title: Higher Cystatin C Levels Are Associated With Neurocognitive Impairment in Older HIV+ Adults.
abstract: OBJECTIVE
  The study aims to determine whether cystatin C is associated with HIV disease and HIV-associated neurocognitive impairment (NCI).
  
  
  METHODS
  Participants included 124 (HIV+ n = 77; HIV- n = 47) older adults (age ≥ 50 years) examined at the University of California, San Diego HIV Neurobehavioral Research Program. Cystatin C, a biomarker of kidney functioning that has been linked to poor health outcomes, was measured in blood. Participants completed a comprehensive neurocognitive assessment that was used to define both global and domain NCI.
  
  
  RESULTS
  The HIV+ group had significantly higher cystatin C concentrations than the HIV- group (d = 0.79 P < 0.001). Among HIV+ participants, those with NCI had higher cystatin C concentrations than those without NCI (d = 0.42, P = 0.055), particularly among participants taking tenofovir (d = 0.78, P = 0.004). A receiver-operator characteristic curve identified that cystatin C levels ≥0.75 mg/L were associated with NCI in the HIV+ group. Using this binary variable and including relevant covariates, multivariate modeling confirmed that NCI was associated with higher cystatin C levels (OR = 3.0; P = 0.03).
  
  
  CONCLUSIONS
  Our results confirm that HIV+ older adults have higher cystatin C than HIV- older adults and further identify that cystatin C may be associated with NCI in this population, particularly if they use tenofovir. This blood biomarker may be a useful clinical tool to identify older HIV+ persons at greater risk for cognitive decline.
authors.affiliation: *Department of School of Medicine, John A. Burns School of Medicine, University of Hawaii Honolulu, HI; Departments of †Psychiatry; ‡Neurosciences, University of California, San Diego, San Diego, CA; §Stein Institute for Research on Aging, University of California, San Diego, San Diego, CA; and ‖Department of Medicine, University of California, San Diego, San Diego, CA.
authors.forename: Marissa E
authors.initials: ME
authors.lastname: Sakoda
authors.forename: Pariya L
authors.initials: PL
authors.lastname: Fazeli
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Ellis
authors.forename: Dilip V
authors.initials: DV
authors.lastname: Jeste
authors.forename: Igor
authors.initials: I
authors.lastname: Grant
authors.forename: Scott L
authors.initials: SL
authors.lastname: Letendre
authors.forename: David J
authors.initials: DJ
authors.lastname: Moore
mesh_terms: D015526:AIDS Dementia Complex / Q000473:pathology*; D000367:Age Factors; D000368:Aged; D002140:California; D015331:Cohort Studies; D055316:Cystatin C / Q000097:blood*; D005260:Female; D015658:HIV Infections / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D055316:Cystatin C