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Testosterone Lower in AM But Not PM in MACS Men With vs Without HIV
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IWCADR: Longitudinal Changes in Free Testosterone among Older HIV-infected and HIV-uninfected Men - (09/09/14)
16th International Workshop on Co-Morbidities and Adverse Drug Reactions in HIV
Oct 6-8, 2014
5th International Workshop on HIV and Aging. October 21-22, 2014. Baltimore
Mark Mascolini
Morning testosterone levels were significantly lower in HIV-positive than negative men in the Multicenter AIDS Cohort Study (MACS) [1]. But afternoon/evening levels did not differ between men with and without HIV. And testosterone concentrations did not drop more annually in HIV-positive men than HIV-negative men in this 6-year study.
Testosterone levels fall as men in the general population age, and diurnal variation in testosterone secretion decreases with age. Prior cross-sectional studies found lower than expected testosterone concentrations in men with HIV, but no longitudinal study had determined whether age-related changes in testosterone differ by HIV status.
To find out, researchers from Tenon Hospital in Paris and MACS investigators at Johns Hopkins University compared gay/bisexual men with and without HIV in the MACS cohort. All men were 45 or older when they started antiretroviral therapy (ART), all had one or more serum samples from before starting ART, and all had two or more samples in the 10 years after starting therapy. The researchers matched HIV-positive men to HIV-negative men by age, race, MACS site, and calendar time of pre-ART and on-ART samples. They excluded anyone taking exogenous hormones and anyone with free testosterone concentrations above 150 ng/dL, which suggest unreported testosterone use.
The study involved 182 men with HIV and 267 HIV-negative men. Age at the time of pre-ART sampling averaged 51 in the HIV group and 49 in the HIV-negative group (P < 0.001). Over 80% in each group were Caucasian. Mean body mass index was slightly but significantly lower in men with HIV (25.1 versus 26.3 kg/m2, P = 0.002). Participants gave a median of 4 samples (interquartile range [IQR] 3 to 5) over a median of 6 years (IQR 2.9 to 9.5). Two thirds of the 1737 samples analyzed (65%) were drawn in the morning.
After statistical adjustment for age, race, body mass index, hepatitis C status, smoking, diabetes mellitus, and MACS site, average free testosterone in morning samples was significantly lower in men with HIV (67 ng/dL, 95% confidence interval [CI] 65 to 71) than in men without HIV (72 ng/dL, 95% CI 69 to 74) (P = 0.037). But in afternoon/evening samples, average free testosterone concentrations did not differ in men with and without HIV (both 65 ng/dL).
Through 10 years free testosterone dropped significantly in men with and without HIV (P < 0.001). After statistical adjustment for time of sampling and other variables, annual rate of free testosterone decline did not differ significantly between men with HIV (-1.1%, 95% CI -0.4% to -1.8%) and men without HIV (-1.0%, 95% CI -0.6% to -1.5%) (P = 0.913).
The researchers concluded that morning free testosterone is lower in men with than without HIV, but afternoon levels do not differ by HIV status. Because free testosterone peaks in the morning and hits its nadir in the afternoon, they believe these findings "may suggest that, similar to aging, HIV infection is associated with a loss of diurnal variation in free testosterone."
But they proposed that interpretation with caution because each study participant did not provide both AM and PM samples. They also noted that excluding men who reported testosterone use may have eliminated men with "more pronounced gonadal dysfunction." Finally, they stressed that age distribution in their study population was narrow.
Reference
1. Slama L, Jacobson L, Li X, et al. Longitudinal changes in free testosterone among older HIV-infected and HIV-uninfected men. 5th International Workshop on HIV and Aging. October 21-22, 2014. Baltimore. Abstract 8.
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