Background: Guidelines for kidney function monitoring and antiretroviral drug dosing are available and respectively refer to glomerular filtration rate and creatinine clearance (CrCl).
Objective: The aim of the study was to compare kidney function estimates vs. measured 24-h CrCl in HIV-infected subjects.
Methods: A cross-sectional design was used, with comparison of Cockcroft-Gault (CG), original and simplified modification of diet in renal disease (MDRD) equations vs. measured 24-h CrCl. Subjects were HIV-infected, 18-70 years old, without pre-existing kidney disease.
Results: Results are presented as mean (+/-standard deviation), unless otherwise stated. The study population consisted of 90 patients, of whom 71% were male, with a mean age of 45 years (+/-6.5 years). At the time of evaluation, the mean body mass index was 23 (+/-3.3); mean serum creatinine was 0.91 mg/dL (+/-0.2 mg/dL); and mean blood urea nitrogen (BUN) was 34.7 mg/dL (+/-10.6 mg/dL). Differences between paired methods were all significant (P<0.00001), except between CG and simplified MDRD (P=0.21; Pearson r=0.81). In univariate analysis, male gender, CD4 nadir, hepatitis B virus coinfection, BUN and current CD4 cell count showed a significant positive correlation (P<0.2) with the difference between measured 24-h CrCl and either CG or simplified MDRD estimates. In multivariate analysis, only BUN showed a significant positive correlation (P<0.05).
Conclusions: Estimates were lower than the measurements of 24-h CrCl. Original MDRD estimates were lower than those with other equations. CG and simplified MDRD estimates showed a satisfactory correlation.