Changes Of Heart Structure And Function In Patients With Type 2 Diabetes Mellitus

Objective To study the changes of heart structure and function in patients with type 2 diabetes mellitus(T2DM).Methods Ninety consecutive patients with T2DM were divided into T2DM group 1 (urinary albumin excretion rate(UAER)<20ug/min, n:52) and T2DM group 2(UAER>20ug/min, n:38). Twenty six age and sex-matched healthy people were selected as controls. Echocardiograms were performed by use of the methods recommended by American Society of Echocardiography and European Association of Echocardiography in 2005 and 2009. Glycated hemoglobin(HbA1c), plasma N-terminal B-type brain natriuretic peptide(NT-proBNP), blood urea nitrogen, creatinine and other relevant laboratory indexes were tested.Results Interventricular septal thickness(IVSTd), posterior wall thickness(PWTd), relative wall thickness(RWT), left ventricular mass(LVM) and LVM index(LVMi), left atrial dimension(LAD) and LAD index(LADi), left atrial volume(LAV)and LAV index(LAVi), right atrial long axis dimension(RA-D2), pulmonary arterial diameter(PA) were increased in both T2DM group 1 and T2DM group 2 compared with control group(P<0.05-<0.01). But left ventricular end diastolic volume(LVEDV), LVEDV index(LVEDVi), right atrial area(RA-A) showed increment only in T2DM group 2 compared with control group(P<0.05-<0.01). Furthermore, PWTd, LVM, LVMi, LVEDV, LVEDVi, LAD, RA-D2, and RA-A of T2DM group 2 were greater than those of T2DM group 1(P<0.05-<0.01). Both PWTd and LAD were positively correlated with age, body mass index(BMI), waist circumference, hip circumference, UAER, and NT-proBNP. IVSTd with age, hip circumference, and LVMi with age, UAER, NT-proBNP were positively correlated. RA-D1, RA-D2 and RA-A with NT-proBNP, PA with age, weight, BMI, waist circumference, UAER were also positively correlated.Peak late diastolic mitral inflow velocity(A wave) was increased in both T2DM group 1 and T2DM group 2 compared with control group(P<0.01). Left ventricular ejection fraction(LVEF), peak early diastolic mitral inflow velocity(E wave), E/A ratio, deceleration time(DT) of E wave, A wave duration(durA), isovolumic relaxation time(IVRT), and all the parameters from pulmonary venous flow were no statistically significant difference among the three groups. Early velocities of lateral(E'L) and septal(E's) mitral annulus, and E/E'L ratio were not significantly different among the three groups. E/E's ratio, M-E/E'ratio(average of E/E'L ratio and E/E's ratio) of T2DM group 2 were greater than those of control group(P<0.01). The left ventricular flow propagation velocity(FPV) and E/FPV ratio were not statistically different among the three groups. Peak A with age, blood pressure, HbA1c, duration of diabetes, UAER were positively correlated. E/E's, M-E/E' were positively correlated with age, NT-proBNP, and LAD but negatively with LVEF.Conclusion The major cardiac structural changes of T2DM were left ventricular remodeling/hypertrophy, double atrial enlargement and pulmonary artery broadening, which were related to age, BMI, waist circumference, hip circumference, UAER and NT-proBNP. The major cardiac functional changes of T2DM were left ventricular diastolic dysfunction. With the emergence of diabetic nephropathy, the impairment of diastolic function was more prominent. E/E' was well correlated with NT-proBNP and LAD. But the sensitivity and specificity of E/A, DT, IVRT, FPV were poor.