Elevated cystatin C levels predict the incidence of vasospastic angina.
ABSTRACT Cystatin C, a marker for early stage chronic kidney disease, has been shown to be involved in cardiovascular disease. The relationship between serum cystatin C levels and coronary vasospastic angina (VSA), however, remains to be elucidated. The aim of the present study was to investigate whether elevated cystatin C levels predict the incidence of VSA.
One hundred and ten patients were referred to hospital due to suspected VSA. VSA was evoked in 59 patients by a vasospasm provocation test with administration of acetylcholine into the coronary arteries. The patients with VSA had lower levels of high-density lipoprotein cholesterol and a higher history of cigarette smoking, higher levels of triglyceride, high-sensitivity C-reactive protein, and higher cystatin C levels compared with those without VSA. There were no differences in serum creatinine or estimated glomerular filtration rate between patients with and without VSA. Multivariate logistic regression indicated that history of smoking (odds ratio, 2.956 P<0.05) and cystatin C levels (odds ratio, 2.285; P<0.01) were independently associated with the incidence of VSA.
Elevated cystatin C levels were associated with higher incidence of VSA, suggesting that mild renal dysfunction may be implicated in the pathogenesis of coronary artery spasm.
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ABSTRACT: Although patients with medically treated vasospastic angina have a good outcome, few data exist regarding the role of underlying lesion severity associated with or without hyperlipidemia in the prognosis. Therefore, the aim of the present study was to assess the relationship between the long-term outcome of vasospastic angina and the factors influencing its prognosis. A total of 256 patients (219 men, 37 women; mean age, 54.1+/-9.2) who had coronary spasm with or without underlying lesions and were being treated with calcium channel antagonists were enrolled and followed for 13.6+/-3.7 years. Cardiac events consisted of cardiac death and ischemic events, which included acute myocardial infarction and unstable angina. Cox analysis selected coronary artery stenosis (CAS, >/=50%) and risk factors such as age, hypertension, diabetes mellitus, low-density lipoprotein-cholesterol (LDL-C), sex and smoking. There were 19 cases of cardiac death (7.4%) and 58 of ischemic events (22.7%) during the follow-up period. The presence of significant CAS was an independent predictor of event-free survival (hazard ratio (HR) =2.84, 95% confidence interval (CI) =1.79-4.52, p<0.0001). In 193 patients without significant CAS, there were 10 cases of cardiac death (5.2%, p<0.05) and 34 of ischemic events (17.6%, p<0.01). In that group, high LDL-C was the independent predictor of event-free survival (HR = 3.89, 95% CI = 1.20-12.6, p=0.02). Kaplan-Meier survival analysis revealed significantly lower event-free survival in patients with than in those without lesions (p<0.0001 by log-rank test). These results demonstrate that the most important factor for long-term prognosis of vasospastic angina treated with calcium channel antagonists is significant CAS. High LDL-C, which might alter the underlying coronary endothelial function and/or accelerate atherosclerotic lesions, could also contribute to the occurrence of cardiac events, particularly in patients without significant CAS.Circulation Journal 12/2003; 67(12):1029-35. · 3.58 Impact Factor
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ABSTRACT: Estimation of glomerular filtration rate (GFR) is limited by differences in creatinine generation among ethnicities. Our previously reported GFR-estimating equations for Japanese had limitations because all participants had a GFR less than 90 mL/min/1.73 m2 and serum creatinine was assayed in different laboratories. Diagnostic test study using a prospective cross-sectional design. New equations were developed in 413 participants and validated in 350 participants. All samples were assayed in a central laboratory. Hospitalized Japanese patients in 80 medical centers. Patients had not participated in the previous study. Measured GFR (mGFR) computed from inulin clearance. Estimated GFR (eGFR) by using the modified isotope dilution mass spectrometry (IDMS)-traceable 4-variable Modification of Diet in Renal Disease (MDRD) Study equation using the previous Japanese Society of Nephrology Chronic Kidney Disease Initiative (JSN-CKDI) coefficient of 0.741 (equation 1), the previous JSN-CKDI equation (equation 2), and new equations derived in the development data set: modified MDRD Study using a new Japanese coefficient (equation 3), and a 3-variable Japanese equation (equation 4). Performance of equations was assessed by means of bias (eGFR - mGFR), accuracy (percentage of estimates within 15% or 30% of mGFR), root mean squared error, and correlation coefficient. In the development data set, the new Japanese coefficient was 0.808 (95% confidence interval, 0.728 to 0.829) for the IDMS-MDRD Study equation (equation 3), and the 3-variable Japanese equation (equation 4) was eGFR (mL/min/1.73 m2) = 194 x Serum creatinine(-1.094) x Age(-0.287) x 0.739 (if female). In the validation data set, bias was -1.3 +/- 19.4 versus -5.9 +/- 19.0 mL/min/1.73 m2 (P = 0.002), and accuracy within 30% of mGFR was 73% versus 72% (P = 0.6) for equation 3 versus equation 1 and -2.1 +/- 19.0 versus -7.9 +/- 18.7 mL/min/1.73 m(2) (P < 0.001) and 75% versus 73% (P = 0.06) for equation 4 versus equation 2 (P = 0.06), respectively. Most study participants had chronic kidney disease, and some may have had changing GFRs. The new Japanese coefficient for the modified IDMS-MDRD Study equation and the new Japanese equation are more accurate for the Japanese population than the previously reported equations.American Journal of Kidney Diseases 03/2009; 53(6):982-92. · 5.29 Impact Factor
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ABSTRACT: There is increasing interest in studying the epidemiology of subjects with mild to moderate chronic renal insufficiency (CRI), defined as reduced glomerular filtration rate (GFR) not requiring renal replacement therapy. This review discusses some of the methodological challenges presented by the epidemiological study of mild to moderate CRI that have not been adequately addressed in the literature. Issues that relate to defining the prevalence of CRI include between-laboratory differences in serum creatinine (SCr) assays, within-person measurement errors in SCr, and differences in SCr in different demographic groups that are independent of GFR. Issues that relate to examining CRI as an outcome include the choice between a "slope" or "threshold" analysis. Issues that relate to examining CRI as an exposure include the choice of renal function measure (for example, SCr vs. estimated GFR) in multivariable analysis, whether to normalize renal function to body surface area or other body size parameters, potential effect modification of the association between CRI and the outcome and the complex relation between CRI, adverse outcomes, potential confounders and intermediary variables. As we enter an era of more intensive study of mild to moderate CRI, recognition of these potential pitfalls should guide researchers toward improving the quality of epidemiological research in this field.Kidney International 06/2002; 61(5):1567-76. · 7.92 Impact Factor