Kidney dysfunction and fatal cardiovascular disease--an association independent of atherosclerotic events: results from the Health, Aging, and Body Composition (Health ABC) study.
BACKGROUND
Impaired kidney function has been associated with increased risk for death, myocardial infarction, stroke, and heart failure in high-risk populations. We evaluated whether impaired kidney function predicted risk of fatal cardiovascular disease independent of prevalent and incident cardiovascular events.


METHODS
The Health, Aging, and Body Composition study is a cohort of well-functioning, elderly participants aged 70 to 79 years at entry. We measured serum cystatin C and creatinine from baseline plasma samples of 3044 participants and followed them over 6 years, examining the associations among kidney function, cardiovascular death, and incident cardiovascular events. Cystatin C was categorized as low (< 0.84 mg/L), medium (0.84-1.18 mg/L), or high (> or = 1.19 mg/L); serum creatinine (cutoff value of > or = 1.3 in women and > or = 1.5 in men) and estimated glomerular filtration rate (eGFR; greater and less than 60 mL/min per 1.73 m2) were dichotomized.


RESULTS
During follow-up, 242 cardiovascular deaths occurred, of which 69 were in participants without prior cardiovascular events; 294 incident cardiovascular events occurred including 135 myocardial infarctions and 163 strokes. Higher cystatin C concentrations were significantly associated with cardiovascular death (adjusted hazard ratio [HR] 1.70, 95% confidence interval [CI] 1.05-2.76 for the medium cystatin C group; and HR 2.24, 95% CI 1.30-3.86 for the high cystatin C group, relative to the low cystatin C group). The point estimate was of greater magnitude in the analysis that excluded prevalent cardiovascular disease (adjusted HR 2.68, 95% CI 0.94-7.70 for the medium cystatin C group; and HR 4.91, 95% CI, 1.55-15.54 for the high cystatin C group). Elevated creatinine levels (adjusted HR 1.54, 95% CI 1.02-2.33, and HR 2.28, 95% CI 1.10-4.73 among participants without a history of cardiovascular disease) were also associated with cardiovascular death. No significant association was found between low eGFR and cardiovascular death. In addition, cystatin C, low eGFR, or elevated creatinine levels were not associated with other cardiovascular events.


CONCLUSIONS
Impaired kidney function is a strong predictor of cardiovascular death, particularly among participants without prior history of cardiovascular disease.
Deo
Rajat
R
Division of Cardiology, Johns Hopkins Hospital, Baltimore, MD, USA.
Fyr
Christina L Wassel
CL
Fried
Linda F
LF
Newman
Anne B
AB
Harris
Tamara B
TB
Angleman
Sara
S
Green
Christie
C
Kritchevsky
Stephen B
SB
Chertow
Glenn M
GM
Cummings
Steven R
SR
Shlipak
Michael G
MG
D017677:Age Distribution; D000368:Aged; D000375:Aging / Q000502:physiology; D050197:Atherosclerosis / Q000175:diagnosis / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D001823:Body Composition; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology*; D002423:Cause of Death; D015331:Cohort Studies; D015897:Comorbidity; D016001:Confidence Intervals; D003404:Creatinine / Q000097:blood; D055316:Cystatin C; D015891:Cystatins / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D007674:Kidney Diseases / Q000175:diagnosis / Q000453:epidemiology*; D007677:Kidney Function Tests; D008297:Male; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D017678:Sex Distribution; D016019:Survival Analysis
D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D003404:Creatinine