Evaluation Of Left Ventricular Systolic Function And Analysis Of Plasma Exosomal MiRNA Expression Profile In Obese Patients

Part Ⅰ Evaluation of left ventricular systolic function in obese patients by three-dimensional speckle tracking imagingObjective Application of three-dimensional speckle tracking imaging(3D-STI)to assess left ventricular systolic function in obese patients.Methods In this study,16 obese patients and 27 healthy adults were screened and included in the obese and normal groups,and routine echocardiography and 3D-STI examinations were performed on all subjects.The general clinical data,conventional echocardiography,and 3D-STI indexes were compared between the normal and obese groups,and the correlation between the 3D-STI indexes and general clinical data was analyzed.Results1.Compared to the normal group,the obese group had significantly higher levels of BMI,diastolic blood pressure,CHOL,TG,and LDL,and significantly lower levels of HDL,with statistical significance(P < 0.05).There were no statistically significant differences in gender,age,systolic blood pressure,heart rate,and GLU between the two groups(P > 0.05).2.Compared to the normal group,the obese group had significantly higher levels of IVSD and LVPWD,with statistical significance(P < 0.05).There were no statistically significant differences in LVEDD,LVESD,LVEF,E,A,E/A,e’,and E/e’ between the two groups(P > 0.05).3.Compared to the normal group,the obese group had significantly lower levels of left ventricular GLS,GCS and GRS,with statistical significance(P < 0.01).There were no statistically significant differences in LVEDV and LVESV between the two groups(P >0.05).4.There were negative correlations between left ventricular GLS,GCS,GRS and body weight(r=-0.486,-0.388,-0.574,P < 0.05);between GLS,GCS,GRS and BMI(ρ=-0.620,-0.424,-0.656,P < 0.05);between GLS,GCS,GRS and diastolic blood pressure negative correlation(r =-0.620,-0.646,-0.751,P < 0.001);between GLS,GRS and LDL(r =-0.436,-0.366,P < 0.05);and between GLS,GCS,GRS and HDL(ρ = 0.520,0.309,0.453,P < 0.05);There was no correlation between GLS,GCS,GRS and gender,age,height,systolic blood pressure,GLU,CHOL,TG(P > 0.05).Conclusion GLS,GCS,and GRS obtained by 3D-STI can sensitively detect subclinical left ventricular systolic dysfunction in obese patients.and it is more severe with increased BMI,diastolic blood pressure,LDL and decreased HDL.Part Ⅱ Extraction and identification of plasma exosomes and miRNA expression profiling analysis in obese patientsObjective Bioinformatic analysis of plasma exosomal miRNA expression profiles in obese patients was performed to explore the mechanisms of obesity-related myocardial injury at the exosomal miRNA level.Methods Plasma exosomes were extracted from three normal group samples and three obese group samples by ultracentrifugation and identified by transmission electron microscopy and nanoparticle tracking analysis.Plasma exosome miRNA expression profiles were obtained by sequencing,and differentially expressed miRNAs were screened for target gene prediction and enrichment analysis.Results1.The circulating exosomes were successfully extracted,and the typical bilayer membrane structure was observed by transmission electron microscopy.The nanoparticle tracking analysis showed stable particle size and concentration.2.Compared with the normal group,there were 59 significantly different miRNA in the obese group,including 33 up-regulated miRNA and 26 down-regulated miRNA(P < 0.05),of which 6 were newly predicted miRNA;among the significantly up-regulated miRNA,miR-101-3p,miR-106b-3p,miR-140-3p,miR-142-5p,and miR-99a-5p were expressed at high levels.3.By further bioinformatic analysis,these differential miRNAs were found to be involved in many biological processes and pathways.Important miRNA,including miR-101-3p,miR-140-3p,and miR-99a-5p,have clinical value in predicting early obesity-associated myocardial injury;differential miRNA may regulate obesity-associated ventricular remodeling,neovascularization,and myocardial fiber formation through the PI3K-Akt signaling pathway.Conclusion Compared with those of healthy adults,the plasma exosomal miRNA expression profiles of obese patients are significantly different,and differential miRNAs are involved in many biological processes and signaling pathways.The key miRNA and signaling pathways provide an important theoretical basis and targets for the study of obesity-related myocardial injury.