Associations of endogenous testosterone and SHBG with glycated haemoglobin in middle-aged and older men

作者：Brand Judith S^*; Wareham Nicholas J; Dowsett Mitch; Folkerd Elizabeth; van der Schouw Yvonne T; Luben Robert N; Khaw Kay Tee

来源：Clinical Endocrinology, 2011, 74(5): 572-578.

DOI：10.1111/j.1365-2265.2010.03951.x

P>Objective
Low circulating levels of testosterone and sex-hormone-binding globulin (SHBG) are associated with increased cardiovascular risk in men. This association may be partially mediated through changes in glucose metabolism, but relatively few data are available on the relationship between sex hormones and markers of long-term glycaemia. We assessed the associations of endogenous testosterone and SHBG with glycated haemoglobin (HbA(1c)) in men.
Design and subjects
Cross-sectional study of 1292 men from the Norfolk population of European Prospective Investigation into Cancer (EPIC-Norfolk).
Measurements
Glycated haemoglobin, total testosterone (TT) and SHBG levels were measured, and free testosterone (FT) levels were calculated. Multiple linear regression models were used to assess the associations of TT, SHBG and FT with HbA(1c).
Results
Men with diabetes had lower testosterone and SHBG levels. In non-diabetic men, HbA(1c) levels were inversely associated with TT and calculated FT independently of age, body mass index, smoking, alcohol consumption and physical activity. The adjusted change in HbA(1c) was 0 center dot 055 (95% CI 0 center dot 025; 0 center dot 085) per standard deviation (SD) decrease in TT and 0 center dot 041 (95% CI 0 center dot 010; 0 center dot 073) per SD decrease in calculated FT, respectively. SHBG levels were inversely associated with HbA(1c) after multivariable adjustment (beta = 0 center dot 038 per SD decrease (95% CI 0 center dot 004; 0 center dot 071)).
Conclusions
In middle-aged and older men, low endogenous testosterone and SHBG levels are associated with glycaemia, even below the threshold for diabetes. Further studies are needed to determine the effects of interventions that raise testosterone levels in men having increased HbA(1c) and subnormal testosterone levels.

• 出版日期2011-5