Serum total estradiol, but not testosterone is associated with reduced bone mineral density (BMD) in HIV-infected men: a cross-sectional, observational study

By investigating the relationship between serum testosterone, estradiol, and bone mineral density (BMD) in a large cohort of HIV-infected men, estradiol was associated with BMD, relative estrogen deficiency being involved in bone loss in men with hypogonadism, in addition to all HIV-related factors. Increased aromatization in adipose tissue does not counteract HIV-related bone loss. INTRODUCTION: The purpose of this study is to evaluate the relationship between serum testosterone, estradiol, and BMD in a large cohort of HIV-infected men. METHODS: We investigated biochemical, hormonal parameters, and BMD in 1204 HIV-infected men (age 45.64\u2009\ub1\u20097.33 years) participating in a cross-sectional, observational study. Among other parameters, the main outcome measures were serum total testosterone and estradiol, gonadotropins, 25-hydroxyvitamin D [25(OH)D], parathormone (PTH), calcium, phosphorous, femoral, and lumbar BMD. RESULTS: In men with HIV, the prevalence of osteoporosis and osteopenia is 15.1 and 63.2 % with 25(OH)D insufficiency being very common (60.1 %). After age adjustment, BMD is positively associated with estradiol, but not testosterone, at linear (p\u2009<\u20090.001) and stepwise (p\u2009<\u20090.05) multiple regression. Lumbar BMD significantly increases across the estradiol quartiles but not among testosterone quartiles. Femoral and lumbar BMD are significantly higher in men with estradiol\u2009 65\u200927 pg/mL than in those with estradiol <27 pg/mL. Apart from estradiol, only age, calcium, and BMI predict BMD at stepwise linear multiple regression, but the strength of this association is weak. CONCLUSIONS: Estradiol, but not testosterone, is associated with BMD in HIV-infected men and exerts a protective role on bone especially when it is above 27 pg/mL. Relative estrogen deficiency is a potential mechanism involved in bone loss in hypogonadal HIV-infected men, in addition to all HIV-related factors. Increased aromatization in adipose tissue does not counteract HIV-related bone loss. Finally, reduced BMD in young-to-middle-aged HIV-infected men might be considered a peculiar hallmark of HIV infection due to its relevant prevalence, representing one of the several pieces composing the complicated puzzle of premature aging related to HIV infection.Summary: By investigating the relationship between serum testosterone, estradiol, and bone mineral density (BMD) in a large cohort of HIV-infected men, estradiol was associated with BMD, relative estrogen deficiency being involved in bone loss in men with hypogonadism, in addition to all HIV-related factors. Increased aromatization in adipose tissue does not counteract HIV-related bone loss. Introduction: The purpose of this study is to evaluate the relationship between serum testosterone, estradiol, and BMD in a large cohort of HIV-infected men. Methods: We investigated biochemical, hormonal parameters, and BMD in 1204 HIV-infected men (age 45.64 \ub1 7.33\ua0years) participating in a cross-sectional, observational study. Among other parameters, the main outcome measures were serum total testosterone and estradiol, gonadotropins, 25-hydroxyvitamin D [25(OH)D], parathormone (PTH), calcium, phosphorous, femoral, and lumbar BMD. Results: In men with HIV, the prevalence of osteoporosis and osteopenia is 15.1 and 63.2\ua0% with 25(OH)D insufficiency being very common (60.1\ua0%). After age adjustment, BMD is positively associated with estradiol, but not testosterone, at linear (p < 0.001) and stepwise (p < 0.05) multiple regression. Lumbar BMD significantly increases across the estradiol quartiles but not among testosterone quartiles. Femoral and lumbar BMD are significantly higher in men with estradiol 65 27\ua0pg/mL than in those with estradiol