Glomerular filtration rate and proteinuria associations with coronary artery calcium among HIV-infected and HIV-uninfected men in the Multicenter AIDS Cohort Study.

BACKGROUND: Decreased kidney function and greater albuminuria are associated with increased incidence and extent of coronary artery calcium (CAC). We investigated whether the associations between kidney function and urine protein-to-creatinine ratio (UPCR) with CAC differ by HIV serostatus. METHODS: Using data from the Multicenter AIDS Cohort Study, a prospective multicenter US study of men who have sex with men, we carried out a cross-sectional study comprised of 592 HIV-infected (HIV+) and 378 uninfected (HIV-) men who underwent noncontrast computed tomography to measure CAC. Logistic and linear regression models were used to determine whether HIV infection modified associations of estimated glomerular filtration rate and UPCR with the presence and extent of CAC, adjusting for age, race, and cardiovascular risk factors. RESULTS: Every 10 U decrease in estimated glomerular filtration rate below 90 ml/min/1.73 m was significantly associated with 1.3-fold [95% confidence interval (CI): 1.06-1.51] higher odds of CAC presence and was similar by HIV serostatus (Pinteraction=0.37). Greater UPCR was associated with more extensive CAC, with a change in log CAC score of 0.32 (95% CI: 0.10-0.55) per 1% increase in UPCR. There was a strong trend for effect modification by HIV serostatus for this association [HIV-: 0.75 (95% CI: 0.26-1.25); HIV+: 0.22 (95% CI: -0.03 to 0.47), Pinteraction=0.06]. CONCLUSION: Greater CAC burden is apparent among individuals with early kidney disease, irrespective of HIV serostatus. Increased UPCR is associated with a greater extent of CAC with a trend for differences by HIV serostatus; a clearer proteinuria/CAC extent relationship was apparent among HIV- patients.

Factors affecting glomerular filtration rate, as measured by iohexol disappearance, in men with or at risk for HIV infection.

OBJECTIVE: Formulae used to estimate glomerular filtration rate (GFR) underestimate higher GFRs and have not been well-studied in HIV-infected (HIV(+)) people; we evaluated the relationships of HIV infection and known or potential risk factors for kidney disease with directly measured GFR and the presence of chronic kidney disease (CKD). DESIGN: Cross-sectional measurement of iohexol-based GFR (iGFR) in HIV(+) men (n = 455) receiving antiretroviral therapy, and HIV-uninfected (HIV(-)) men (n = 258) in the Multicenter AIDS Cohort Study. METHODS: iGFR was calculated from disappearance of infused iohexol from plasma. Determinants of GFR and the presence of CKD were compared using iGFR and GFR estimated by the CKD-Epi equation (eGFR). RESULTS: Median iGFR was higher among HIV(+) than HIV(-) men (109 vs. 106 ml/min/1.73 m(2), respectively, p = .046), and was 7 ml/min higher than median eGFR. Mean iGFR was lower in men who were older, had chronic hepatitis C virus (HCV) infection, or had a history of AIDS. Low iGFR (≤90 ml/min/1.73 m(2)) was associated with these factors and with black race. Other than age, factors associated with low iGFR were not observed with low eGFR. CKD was more common in HIV(+) than HIV(-) men; predictors of CKD were similar using iGFR and eGFR. CONCLUSIONS: iGFR was higher than eGFR in this population of HIV-infected and -uninfected men who have sex with men. Presence of CKD was predicted equally well by iGFR and eGFR, but associations of chronic HCV infection and history of clinically-defined AIDS with mildly decreased GFR were seen only with iGFR.