
authors: Alan S
authors: AS
authors: Rigby
authors: Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.
authors: Shalender
authors: S
authors: Bhasin
authors: European Food Safety Authority, Parma, Italy.
authors: Natalie J
authors: NJ
authors: Thatcher
authors: Department of Pathology, Sidra Medical and Research Center, Doha, Qatar; and.
authors: Eric S
authors: ES
authors: Kilpatrick
authors: Weill Cornell Medical College Qatar, Education City, Doha, 24144, Qatar.
authors: Stephen L
authors: SL
authors: Atkin
mesh_terms: D000368:Aged; D000886:Anthropometry / Q000379:methods; D002318:Cardiovascular Diseases / Q000209:etiology / Q000517:prevention & control; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000188:drug therapy*; D004044:Dietary Proteins / Q000008:administration & dosage*; D004311:Double-Blind Method; D006801:Humans; D006943:Hyperglycemia / Q000188:drug therapy / Q000209:etiology; D007006:Hypogonadism / Q000097:blood*; D007529:Isoflavones / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D048789:Phytoestrogens / Q000097:blood; D030262:Soybean Proteins / Q000008:administration & dosage*; D013739:Testosterone / Q000097:blood
chemical_list: D004044:Dietary Proteins; D007529:Isoflavones; D048789:Phytoestrogens; D030262:Soybean Proteins; D013739:Testosterone; C065753:isoflavanone