title: Low serum testosterone concentration in middle-aged men with type 2 diabetes.
abstract: Low concentrations of endogenous androgens have been linked with insulin resistance and atherosclerosis. Men with diabetes have been reported to have lower serum testosterone concentration than non-diabetic men; however, there has never been a large study. The aim of this study was to investigate if endogenous androgen concentration is certainly lower in a relatively large number of Japanese patients with type 2 diabetes compared with healthy men, and to identify what factors may be associated with low serum testosterone concentrations in men with type 2 diabetes. Serum free testosterone concentrations were measured in 524 healthy men and in 331 consecutive Japanese men with type 2 diabetes between 40 and 69 years old. In addition, we investigated the relationships between serum free testosterone concentration and luteinizing hormone (LH) concentration as well as major cardiovascular risk factors including age, blood pressure, plasma lipid concentration, glycemic control (HbA(1c)), and BMI. Serum free testosterone concentrations were lower in men with type 2 diabetes than in healthy men in the 40-49 years group (10.9 +/- 3.3 vs. 14.0 +/- 3.6 pg/ml, P<0.0001), in the 50-59 years group (10.4 +/- 3.2 vs. 12.1 +/- 2.9 pg/ml, P<0.0001), and in the 60-69 years group (9.5 +/- 2.6 vs. 10.5 +/- 2.9 pg/ml, P = 0.0104). A negative correlation was found between serum free testosterone and LH concentrations (r = -0.326, P<0.0001). In conclusion, serum free testosterone concentration is certainly lower in a relatively large number of Japanese patients with type 2 diabetes compared with healthy men with each decade of life between 40 and 69 years old.
authors.affiliation: Department of Endocrinology and Metabolism, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Fukui
authors.forename: Jintetsu
authors.initials: J
authors.lastname: Soh
authors.forename: Muhei
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kitagawa
authors.forename: Goji
authors.initials: G
authors.lastname: Hasegawa
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Tsuneharu
authors.initials: T
authors.lastname: Miki
authors.forename: Naoto
authors.initials: N
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002784:Cholesterol / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000097:blood; D003930:Diabetic Retinopathy / Q000097:blood; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D016014:Linear Models; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D013739:Testosterone / Q000097:blood*; D014280:Triglycerides / Q000097:blood
chemical_list: D002784:Cholesterol; D006442:Glycated Hemoglobin; D007986:Luteinizing Hormone; D013739:Testosterone; D014280:Triglycerides