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.