Sex hormone‐binding globulin is associated with androgen deficiency features independently of total testosterone. (8th January 2018)

• Record Type: Journal Article
• Authors: Rastrelli, Giulia; Corona, Giovanni; Cipriani, Sarah; Mannucci, Edoardo; Maggi, Mario
• Is Part Of: Clinical endocrinology. Volume 88:Number 4(2018)
• Page Start: 556
• Page End: 564
• Publication Date: 2018-01-08
• Subjects: haematocrit -- hormone bioactivity -- hypogonadism -- male -- prostate‐specific antigen -- sex hormone‐binding globulin -- testosterone; Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.13530
• Languages: English
• ISSNs: 0300-0664

Abstract

Summary: Objective: It is recognized that total testosterone (TT) does not sufficiently describe androgen status when sex hormone‐binding globulin (SHBG) is altered. However, in humans, evidence supporting the existence of a hypogonadism due to low T bioactivity is scanty. The aim of the study was to assess whether changes in SHBG levels, independently of TT, are associated with subjective and objective androgen‐dependent parameters. Design: Cross‐sectional observation. Patients: Two thousand six hundred and twenty‐two men (aged 51.1 ± 13.5 years) attending a Sexual Medicine and Andrology Outpatient Clinic for sexual dysfunctions. Measurements: All patients underwent a standardized diagnostic protocol before starting any treatment. Clinical and biochemical parameters have been collected. Higher ANDROTEST score has been used as a comprehensive marker of more severe hypogonadal symptoms. Prostate‐specific antigen (PSA) and haematocrit have been used as objective surrogate markers of T bioactivity. Results: After adjusting for TT and lifestyle, SHBG showed a significant positive association with ANDROTEST score ( B = 0.79 [0.61; 0.96], P < .0001). Conversely, higher SHBG, independently of TT, was negatively related to PSA ( B = −0.86 [−0.83; −0.89]; P < .0001) and haematocrit ( B = −0.64 [−0.88; −0.40]; P < .0001), after adjustment for the aforementioned confounders along with age and body mass index. Furthermore, a relationship between SHBG and lipids or blood pressure was found, with lower SHBG levels associated with a worse metabolic profile, independently of TT. Conclusions: Higher SHBG, independently of TT, is associated with either subjective or objective androgen deficiency features. This indicates that besides a hypogonadism due to an impaired T production, a hypogonadism due to a lower biological activity of T does exist.