title: Albuminuria and the risk of incident stroke and stroke types in older adults.
abstract: BACKGROUND
  The kidney biomarker that best reflects risk of stroke is unknown. We sought to evaluate the association of stroke with 3 kidney biomarkers: albuminuria, cystatin C, and glomerular filtration rate.
  
  
  METHODS
  These 3 biomarkers were determined in 3,287 participants without history of stroke from the Cardiovascular Health Study, a longitudinal cohort study of men and women age 65 years and older from 4 US communities. The biomarkers were albuminuria ascertained using urinary albumin-to-creatinine ratio (UACR) from morning spot urine, creatinine-based estimated glomerular filtration rate (eGFR), and cystatin C. Outcomes were incident stroke (any, ischemic, or hemorrhagic) during follow-up between 1996 and 2006.
  
  
  RESULTS
  A total of 390 participants had an incident stroke: 81% ischemic, 12% hemorrhagic, and 7% unclassified. In adjusted Cox regression models, UACR was more strongly related to any stroke, ischemic stroke, and hemorrhagic stroke than eGFR and cystatin C. The hazard ratio (HR) of any stroke comparing the top to bottom quintile of UACR was 2.10 (95% confidence interval [CI] 1.47-3.00), while HR for eGFR was 1.29 (95% CI 0.91-1.84) and for cystatin C was 1.22 (95% CI 0.85-1.74). When considering clinically relevant categories, elevated UACR was associated with increased hazard of any stroke and ischemic stroke regardless of eGFR or cystatin C categories.
  
  
  CONCLUSIONS
  UACR was the kidney biomarker most strongly associated with risk of incident stroke. Results in this elderly cohort may not be applicable to younger populations. These findings suggest that measures of glomerular filtration and permeability have differential effects on stroke risk.
authors.affiliation: Division of Neurology, Mayo Clinic Arizona, Phoenix, AZ 85054, USA. Aguilar.Maria@Mayo.edu
authors.forename: M I
authors.initials: MI
authors.lastname: Aguilar
authors.forename: E S
authors.initials: ES
authors.lastname: O'Meara
authors.forename: S
authors.initials: S
authors.lastname: Seliger
authors.forename: W T
authors.initials: WT
authors.lastname: Longstreth
authors.forename: R G
authors.initials: RG
authors.lastname: Hart
authors.forename: P E
authors.initials: PE
authors.lastname: Pergola
authors.forename: M G
authors.initials: MG
authors.lastname: Shlipak
authors.forename: R
authors.initials: R
authors.lastname: Katz
authors.forename: M J
authors.initials: MJ
authors.lastname: Sarnak
authors.forename: D E
authors.initials: DE
authors.lastname: Rifkin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000419:Albuminuria / Q000175:diagnosis / Q000209:etiology*; D003153:Community Health Services; D016001:Confidence Intervals; D005260:Female; D015577:Geriatric Assessment; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D020521:Stroke / Q000145:classification* / Q000150:complications* / Q000453:epidemiology / Q000652:urine*
references.citation: Mayo Clin Proc. 2008 Jul;83(7):806-12
references.pmid: 18613997
references.citation: J Am Coll Cardiol. 2005 Jan 18;45(2):268-71
references.pmid: 15653026
references.citation: Am J Epidemiol. 2008 May 15;167(10):1226-34
references.pmid: 18385206
references.citation: Diabetes Care. 1997 Jul;20(7):1183-97
references.pmid: 9203460
references.citation: Stroke. 2007 Dec;38(12):3121-6
references.pmid: 17962588
references.citation: Stroke. 2007 Dec;38(12):3127-32
references.pmid: 17962600
references.citation: J Neurol Sci. 2008 Aug 15;271(1-2):53-60
references.pmid: 18442832
references.citation: J Neurol Sci. 2007 Apr 15;255(1-2):27-34
references.pmid: 17320908
references.citation: Ann Intern Med. 2003 Jul 15;139(2):137-47
references.pmid: 12859163
references.citation: N Engl J Med. 2005 May 19;352(20):2049-60
references.pmid: 15901858
references.citation: Hypertension. 2000 Apr;35(4):898-903
references.pmid: 10775558
references.citation: Neurology. 2001 Feb 13;56(3):368-75
references.pmid: 11171903
references.citation: JAMA. 2007 Nov 7;298(17):2038-47
references.pmid: 17986697
references.citation: JAMA. 2001 Jul 25;286(4):421-6
references.pmid: 11466120
references.citation: Ann Epidemiol. 1991 Feb;1(3):263-76
references.pmid: 1669507
references.citation: Hypertension. 2003 Nov;42(5):1050-65
references.pmid: 14604997
references.citation: Stroke. 1991 Sep;22(9):1155-63
references.pmid: 1926258
references.citation: J Am Soc Nephrol. 2005 Dec;16(12):3721-7
references.pmid: 16236809
references.citation: Am J Kidney Dis. 2009 Mar;53(3):438-47
references.pmid: 19070412
references.citation: Arch Intern Med. 1997 Jul 14;157(13):1413-8
references.pmid: 9224218
references.citation: Stroke. 1999 Sep;30(9):1787-91
references.pmid: 10471424
references.citation: Ann Intern Med. 2003 Dec 2;139(11):901-6
references.pmid: 14644892
references.citation: Am J Kidney Dis. 2008 Mar;51(3):395-406
references.pmid: 18295055
references.citation: Stroke. 2007 Dec;38(12):3287-8
references.pmid: 17947596
references.citation: Am J Kidney Dis. 2003 Sep;42(3):466-73
references.pmid: 12955674
references.citation: Ann Intern Med. 2006 Aug 15;145(4):237-46
references.pmid: 16908914
references.citation: Am J Kidney Dis. 2004 Jul;44(1):25-34
references.pmid: 15211434
references.citation: Cerebrovasc Dis. 2002;14(1):15-21
references.pmid: 12097846
references.citation: Kidney Int. 2003 Mar;63(3):1121-9
references.pmid: 12631096
references.citation: Circulation. 2005 Aug 16;112(7):969-75
references.pmid: 16087792
references.citation: Atherosclerosis. 2006 Aug;187(2):372-7
references.pmid: 16242696
references.citation: Methods Inf Med. 1990 Sep;29(4):362-74
references.pmid: 2233384
references.citation: J Clin Hypertens (Greenwich). 2004 Nov;6(11 Suppl 3):8-12
references.pmid: 15538105