title: Cystatin C and frailty in older men.
abstract: OBJECTIVE
  To determine whether higher cystatin C would be associated with greater frailty in men aged 65 and older.
  
  
  METHODS
  Cross-sectional cohort study.
  
  
  METHODS
  Six U.S. sites.
  
  
  METHODS
  A random sample of community-dwelling men aged 65 and older enrolled in the Osteoporotic Fractures in Men (MrOS) Study (mean age 73.8; 9.8% frail and 47.2% intermediate frailty; N = 1,602).
  
  
  METHODS
  Serum cystatin C, creatinine, and frailty were measured. Frailty was analyzed as an ordinal outcome of robust, intermediate frailty, and frail using a multinomial logistic regression model, and the base model was adjusted for age, race, and clinical site.
  
  
  RESULTS
  Higher cystatin C was associated with seven times greater odds of being frail than being robust (odds ratio (OR) quartile 4 vs 1 = 7.12, 95% confidence interval (CI) = 3.76-13.46) and 2.4 times greater odds of intermediate frailty than robust (OR quartile 4 vs 1 = 2.38, 95% CI = 1.70-3.32). The association was attenuated but persisted after adjusting for multiple possible confounders. In contrast, neither higher serum creatinine (OR quartile 4 vs 1 = 1.36, 95% CI = 0.78-2.40) nor lower creatinine-based estimated glomerular filtration rate (OR quartile 4 vs 1 = 1.01, 95% CI = 0.54-1.87) was associated in a graded manner with greater odds of frailty.
  
  
  CONCLUSIONS
  Higher cystatin C, but not creatinine-based measures, was associated with greater odds of frailty in this cohort of older men.
authors.affiliation: Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Allyson
authors.initials: A
authors.lastname: Hart
authors.forename: Misti L
authors.initials: ML
authors.lastname: Paudel
authors.forename: Brent C
authors.initials: BC
authors.lastname: Taylor
authors.forename: Areef
authors.initials: A
authors.lastname: Ishani
authors.forename: Eric S
authors.initials: ES
authors.lastname: Orwoll
authors.forename: Peggy M
authors.initials: PM
authors.lastname: Cawthon
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D055316:Cystatin C / Q000097:blood*; D005500:Follow-Up Studies; D016330:Frail Elderly; D005919:Glomerular Filtration Rate; D006801:Humans; D015994:Incidence; D008297:Male; D009391:Nephelometry and Turbidimetry; D058866:Osteoporotic Fractures / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D011379:Prognosis; D011446:Prospective Studies; D051437:Renal Insufficiency / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D014481:United States / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D055316:Cystatin C; D003404:Creatinine
keywords: creatinine; cystatin C; elderly; frailty; kidney function