SERUM CREATININE AND CORONARY MORTALITY IN THE ELDERLY WITH NORMAL RENAL FUNCTION: THE CARDIOVASCULAR STUDY IN THE ELDERLY (CASTEL)

BACKGROUND: Elevated serum creatinine (SCr) levels have been associated with increased mortality. Aim of this study is to evaluate whether SCr independently predicts coronary heart disease (CHD) mortality in a population of elderly with SCr values within the normal range. METHODS: Three thousand two hundred and fifty-seven men and women aged > or = 65 years were recruited in the population-based frame. Historical and clinical data, blood tests and 12-year fatal CHD events were recorded. SCr and creatinine clearance (Crcl) were divided into tertiles and, for each tertile, gender-specific adjusted relative risk (RR) with 95% confidence intervals (CI) for CHD mortality was calculated. RESULTS: Both SCr and Crcl independently predicted CHD in men but not in women. In men CHD mortality increased with increasing SCr tertiles, being 1.5%, 5.5% (RR 2.51, CI 1.01-4.93) and 7.7% (RR 3.50, CI 1.41-5.88), respectively. The relationship between Crcl and CHD was inverse and increased with decreasing Crcl [2.7%, 3.3% (RR 1.42, CI 0.74-2.26) and 6.7% (RR 2.78, CI 1.56-4.12) in the 3rd, 2nd and 1st tertiles, respectively]. CONCLUSIONS: SCr independently predicts CHD mortality in elderly men, but not in women. The increased CHD risk observed for SCr levels within the normal range is probably due to a sub-clinical impairment of renal function.