Urinary albumin excretion within the normal range is an independent risk for near-term development of kidney disease in HIV-infected patients

Abstract

Background. Epidemiological studies have raised awareness of the problem of undiagnosed kidney disease and suggest that early identification and treatment will reduce the global burden of patients requiring dialysis. However, there are insufficient data on how to identify subjects who are at risk for developing overt kidney disease in a human immunodeficiency virus (HIV) population. Methods. A 2-year prospective cohort study was conducted to determine the predictors of overt kidney disease. The cohort was comprised of a total of 507 HIV-infected participants with no evidence of kidney disease at baseline. Of which 429 participants completed the study. New-onset kidney disease was defined as the development of either microalbuminuria or renal dysfunction. Microalbuminuria was defined as urinary albumin-to-creatinine ratio (ACR) ≥30 mg/g. Renal dysfunction was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. Baseline ACR and eGFR were classified into three and two groups for analysis: 0-9, 10-19 and 20-29 mg/g and 60-89 and ≥90 mL/min/1.73 m2, respectively. Cox proportional hazards regression analysis was used to determine the baseline factors related to incident kidney disease. Results. The incidence of microalbuminuria, renal dysfunction and both illness were 8.4, 4.7 and 0.93% during the 2-year follow-up period, respectively. Baseline predictors of the development of microalbuminuria included the following (hazard ratio with 95% confidence interval): (i) age, 1.03 (1.00-1.07); (ii) diabetes mellitus (DM), 4.41 (1.04-16.1); (iii) hepatitis C virus (HCV) coinfection, 7.91 (1.56-33.2); (iv) ACR 10-19 mg/g, 11.5 (3.51-52.6) and (v) ACR 20-29 mg/g, 49.0 (13.9-236). Baseline predictors of the development of renal dysfunction included the following: (i) age, 1.03 (1.00-1.12); (ii) baseline eGFR 60-89 mL/min/1.73 m2, 7.86 (2.11-51.5); (iii) ACR 10-19 mg/g, 3.88 (1.28-12.6); (iv) ACR 20-29 mg/g, 6.64 (1.65-26.3) and (v) exposure to tenofovir-boosted protease inhibitors, 7.17 (2.57-23.4). The risks increased greatly with increasing number of concurrent predictors. Conclusions. Middle to high levels within the normal range of albuminuria is a significant risk factor for near-term development of overt kidney disease. In particular, HIV-infected patients with multiple risk factors including age, DM, HCV, low-grade albuminuria, a mild decrease in eGFR and use of tenofovir-boosted protease inhibitors should be closely monitored. © 2011 The Author.