Improvement of arterial stiffness and myocardial deformation in patients with poorly controlled diabetes mellitus type 2 after optimization of antidiabetic medication
Abstract
Background: Arterial stiffness is associated with increased risk for cardiovascular disease. The purpose of this study is to investigate the arterial stiffness and myocardial deformation in patients with poorly controlled diabetes mellitus type 2 before and after glycemic control by optimal medication.
Methods: In 50 patients with uncontrolled type 2 diabetes(age:52±10years)and 25 controls of similar age and sex and no atherosclerotic risk factors we measured at baseline and 6 months after glycemic control a) carotid-femoral pulse wave velocity(PWVc m/sec-Complior SP ALAM),central systolic blood pressure(cSBP -mmHg),augmentation index(AI%), of the aortic pulse wave(ArteriographTensioMed) b)S’,E'(m/sec)andE’/A’of mitral annulus by Tissue Doppler c)LV longitudinal strain(GLS-%),systolic(LongSr-l/sec)and diastolic(LongSrE-l/sec)strain rate, twisting(Tw-deg),peak twisting(Tw)and untwisting(unTw-deg/sec)velocity using speckle tracking echocardiography.The degree of LV untwisting was calculated as the percentage difference between peak twisting and untwisting at MVO(%dp PeakTw-UntwMVO)and between peak twisting and untwisting at peak and end of the mitral inflow E wave d)perfusion boundary region(PBR- micrometers)of the sublingual arterial microvessels(ranged from 5-25 micrometers)using Sideview,Darkfield imaging(Microscan,Glycocheck).Increased PBR is considered an accurate index of reduced endothelial glucocalyx thickness because of a deeper RBC penetration in the glucocalyx e) Flow mediated dilatation(FMD) of the brachial artery and percentage difference of FMD (FMD%).
Results: Compared to controls,diabetics had higher PWVa(10.3±2.2 vs. 8.1±1.9), AI(27.9±15 vs. 19.4±14.7), PWVc(11.8±3.2 vs. 8.8±1.3),cSBP(136±20 vs. 119±18),PBR (2.1±0.2 vs 1.89±0.1)and lower GLS(-15±3 vs. -18±3),LongSr(-0.78±0.1 vs. -0.96±0.2),LongSrE(0.77±0.29 vs. 1.2±0.3),S’,E’ and E/A(p<0.05 for all comparisons). Baseline FMD was related with Untw at peak E%(r=0,65, p<0.05). Six months after the modification of antidiabetic medication all patients achieved glycaemic control and there was a reduction of PWVc(12.3±2.9 vs. 11.3±3.2,p<0.05) in parallel with a increase of Untw velocity (-73±27 vs. -98±43,p<0.05),Untw MVO%(20±9 vs. 30±2),Untw peak E% (40±14 vs. 50±16)and FMD%(7.8±3 vs. 13.6±11,p<0.01).Reduced PWVc was related with reduced SBP(r=0.62),cSBP(r=0.55)and increased LongsrE(r=-0.50), Untw at end E(r=-0.56)respectively(p<0.05 for all associations).
Conclusion: Glycaemic control after optimizing medical treatment improves arterial stiffness, LV myocardial strain, twisting and untwisting velocity in diabetics.