Cystatin C and arterial stiffness in patients without chronic kidney disease.

Abstract

Cystatin C (cysC) is freely filtered in the glomeruli, and its serum concentration is independent of muscle mass, diet, gender, or age. In patients with chronic kidney disease (CKD), cysC is associated with advanced atherosclerosis and increased arterial stiffness. The purpose of this study was to define possible associations between arterial stiffness parameters and cysC in patients without CKD. The study included 111 non-CKD patients. Basic demographic and laboratory data were recorded. Arterial stiffness was measured by applanation tonometry (sphygmocor, Australia). Mean age of the patients was 64.3 ± 9.4 years, 65.8% were men. Most common co-morbidities were arterial hypertension (AH) (n = 86, 77.5%), hyperlipidemia (n = 64, 57.7%), and diabetes mellitus (DM) (n = 22; 19.8%). Mean creatinine was 77.7 ± 13.8 µmol/L (range 49 - 108), estimated GFR 81.3 ± 9.4 mL/min/1.73m2 (range 62 - 90), and cysC 0.94 ± 0.18 mg/L (range 0.67 - 1.63). Mean carotid-femoral pulse wave velocity (cfPWV) was 10.1 ± 2.4 m/s (range 6.2 - 16.8), subendocardial viability ratio (SEVR) 165.7 ± 36.1% (range 92 - 299), ejection duration (ED) 33.8 ± 4.4 ms (range 22 - 46), and pulse pressure (PP) 46.6 ± 14.8 mmHg (range 17 - 94). A statistically significant association was found between cysC and cfPWV (r = 0.472, p < 0.001), SEVR (r = -0.316, p < 0.001), ED (r = 0.217, p = 0.025), and pulse pressure (PP) (r = 0.241, p = 0.012). Multiple regression analysis between arterial stiffness parameters and cysC, age, male gender, AH, DM, hyperlipidemia, and eGFR confirmed a statistically significant and independent association between cysC and cfPWV (β = 0.220, p = 0.038), between cysC and SEVR (β = -0.278, p = 0.017), and between cysC and ED (β = 0.241, p = 0.045). Elevated cysC is associated with increased cfPWV, increased ED, and decreased SEVR.