Risk Factors for Kidney Toxicity in People with HIV

As reported at the recent 4th International AIDS Society Conference on HIV Treatment, Pathogenesis, and Prevention in Sydney, Australia (July 22-25, 2007), researchers conducted a study to estimate the prevalence of renal (kidney) failure in HIV-infected adult patients, and to identify the associated risk factors.

The cross-sectional study included patients in the Aquitaine Cohort in southwestern France. Between January 2004 and August 2006, 2588 patients were eligible. About 25% were women and the median age was 42 years. Patients with ascites, body mass index (BMI) <18 or >30, and pregnant women were excluded.

The median time since HIV diagnosis was 10 years and 22% of subjects had AIDS. The median CD4 count was 430 cells/mm3 and 60% had an HIV viral load below 50 copies/mL. Almost all (92%) had received antiretroviral therapy, including 25% who had taken tenofovir (Viread), a drug that has been linked to kidney dysfunction in some previous studies. In addition, 22% had hyperlipidemia, 7% had high blood pressure, and 3% had diabetes.

Renal function was estimated based on creatinine clearance, calculated using the Cockcroft-Gault formula. Renal failure was considered as creatinine clearance < 80 ml/min. Four stages of renal dysfunction were defined:

• mild if 60-80 ml/min;
• moderate if 30-60 ml/min;
• severe if 10-30 ml/min;
• end-stage if <10 ml/min.

Results

• The overall prevalence of renal failure was 22.6%:

- 17.7% mild;
- 4.4% moderate;
- 0.3% severe;
- 0.2% end-stage.

• In a multivariable analysis controlling for epidemiological, clinical, biological, and therapeutic variables, renal failure was associated with:

- age greater than 50 years (adjusted odds ratio [aOR] 13.3);
- BMI less than 22 kg/m2 (aOR 3.8);
- female sex (aOR 3.2);
- tenofovir exposure of more than 1 year (aOR 1.6);
- undetectable HIV viral load (aOR 1.6);
- AIDS diagnosis (aOR 1.3).

Conclusion

"Our study suggests a high prevalence of renal failure in HIV-infected patients," the investigators concluded. "Although advanced stages of renal impairment seem at date uncommon, renal function should be carefully monitored in those HIV patients with older age, low BMI, female gender, tenofovir exposure, undetectable viral load and AIDS stage."

Hopital Saint Andre, Internal Medicine Department, Bordeaux, France; INSERM U 593, Universite Bordeaux 2, Bordeaux, France; Hopital Pellegrin, Infectious Diseases Department, Bordeaux, France; Hopital Haut-Leveque, Internal Medicine Department, Bordeaux, France; COREVIH, University Hospital, Bordeaux, France; Hopital Robert Boulin, Internal Medecine Department, Libourne, France.

08/10/07

Reference
PJM Morlat, E Deti, S Lawson-Ayayi, and others. Prevalence and factors associated with renal failure in HIV infected patients, ANRS C03 Aquitaine Cohort, France. 4th International AIDS Society Conference on HIV Pathogenesis, Treatment, and Prevention. Sydney, Australia, July 22-25, 2007. Abstract MOPEB066.