title: Cystatin C level as a marker of kidney function in human immunodeficiency virus infection: the FRAM study.
abstract: BACKGROUND
  Although studies have reported a high prevalence of end-stage renal disease in human immunodeficiency virus (HIV)-infected individuals, little is known about moderate impairments in kidney function. Cystatin C measurement may be more sensitive than creatinine for detecting impaired kidney function in persons with HIV.
  
  
  METHODS
  We evaluated kidney function in the Fat Redistribution and Metabolic Change in HIV Infection (FRAM) cohort, a representative sample of 1008 HIV-infected persons and 290 controls from the Coronary Artery Risk Development in Young Adults (CARDIA) study in the United States.
  
  
  RESULTS
  Cystatin C level was elevated in HIV-infected individuals; the mean +/- SD cystatin C level was 0.92 +/- 0.22 mg/L in those infected with HIV and 0.76 +/- 0.15 mg/L in controls (P < .001). In contrast, both mean creatinine levels and estimated glomerular filtration rates appeared similar in HIV-infected individuals and controls (0.87 +/- 0.21 vs 0.85 +/- 0.19 mg/dL [to convert to micromoles per liter, multiply by 88.4] [P = .35] and 110 +/- 26 vs 106 +/- 23 mL/min/1.73 m(2) [P = .06], respectively). Persons with HIV infection were more likely to have a cystatin C level greater than 1.0 mg/L (OR, 9.8; 95% confidence interval, 4.4-22.0 [P <.001]), a threshold demonstrated to be associated with increased risk for death and cardiovascular and kidney disease. Among participants with HIV, potentially modifiable risk factors for kidney disease, hypertension, and low high-density lipoprotein concentration were associated with a higher cystatin C level, as were lower CD4 lymphocyte count and coinfection with hepatitis C virus (all P < .001).
  
  
  CONCLUSIONS
  Individuals infected with HIV had substantially worse kidney function when measured by cystatin C level compared with HIV-negative controls, whereas mean creatinine levels and estimated glomerular filtration rates were similar. Cystatin C measurement could be a useful clinical tool to identify HIV-infected persons at increased risk for kidney and cardiovascular disease.
authors.affiliation: Department of Medicine, San FranciscoVeterans Affairs Medical Center 4150 Clement Street, San Francisco, CA 94121, USA.
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Odden
authors.forename: Rebecca
authors.initials: R
authors.lastname: Scherzer
authors.forename: Peter
authors.initials: P
authors.lastname: Bacchetti
authors.forename: Lynda Anne
authors.initials: LA
authors.lastname: Szczech
authors.forename: Stephen
authors.initials: S
authors.lastname: Sidney
authors.forename: Carl
authors.initials: C
authors.lastname: Grunfeld
authors.forename: Michael G
authors.initials: MG
authors.lastname: Shlipak
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000150:complications*; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D005919:Glomerular Filtration Rate; D015658:HIV Infections / Q000097:blood* / Q000150:complications; D006801:Humans; D007668:Kidney / Q000503:physiopathology*; D007674:Kidney Diseases / Q000097:blood* / Q000150:complications; D008297:Male; D012680:Sensitivity and Specificity
chemical_list: C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D003404:Creatinine