老年人血清胱抑素C水平升高与亚临床动脉粥样硬化的关系

Association of increased serum Cystatin C level with subclinical atherosclerosis in elderly people

目的：研究老年人血清胱抑素C（Cys C）水平与亚临床动脉粥样硬化（As）的关系,探讨其在冠心病临床应用中的价值.方法：采用横断面调查方法,对收集的老年体检人群472例进行问卷调查、体格检查、血液检查和颈动脉B型超声检测,颈动脉内膜中层厚度（cIMT）和颈动脉斑块作为评价亚临床As的指标,测定血清胱抑素C水平,分析其于cIMT和颈动脉斑块的关系.结果：472例老年体检人群血清Cys C浓度呈偏态和正态分布（偏度2.23,峰度12.33）,男性的Cys C水平[0.66 （0.51 ～0.80）mg/L]显著高于女性[0.58 （0.48～0.69） mg/L,P＜0.001].高水平血清Cys C四分位数组较低水平组的颈动脉内中膜厚度和斑块比例显著增加且呈量效关系（P＜0.001）,cIMT增厚组和斑块组的Cys C水平显著高于正常组（P＜0.001）.血清Cys C水平与年龄、cIMT、BMI、TG、hs-CRP、尿素、尿酸和肌酐显著正相关（P＜0.01）,与TC、HDL-C和肌酐清除率显著负相关（P＜0.05）.多因素Logistic回归分析发现Cys C不是老年人cIMT和颈动脉斑块的独立危险因素（P＞0.05）；年龄、高血压和尿素水平升高是cIMT增厚的独立危险因素,而吸烟史和高血压是颈动脉斑块的独立影响因素.结论：老年人血清Cys C升高可能是随着增龄而导致的肾功能下降、凝血、血压变化所致,并不直接影响亚临床As的发生发展.

Objective： To investigate the association between serum Cystatin C （Cys C） and subclini- cal atherosclerosis in elderly people. Methods ： The cross-sectional study was undertaken on 472 elderly people selected at random from the participants in a physical examination. The medical histot-y of each participant was obtained by questionnaire. The samples of venous blood and the Bilateral B-mode carotid artery images were taken. The association of serum Cys C with carotid intima-media thickness （cIMT） and carotid plaque, the markers of subclinical atherosclerosis （As）, were analyzed. Results： The levels of Cys C showed skewed and leptokurtic distribution （skewness： 2. 23; kurtosis： 12. 33）. Males [0. 66 （0. 51 -0. 80） mg/L] had signifi- cantly higher values of Cys C than females [0. 58 （0. 48 -0. 69） mg/L, P 〈0. 001 ]. eIMT and proportion of carotid plaques in the highest quartile of serum Cys C were significantly higher than that in the lowest quartile, and the increased level in parallel with dose-effect relationship, P 〈 0. 001. The levels of Cys C in the increased cIMT group or the carotid plaque group were significantly higher than the control group （ P 〈 0. 001 ）. SerumCys C were positively correlated with age, cIMT, BMI, TG, hs-CRP, urea, uric acid and creatine （P 〈 O. 01 ） , but negatively correlated with TC, HDL-C and creatinine clearance rate （ P 〈 O. 05 ）. The muhifactor logistic regression analysis showed that serum Cys C were not the independent risk factor, while age, hyperten- sion and the increased level of urea were the independent risk factors for increased clMT and smoke history and hypertension were the independent risk factors for carotid plaques. Conclusion： The increased level of serum Cys C in elderly people may be caused by aging which leads to the injury of kidney function, blood clotting and blood pressure variation, and it has no direct effect on the development of subclinical As.