Correlation Between Serum Cystatin C And Vascular Damage In Essential Hypertensive Patients

Objective: The paper observes the changes of serum cystatin C(Cys C)level and vascular damage in essential hypertensive(EH)patients,analyzes the correlation between serum Cys C level and vascular damage in EH patients,and explores the predictive value of serum Cys C level in judging different vascular damage in EH patients,so as to provide clinical guidance for early detection and treatment of vascular damage in EH patients.Methods: A total of 651 cases of EH patients were selected from January 2017 to October 2019 in the cardiology of the Second Hospital of Dalian Medical University with an average age of 59.78 ±13.07 years.The general data of age,sex and medical history were recorded,and the biochemical indexes such as serum Cys C,fasting blood glucose(FBG),total cholesterol(TC),triglyceride(TG),high density lipoprotein cholesterol(HDL-C),aspartate aminotransferase(AST),total bilirubin(TB),creatinine(Cr),uric acid(UA)and were recorded.Carotid intima-media thickness(c IMT)was measured by carotid artery color Doppler ultrasound.The brachial-ankle pulse wave velocity(ba PWV)and ankle-brachial index(ABI)were measured by non-invasive peripheral blood vessels.The abnormalities of c IMT,ABI and ba PWV were defined as vascular damage.Patients were divided into 4 groups according to the quartile of serum cystatin C,including 164 cases of Q1(Cys C ? 0.85mg/L),169 cases of Q2(0.85mg/L< Cys C ? 0.95mg/L),161 cases of Q3(0.95 mg/L< Cys C ? 1.07mg/L),157 cases of Q4(Cys C> 1.07mg/L).The differences of general data and the c IMT,ABI and ba PWV among the four groups were compared.To explore the correlation between serum Cys C level and vascular damage index c IMT,ABI,ba PWV,biochemical index FBG,TC,Cr,UA and cardiac structure related index LAD,IVST.To explore the independent influencing factors of different vascular damage in EH patients by stepwise linear regression analysis.The ROC curve of serum Cys C was analyzed to explore the evaluation significance of this index for the abnormalities of c IMT,ABI and ba PWV.Results:1.Patients were divided into 4 groups by the quartile of Serum Cys C level: Q1,Q2,Q3 and Q4.The results showed that with the increase of serum Cys C level,the level of c IMT,ba PWV increased(trend test,P<0.05),the level of ABI decreased(trend test,P<0.05).The levels of c IMT and ba PWV in Q4 group were higher than those in Q1,Q2 and Q3 groups,and the differences were statistically significant(P<0.05),there were no statistically significant difference in c IMT and ba PWV among Q1,Q2 and Q3 groups.The ABI of Q4 group was lower than that of Q1,Q2 and Q3 groups,and the differences were statistically significant(P<0.05),there were no statistically significant difference in ABI among Q1,Q2 and Q3 groups.2.The results of correlation analysis showed that serum Cys C was positively correlated with age,Cr,UA,c IMT,ba PWV,LAD and IVST(r = 0.319,r = 0.486,r =0.254,r = 0.246,r = 0.242,r = 0.234,r = 0.172,P < 0.05),was negatively correlated with ABI(r =-0.175,P < 0.05),but not correlated with FBG and TC.3.Stepwise linear regression analysis showed that the increase of serum Cys C in EH patients was an independent risk factor of c IMT thickening,ba PWV increasing and ABI decreasing.4.Using c IMT,ABI and ba PWV as working variables,the serum Cys C as ROC curve,the critical value of c IMT thickening according to ROC curve was 0.965mg/L(area under curve 0.612,sensitivity 53.3%,specificity 65.6%);the critical value of ABI reduction according to ROC curve was 1.015mg/L(area under curve 0.624,sensitivity57.8%,specificity 67.8%);the critical value of ba PWV acceleration according to ROC curve was 0.965mg/L(area under curve 0.584,sensitivity 49.0 %,specificity 64.4%).Conclusion: 1.The level of serum Cys C is positively correlated with the degree of vascular damage in EH patients,the level of serum Cys C was high,the degree of vascular damage increased.2.Stepwise linear regression analysis showed that the increase of serum Cys C level was an independent risk factor of c IMT thickening,ba PWV increasing and ABI decreasing.3.The level of serum cystatin C had a certain clinical value in judging different vascular damage in EH patients.When serum Cys C >0.965mg/L,the specificity of diagnosing c IMT thickening in EH patients was 65.6%.When serum Cys C >1.015mg/L,the specificity of ABI decrease in EH patients was 67.8%.When serum Cys C>0.965mg/L,the specificity for the diagnosis of increased ba PWV in EH patients was64.4%,but the sensitivity were slightly lower.