Relationship Between Serum Leptin Levels And Coronary Microvascular Dysfunction In Relevant Patients

Objective:To study the relationship between serum leptin levels and coronary microvascular dysfunction and the influence of related risk factors for coronary microcirculatory by comparing the index of microcirculatory resistance(IMR)of coronary artery with serum leptin levels,insulin resistance index and other clinical indicators,providing some evidence for making more rational decisions on early diagnosis and prevention of coronary microvascular dysfunction(CMD).Methods:In this retrospective study,cases were collected from the Second Affiliated Hospital of Kunming Medical University from January 2017 to March 2018.A total of 53 patients with the epicardial coronary stenosis below 50%(<50%)through Coronary angiography due to repeated chest tightness and chest pain and IMR greater than or equal to 32(≥32)[1-2]through measurement of Coronary microcirculation resistance index were chose as IMR-elevated group,and 31 with stenosis below 50%and IMR less than 32(<32)were chose as IMR-normal group.The data of fasting blood glucose(FBG),fasting insulin(FINS),and blood-lipid were collected from the morning of the second day after admission of all selected subjects.Serum leptin concentrations were determined in each group using enzyme-linked immunosorbent assay(ELISA).The patient’s insulin resistance was assessed using the homeostasis model insulin resistance index(HOMA-IR),HOMA-IR=FINS*FBG/22.5[3].The IMR values of the patients were measured using the pressure-temperature guide wire technique with a critical value of 32(IMR=32)[1-2].As for the basic clinical data and the intergroup differences between the various examination indicators in each group of patients,we analyzed its relevant factors using Pearson’s or Spearman’s rank correlation analysis,and evaluated the predictive value of serum leptin levels and HOMA-IR for coronary microcirculation using the receiver operating characteristic curve(ROC curve).Results:1.Based on basic clinical data and clinical examination indicators in the IMR-elevated group and the IMR-normal group,there was a statistically significant difference(P<0.05)between two groups in Leptin,HOMA-IR,smoking,hypertension,diabetes,FINS and BMI.2.The correlation analysis of risk factors affecting coronary microvascular dysfunction was analyzed,and correlations between risk factors and IMR were analyzed using Pearson and Spearman,which showed that serum Leptin and IMR(r=0.820,P<0.001)were positively correlated,and so were HOMA-IR and IMR(r=0.529,P<0.001),smoking and IMR(r=0.224.P=0.041),hypertension and IMR(r=0.223.P=0.041),diabetes and IMR(r=0.227.P=0.038),FINS and IMR(r=0.560.P<0.001),FBG and IMR(r=0.239.P=0.029),BMI and IMR(r=0.246.P=0.024),WHR and IMR(r=0.393.P<0.001),PLT and IMR(r=0.402,P<0.001),MPV and IMR(r=0.089,P=0.041).3.In our research,we found that Leptin and IMR(r=0.820,P<0.001)were positively correlated,and correlations between risk factors and Leptin were analyzed using Pearson and Spearman,which showed that FINS and Leptin(r=0.355,P=0.001)were positively correlated,and so were HOMA-IR and Leptin(r=0.307,P=0.005),BMI and Leptin(r=0.284,P=0.009),WHR and Leptin(r=0.353,P=0.001),PLT and Leptin(r=0.325,P=0.003)4.The serum leptin levels and the ROC curve analysis of HOMA-IR in patients with CMD suggested that the area under the diagnostic curve of Leptin and HOMA-IR for CMD was statistically significant(P<0.001 for both).The area under the curve individually were:0.923,0.839.5.Associated risk factors for coronary microcirculation dysfunction entered the binary logistic regression analysis,namely,the dependent variable was "Whether to have coronary microcirculation dysfunction",and the independent variables that covered Age,sex,drinking,.smoking,hypertension,diabetes,FBG、FINS、HOMA-IR、BMI、WHR、TC、TG、LDL-C、HDL-C、CRP、PLT、MPV、Leptin entered the regression model.Finally,Leptin and HOMA-IR remained in the model,and the regression coefficient was positive.The corresponding OR value was greater than 1(>1),indicating that Leptin and HOMA-IR were the independent risk factors for CMD.Conclusion:1.The occurred and development of coronary microcirculation dysfunction and Leptin were positively correlated.2.Serum leptin levels and HOMA-IR are of certain value in predicting CMD,however FINS,BMI,WHR and PLT may affect Leptin’s prediction results.3.Leptin and HOMA-IR are independent risk factors for CMD.4.The occurrence of CMD may also be associated with smoking,hypertension,diabetes,FINS,BMI and MPV.