Plasma cystatin-C and development of coronary heart disease: The PRIME Study.

The pathogenesis of ischemic coronary events involves degradation of the extracellular matrix in atherosclerotic lesions. The cysteine protease inhibitor cystatin-C may be involved in this phenomenon. The association of plasma cystatin-C with the incidence of myocardial infarction-coronary death and angina, was examined in a nested case-control (two controls per case) design within the prospective cohort study (Prospective Epidemiological Study of Myocardial Infarction (PRIME Study)) which included 9,758 men aged 50-59 years who were free of coronary heart disease (CHD) on entry and followed for a 5-year period. Three hundred and thirteen participants suffered myocardial infarction or coronary death (n = 159) or angina pectoris (n = 154) during follow-up. Cystatin-C was positively correlated with body mass index (BMI), low-density lipoprotein (LDL)-cholesterol, triglycerides and several inflammatory markers such as fibrinogen (r = 0.18), C-reactive protein (CRP) (r = 0.24), interleukin-6 (= 0.20), tumor necrosis factor-alpha (TNFalpha) (r = 0.27) and two TNFalpha receptors: TNFR1A (r = 0.43) and TNFR1B (r = 0.41); and negatively with high-density lipoprotein (HDL)-cholesterol (r = -0.25). After adjustment for traditional risk factors (age, diabetes, smoking, hypertension, BMI, triglycerides, LDL- and HDL-cholesterol), cystatin-C was significantly associated with the occurrence of the first ischemic coronary event. However, this association was no longer significant when CRP was included in the analysis. A decrease in glomerular filtration rate did not explain higher cystatin-C in cases than in controls. Cystatin-C appears to participate in the inflammatory phenomenon observed in the atherosclerotic process. Cystatin-C is not a more predictive risk marker of CHD than CRP or interleukin-6, but could be useful in detecting moderate chronic renal disease.