Assessment of Serum Cystatin C as an Early Biomarker of Carotid Atherosclerosis

The aim of this study was to establish the correlation between the value of serum cystatin C (Cys C) and carotid atherosclerosis inpatients without chronic kidney disease and to determine the serum Cys C cut-off level for carotid atherosclerosis diagnosis. The study was performed between October 2014 and June 2018, and included 256 patients from 20 family medicine offices of Timis County, both from urban and rural areas. The patients completed a socio-demographic questionnaire, and were clinically examined by their general practitioner and investigated by laboratory tests and carotid ultrasound. The mean age of the patients with high serum Cys C (study group 1) was 74 years (82% male), while in study group 2 (with low serum Cys C values) the mean age was 56 years old (63% male). Cys C levels were significantly correlated with serum creatinine and estimated glomerular filtration rate. In the group with elevated levels of Cys C we found an increased incidence of obesity, hypertension, diabetes and carotid atherosclerosis. Multivariate analysis showed that the increased levels of Cys C were associated with a maximum carotid plaque thickness (MCPT) >= 2 mm (OR: 2.86, 95% C.I.: 1.13-7.97). The serum Cys C cut-off level for the diagnosis of atherosclerosis determined by ROC (receiver operating characteristic) curve was 0.73 mg/dL.