Sex-Hormone Binding Globulin As Determinant of Radiological Vertebral Fractures in Male HIV Patients Under Antiretroviral Therapy

Presentation Number: SAT 308
Date of Presentation: April 1st, 2017

Stefano Frara*, Teresa Porcelli, Filippo Maffezzoni, Anna Maria Formenti, Maura Saullo, Andrea Giustina and Gherardo Mazziotti
University of Brescia, Italy

Abstract

Differently from what has been observed in the general population, HIV+ patients treated with HAART have increased risk of fragility fractures without significant differences between males and females. Moreover, HIV infection is frequently associated with hypogonadism the diagnosis of which is often challenging, due to variable values of gonadotropins and elevated circulating levels of sex-steroid biding globulin (SHBG). Whether hypogonadism may influence skeletal fragility in HIV patients is still largely unknown. In this cross-sectional study, we aimed at evaluating the association between bone mineral density (BMD, Hologic DEXA), radiological vertebral fractures (VFs) and serum gonadotropins (LH and FSH), total testosterone (TT), SHBG and calculated free (fT) testosterone in 103 subjects affected by HIV. VFs were found in 34 patients (33%); 15 had multiple fractures and 7 had at least one moderate-to-severe VF. Only 26% showed osteoporosis, whilst 13% had normal BMD and 61% had osteopenia. 26% had an increase in FSH and/or LH, but only 4 patients showed contextually a reduction in TT. We observed increased SHBG values with reduced fT in 29% of subjects. In univariate analysis, VFs were significantly associated with high levels of FSH (OR 4.2; p=0.02), high SHBG (OR 3.6; p=0,02), patients’ age (OR 1.1; p=0,01) and pathological T-scores (OR 4.0; p=0,001), whereas no association was observed between VFs and TT (p=0.47), fT (p=0.5) or LH (p=0.59). Elevated SHBG, but not FSH, also correlated with pathological T-score values (OR 2.7; p=0,03).
In conclusion, our study suggested an influence of gonadal status on VFs risk in males affected by HIV, consistently with the concept that increased levels of SHBG and FSH might be markers of hypogonadism. However, we cannot exclude that high circulating SHBG may have a direct and independent effect on skeletal health in HIV patients, such as already demonstrated in male patients with primary osteoporosis.

 

Disclosure: AG: Ad Hoc Consultant, Abiogen. GM: Chairman, Abiogen. Nothing to Disclose: SF, TP, FM, AMF, MS