| Objective:Type 2 diabetes mellitus（T2DM）and obesity are both growing epidemics worldw ide,and both are independently associated with an increased risk of heart failure and death.Whether the dual factors of T2DM and obesity further increase the degree of left ventricular dysfunction in patients is not clearly established.The aim of this study was to assess the combined effects of T2DM and increased body mass index（BMI）on left ventricular myocardial systolic and diastolic function using conventional echocardiog raphy combined with two-dimensional speckle tracking echocardiography（2DSTE）.Methods:One hundred and fifty patients with T2DM who were hospitalized at the Departme nt of Endocrinology and Metabolism,Fengxian District Central Hospital,Anhui Unive rsity of Science and Technology,from January 2020 to August 2021 and 60 healthy controls matched for age,sex and BMI during the same period were selected for the study.The study subjects were grouped according to the Expert Consensus and Group Standards for Quality Management of Overweight or Obese People Groups:Normal(18.5≤BMI<24kg/m2),Overweight（24≤BMI<28kg/m2）,and Obese（BMI≥28kg/m2）.The left ventricular ejection fraction（LVEF≥55%）in all study subjects.In this study,conventional echocardiography combined with 2DSTE was used to assess the parameters of left ventricular systolic function:left ventricular-global longitudinal strain（LVGLS）and systolic longitudinal strain rate（LSRs）;parameters used to assess LV diastolic function The ratio of early diastolic peak velocity（E）to early diastolic tissue velocity（e’）（E/e’）and early-diastolic longitudinal strain rate（LSRe）.（1）Bland-Altman test plots were used to show the inter-and intra-observer agreement of LVGLS,LSRs,and LSRe measurements.（2）To compare the changes in left ventricular systolic function（LVGLS,LSRs）and left ventricular diastolic function（E/e’,LSRe）with increasing BMI levels in T2DM patients.（3）To compare the changes in LVGLS,LSRs and E/e’and LSRe with increasing BMI levels between the control and T2DM groups.（4）To analyse the correlation between BMI and LVGLS,LSRs,E/e’and LSRe in each group using Pearson correlation analysis.（5）Independent influences on LVGLS,LSRs,E/e’,and LSRe were analysed using multiple linear regression analysis.（6）A two-factor ANOVA was used to analyse the combined effect of T2DM and Increased BMI levels on LV systolic and diastolic function.Results:（1）Bland-Altman analysis showed that the scatter of inter-and intra-observer LV GLS,LSRs,and LSRe measurements mostly fell within the 95%limits of agreement,suggesting that the present data had a good level of agreement.（2）In patients with T2DM,left ventricular myocardial systolic function and left ventricular diastolic function were progressively impaired as BMI levels increased.（3）Comparisons between groups showed that as BMI levels increased,LV myocardial function was more impaired in the T2DM group than in the control group,with statistically significant differences（P<0.05）.（4）Pearson correlation analysis showed that BMI was negatively correlated with LVGLS,LSRs and LSRe and positively correlated with E/e’in the control group and the T2DM group,and the difference was statistically significant（P<0.05）.（5）Multiple linear regression analysis showed that increased levels of T2DM and BMI were independently associated with impairment of left ventricular myocardial systolic function（LVGLS,LSRs）and diastolic function（E/e’,LSRe）（P<0.05 or P<0.01）.（6）Two-way ANOVA showed an interactive effect of increased levels of T2DM and BMI on LSRe（F=5.424,P=0.005）,with the combination of the two showing a superimposed and interactive effect on the impairment of LV function in patients.Conclusions:1.Patients in the T2DM group with LVEF at normal levels already had reduced LV myocardial systolic and diastolic function,and the degree of impaired LV myocardial systolic and diastolic function further increased with increasing BMI levels.2.Both T2DM and increased BMI levels were independent influences on LV myocardial systolic and diastolic hypokinesis,and increased T2DM and BMI levels had an interactive effect on LSRe,and the impairing effects of both on LV function in patients were shown to be superimposed and interactive.Figure[16]Table[9]Reference[106]. |
