Glomerular filtration rate estimated using creatinine, cystatin C or both markers and the risk of clinical events in HIV-infected individuals.

Objectives The accuracy and precision of glomerular filtration rate ( GFR) estimating equations based on plasma creatinine ( GFR_cr), cystatin C ( GFR_cys) and the combination of these markers ( GFR_cr-cys) have recently been assessed in HIV-infected individuals. We assessed the associations of GFR, estimated by these three equations, with clinical events in HIV-infected individuals. Methods We compared the associations of baseline GFR_cr, GFR_cys and GFR_cr-cys [using the Chronic Kidney Disease Epidemiology Collaboration ( CKD-EPI) equations] with mortality, cardiovascular events ( CVEs) and opportunistic diseases ( ODs) in the Strategies for the Management of Antiretroviral Therapy ( SMART) study. We used Cox proportional hazards models to estimate unadjusted and adjusted hazard ratios per standard deviation ( SD) change in GFR. Results A total of 4614 subjects from the SMART trial with available baseline creatinine and cystatin C data were included in this analysis. Of these, 99 died, 111 had a CVE and 121 had an OD. GFR_cys was weakly to moderately correlated with HIV RNA, CD4 cell count, high-sensitivity C-reactive protein, interleukin-6, and D-dimer, while GFR_cr had little or no correlation with these factors. GFR_cys had the strongest associations with the three clinical outcomes, followed closely by GFR_cr-cys, with GFR_cr having the weakest associations with clinical outcomes. In a model adjusting for demographics, cardiovascular risk factors, HIV-related factors and inflammation markers, a 1- SD lower GFR_cys was associated with a 55% [95% confidence interval ( CI) 27−90%] increased risk of mortality, a 21% (95% CI 0−47%) increased risk of CVE, and a 22% (95% CI 0−48%) increased risk of OD. Conclusions Of the three CKD-EPI GFR equations, GFR_cys had the strongest associations with mortality, CVE and OD. [ABSTRACT FROM AUTHOR]