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BackgroundOsteoporosis is common among HIV-infected persons and contributes to risk of fragility fracture. While ART initiation is associated with decreases in bone mineral density and increases in bone turnover, the impact of HIV on bone metabolism is unclear.MethodsWe identified men at the Chicago site of the Multicenter AIDS Cohort Study who HIV seroconverted while under observation. Concentrations of 25-OH vitamin D, bone turnover markers [procollagen type 1 N terminal propeptide (P1NP), osteocalcin (OC), C-telopeptide (CTX)] and sclerostin were measured from stored serum obtained at pre-HIV infection, pre-ART and post-ART initiation timepoints. Mixed models, with each biomarker as an outcome, were fitted. Timepoint, age, CD4 count (cells/mm 3 ), HIV-viral suppression, season and an age by timepoint interaction term were considered as fixed effects.ResultsData from 52 participants revealed that median duration between HIV seroconversion and ART initiation was 8.7 years (IQR 3.7-11.6). Median CD4 and plasma HIV-RNA concentrations were 445 (IQR 298.5-689) and 20 184 copies/mL (IQR 6237-64 340), respectively, at the pre-ART timepoint. Multivariate analyses demonstrated pre-HIV infection levels of OC that were higher than pre-ART levels (6.8 versus 5.7 ng/mL, P = 0.04); and pre-ART levels of sclerostin that were higher than post-ART levels (0.033 versus 0.02 ng/mL, P <0.001). No changes in P1NP, CTX and 25-OH vitamin D levels were detected.ConclusionsHIV seroconversion was associated with decreased OC levels while ART initiation was associated with decreases in sclerostin, a negative regulator of bone formation. Our results suggest that both HIV infection and ART have an impact on bone metabolism in white men.

BackgroundAging in males is associated with lower testosterone levels and a decrease in diurnal variation of testosterone secretion. Cross-sectional studies have shown lower than expected testosterone levels among HIV-infected men, but whether age-related changes in serum testosterone differ by HIV serostatus are not known.MethodsHIV-infected men from the Multicenter AIDS Cohort Study (MACS), age ≥ 45 years at highly active antiretroviral therapy initiation, who had ≥ 2 samples from the subsequent 10 years, were matched to HIV-uninfected men by age, race, MACS site, and calendar time of samples. Linear mixed-effects regression models were used to determine whether free testosterone (FT) and its rate of change differed by HIV serostatus.ResultsOne hundred eighty-two HIV-infected and 267 HIV-uninfected men were included, median age: 48.8 years (interquartile range: 45.8-53.4), median numbers of FT measurements per participant 4 (interquartile range: 3-5), 65% were drawn in the adjusted morning (AM). Mean-adjusted FT levels were lower among HIV-infected than HIV-uninfected men in AM samples {-6.1 ng/dL [95% confidence interval (CI): -9.8 to -2.4], P = 0.001}, but not in afternoon samples [-1.7 ng/dL (-6.0 to 2.6), P = 0.441]. The rate of FT decline with age did not differ by HIV serostatus: 9.2 ng/dL (95% CI: -13.4 to -5.0) per 10 years for HIV-infected vs. 7.9 ng/dL (95% CI: -10.2 to -5.5) for HIV-uninfected men, P = 0.578.ConclusionsFT decreased similarly with increasing age regardless of HIV serostatus. The lower AM, but not adjusted afternoon, FT levels among HIV-infected men compared with HIV-uninfected men suggest a loss of diurnal variation in FT levels among HIV-infected men.

BackgroundThere is limited evidence that among HIV-infected patients haemoglobin A1c (HbA1c) values may not accurately reflect glycaemia. We assessed HbA1c discordance (observed HbA1c - expected HbA1c) and associated factors among HIV-infected participants in the Multicenter AIDS Cohort Study (MACS).MethodsFasting glucose (FG) and HbA1c were measured at each semi-annual MACS visit since 1999. All HIV-infected and HIV-uninfected men for whom at least one FG and HbA1c pair measurement was available were evaluated. Univariate median regression determined the association between HbA1c and FG by HIV serostatus. The relationship between HbA1c and FG in HIV-uninfected men was used to determine the expected HbA1c. Generalized estimating equations determined factors associated with the Hb1Ac discordance among HIV-infected men. Clinically significant discordance was defined as observed HbA1c - expected HbA1c ≤-0.5%.ResultsOver 13 years, 1500 HIV-uninfected and 1357 HIV-infected men were included, with a median of 11 visits for each participant. At an FG of 125 mg/dL, the median HbA1c among HIV-infected men was 0.21% lower than among HIV-uninfected men and the magnitude of this effect increased with FG >126 mg/dL. Sixty-three percent of HIV-infected men had at least one visit with clinically significant HbA1c discordance, which was independently associated with: low CD4 cell count (<500 cells/mm(3)); a regimen containing a protease inhibitor, a non-nucleoside reverse transcriptase inhibitor or zidovudine; high mean corpuscular volume; and abnormal corpuscular haemoglobin.ConclusionHbA1c underestimates glycaemia in HIV-infected patients and its use in patients with risk factors for HbA1c discordance may lead to under-diagnosis and to under-treatment of established diabetes mellitus.