Association Between Serum Cystatin C And Carotid Atherosclerosis In Healthy Adults Seeking Physical Examinations

Objectives It is purposed to study the association between serum cystatin C (CysC) and carotid atherosclerosis (CA), based on the data from physical examinations for healthy adults at a large hospital in Beijing, and the changes of serum CysC level in healthy adults of both sex with varied ages and its value to predict carotid atherosclerosis.Methods Records of1741healthy adults aged18years and over,1193men and548women, who sought physical examinations at the Peking Union Medical College Hospital during January2010to December2011were collected for analysis, excluding those with chronic diseases, such as hypertension, diabetes, liver insufficiency, renal insufficiency, tumor, thyroid disease, and so on. Items examined included routine physical checks-up (body height, weight, blood pressure, etc.), determinations of serum levels of CysC and other biochemical indicators [fasting blood glucose (FBG), total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), total bilirubin (TBil), direct bilirubin (DBil), uric acid (UA), liver function, renal function, etc.], duplex ultrasonographic scanning for the intima-media thickness (IMT) of the carotid artery, abdominal B-mode ultrasonographic scanning, chest radiography, etc. Based on the results of carotid duplex ultrasonography, all the people checked were divided into two groups, one with thickened intima-media or formation of atherosclerotic plaque (AP) in the wall of the carotid artery, and the other without it. Difference in serum levels of CysC and other biochemical indicators between the two groups was analyzed with t-test. Associations between serum CysC with some relevant factors were analyzed with Pearson correlation. Factors related to the thickened intima-media or formation of AP were analyzed with unconditional logistics regression.Results (1)Serum levels of CysC, blood urea nitrogen (BUN), creatinine (Cr), TC, LDL-C, UA and FBG were all significantly higher in the group with thickened carotid intima-media or with AP than those in the group without it (P<0.05), respectively. There was no significant difference in serum level of TBil, DBil, TG and HDL-C between the two groups (P>0.05), respectively.(2) Serum level of Cys C positively correlated with age, blood pressure, BMI, serum levels of Cr and UA, respectively (P<0.05). There was no significant association between serum levels of Cys C and FBG, TC, TG, TBil and DBil, respectively(P<0.05).(3) Serum level of CysC increased with age in those aged50years or over (x=179.951,P<0.01)(4) Serum level of CysC was significantly higher in men [(0.8623±0.13091) mg/L] than that in women [(0.7630±0.13873) mg/L](P<0.01), except for those aged30years or less.(5) Results of multivariate logistic regression analysis showed that gender, age and low-density lipoprotein-cholesterol level significantly correlated with CA (P<0.05), but it is uncertain whether serum level of CysC is an independent factor related to CA.Conclusions (1) Association of serum level of CytC with CA has not been confirmed in healthy adults seeking physical examinations and should be studied further by cohort design.(2) Serum level of CysC varies by age and gender, is higher in men than that in women, and increases with age in those aged50years or more.