MMP9 and atherosclerosis: Significantly lower level of this biomarker is registered in the stage AS1/2 of atherosclerosis in PD patients (374.8 (346.4–397.7) ng/mL) compared to the CKD patients treated conservatively (425.2 (405.5–439.5) ng/mL) (P < 0.05), whereas in stage AS3 serum MMP-9 concentration was significantly higher in PD patients in comparison with other CKD patients (P < 0.05).