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Testosterone Falls No More With Than Without HIV Over 6 Years in MACS
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CROI 2014, March 3-6, 2014, Boston
Mark Mascolini
Free testosterone did not fall more through 6 years of follow-up in HIV-positive than HIV-negative older men in the Multicenter AIDS Cohort Study (MACS) [1]. HIV-positive men had lower morning but not afternoon/evening testosterone levels than matched HIV-negative men, a finding that may indicate loss of diurnal variation in older men with HIV.
Testosterone declines with age may play a role in age-related conditions such as cardiovascular disease, glucose abnormalities, osteoporosis, sarcopenia (muscle mass loss), and sexual dysfunction, noted Laurence Slama (Tenon Hospital, Paris) and MACS colleagues. Testosterone levels and diurnal variation also drop with age in the general male population. Cross-sectional studies show lower than expected testosterone levels in men with HIV. But no longitudinal study addressed testosterone changes in men with versus without HIV until this MACS analysis.
MACS is an ongoing study of US men who have sex with men with or without HIV infection. Cohort members make twice-yearly study visits for check-ups, interviews, and blood draws. The testosterone analysis included men 45 and older when they began antiretroviral therapy (ART). All men had a serum sample from before they started ART and two or more samples after starting. Slama and colleagues matched each HIV-positive man to an HIV-negative man by age, race, MACS site, and calendar time for the pre-ART and on-ART samples. The researchers excluded men who took hormones of any kind or had testosterone levels high enough (above 150 ng/dL) to suggest unreported testosterone use.
The analysis included 182 HIV-positive and 267 HIV-negative men, 82% and 85% white. The positive men had a slightly but significantly lower average body mass index (25.1 versus 26.3 kg/m2, P = 0.002). A significantly higher proportion of positive men also had HCV infection (10% versus 4%, P = 0.008), and a nonsignificantly higher proportion had diabetes (8% versus 5%, P = 0.14).
Study participants had a median of 4 testosterone measurements over a median 6 years. Average morning testosterone levels were significantly lower in men with HIV (67 versus 72 ng/dL, P = 0.037), and afternoon/evening levels were the same in both groups (65 ng/dL in both groups, P = 0.728).
Free testosterone dropped significantly over time (P < 0.001) both in men with HIV and without HIV. But after statistical adjustment for time of the sample draw and other covariates, the drop was no greater in men with than without HIV (with HIV -1.1% per year, 95% confidence interval [CI] -0.4% to -1.8%; without HIV -1.0% per year, 95% CI -0.6% to -1.5%, P = 0.913).
Because free testosterone peaks in the morning and hits its nadir in the afternoon or evening, the researchers believe their findings "may suggest that, similar to aging, HIV-infection is associated with a loss of diurnal variation in free testosterone." They call for further research to measure free testosterone in the morning and afternoon/evening in each study participant.
Reference
1. Slama L, Jacobson LP, Li X, et al. Longitudinal changes in free testosterone among older HIV-infected and HIV-uninfected men. CROI 2014. Conference on Retroviruses and Opportunistic Infections. March 3-6, 2014. Boston. Abstract 754.
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