The importance of SHBG and calculated free testosterone for the diagnosis of symptomatic hypogonadism in HIV-infected men: a single-centre real-life experience

Abstract

Purpose The prevalence of low testosterone and symptoms of hypogonadism in HIV-infected men is still debated. We aimed to estimate the prevalence and type of hypogonadism in HIV-infected males complaining about sexual symptoms, and to evaluate the role of calculated free testosterone (cFT) vs total testosterone (TT) for diagnosis. Furthermore, we evaluated relationship between sex hormone-binding globulin (SHBG), gonadal status and clinical and virologic parameters. Methods We retrospectively evaluated 169 HIV-infected men with sexual symptoms, with TT available. Among them, we selected 94 patients with TT, SHBG, cFT, and luteinizing hormone (LH) available, and classified hypogonadism into overt (low TT and/or low cFT) and compensated (high LH, normal TT and cFT). Comparison was performed by non-parametric Kruskal–Wallis test and Spearman’s correlation was calculated to verify the possible associations. Results Overt and compensated hypogonadism were found in 20.2% and 13.8% of patients, respectively. With reliance on TT alone, only 10.6% of patients would have met diagnosis. SHBG values were elevated in one third of patients, and higher in men with compensated hypogonadism. Significant positive correlation was found between SHBG and HIV infection duration, TT and LH. Conclusion Only a complete hormonal profile can properly diagnose and classify hypogonadism in HIV-infected men complaining about sexual symptoms. TT alone reliance may lead to half of diagnoses missing, while lack of gonadotropin prevents the identification of compensated hypogonadism. This largely comes from high SHBG, which seems to play a central role in the pathogenesis of hypogonadism in this population.

Impact of hypogonadism on bone mineral density and vertebral fractures in HIV-infected men

“…Moreover, Jing et al [ 40 ] showed that FSH increase was associated with higher risk of osteoporosis/osteopenia in type 2 diabetic men. We previously showed that elevated SHBG levels are very common in HIV-infected men [ 18 , 41 ] and might represent the primum movens of the compensated form of hypogonadism in these patients. In fact, an increase in SHBG would lower the amount of free testosterone and oestradiol, with subsequent compensatory increase in LH production from the pituitary gland, which is able to maintain the testicular production of testosterone.…”

“…Elevated LH with normal TT and cFT levels identified compensated hypogonadism. More details on hypogonadism assessment in this population are shown elsewhere [ 18 ].…”

Correlation between different equations to calculate free testosterone for improved detection of hypogonadism in people living with HIV

“…screened, in line with the 18.8% prevalence recorded in this study. 25 This study is limited by the absence of relevant clinical information required to confirm the diagnosis and the absence of serum gonadotropins to distinguish between primary and secondary hypogonadism. However the scope of this work was to assess the agreement between different methods to estimate serum testosterone levels and how this could impact on overall prevalence of biochemical hypogonadism.…”

Sex-Specific Associations of Testosterone and Genetic Factors With Health Span

“…Besides, individuals with a very high or very low level of testosterone are strongly associated with health status ( 46 , 47 ). Some diseases, such as pituitary disorders ( 48 ), HIV ( 49 ), and hyperthyroidism ( 50 ), as well as obesity ( 51 ), may interfere the testosterone production, increasing the possibility of extreme level of occurrence. It is worth noting that these diseases have a possible influence on personal health span as well.…”