P0737THE ASSOCIATION BETWEEN CYSTATIN C AND ARTERIAL STIFFNESS IN NON-CKD PATIENTS

Abstract

Abstract Background and Aims Serum cystatin C (cysC) is produced by all nucleated cells at a constant rate, is filtered freely by the glomerulus and metabolized after tubular reabsorption. It is influenced less by age, gender and muscle mass compared to serum creatinine. These properties make it an important marker in detecting renal impairment. Arterial stiffness is a hallmark of atherosclerosis and is connected to cardiovascular events and mortality. In patients with chronic kidney disease (CKD), cysC correlates with increased arterial stiffness, but less is known about the association between cysC and arterial stiffness in non-CKD patients. Method The study was performed at the University Medical Centre Maribor between October 1st 2018 and January 1st 2020. Basic demographic and laboratory data were recorded. To estimate glomerular filtration rate (eGFR), Chronic Kidney Disease Epidemiology (CKD-EPI) equation was used. Patients with previously diagnosed CKD and/or eGFR ≤ 60 ml/min/1.73m2 at the time of admission, known malignancy, thyroid disease and/or on steroid therapy were not enrolled in the study. Arterial stiffness was measured with applanation tonometry (Sphygmocor®, Australia), carotid-femoral pulse wave velocity (cfPWV) was used as the gold standard of central arterial stiffness and subendocardial viability ratio (SEVR) was used as the marker of myocardial perfusion. SPSS® version 22 was used for statistical analysis. Results 111 patients (65.8% male, average age 64.3±9.4 years) were included in our study. Most common comorbidities were arterial hypertension (n=86, 77.5%), hyperlipidaemia (n=64, 57.7%) and diabetes mellitus (n=22, 19.8%). Mean creatinine value was 77.7±13.8 μmol/L (range 49-108 μmol/L), mean eGFR was 81.3±9.4 ml/min/1.73m2 (range 62-90 ml/min/1.73m2) and mean value of cysC was 0.94±0.18 mg/L (range 0.67-1.63 mg/L). Mean SEVR value was 165.7±36.1% (range 92-299%) and mean cfPWV value was 10.1±2.4 m/s (range 6.2-16.8 m/s). Significant correlation was found between cysC and SEVR (r=-0.316, p<0.001) and between cysC and cfPWV (r=0.472, p<0.001). Multiple regression analysis of arterial stiffness indices and cysC, age, gender, diabetes mellitus, arterial hypertension, eGFR and hyperlipidemia, showed statistically significant association between cysC and cfPWV (ß=0.220, p=0.038) and cysC and SEVR (ß=-0.278, p=0.017). Conclusion Serum cysC is independently associated with increased arterial stiffness, reduced myocardial perfusion and increased cardiovascular risk in non-CKD patients.