Enhanced External Counterpulsation (EECP) Improves Peripheral Artery Function

27 BackgroundIn coronary artery disease patients, enhanced external counterpulsation (EECP) 28 improves peripheral arterial function and nitric oxide (NO) bioavailability, which have been 29 implicated in the pathogenesis of abnormal glucose tolerance (AGT). We sought to evaluate the 30 effects of EECP on outcomes of arterial function, glucose tolerance, and skeletal muscle 31 morphology in subjects with AGT. 32 Methods and ResultsEighteen subjects with AGT were randomly (2:1 ratio) assigned to receive 33 either 7 weeks (35 1-hour sessions) of EECP (n = 12) or 7-weeks of standard care (control; n = 34 6). Peripheral vascular function, biochemical assays, glucose tolerance, and skeletal muscle 35 morphology were evaluated before and after EECP or control. EECP increased normalized 36 brachial artery (27%) and popliteal artery (52%) flow-mediated dilation. Plasma nitrite/nitrate 37 (NOx) increased (30%) and, 8-isoprostane-PGF-F2α, a marker of lipid peroxidation in the 38 plasma, decreased (-23%). Fasting plasma glucose declined (-16.9 ± 5.4 mg/dL) and the 39 homeostasis model assessment of insulin resistance (HOMA-IR) decreased (31%) following 40 EECP. Plasma glucose 120 minutes after initiation of oral glucose tolerance testing decreased (41 28.3 ± 7.3 mg/dL) and the whole-body composite insulin sensitivity index (C-ISI) increased 42 (21%). Vascular endothelial growth factor (VEGF) concentrations increased (75%) and vastus 43 lateralis skeletal muscle biopsies demonstrated improvements in capillary density following 44 EECP. No change was observed in cellular signaling pathways, but there was a significant 45 increase GLUT-4 protein expression (47%) following EECP. 46 ConclusionsOur findings provide novel evidence that EECP has a beneficial effect on 47 peripheral arterial function and glucose tolerance in subjects with AGT. 48 KeywordsVascular function, glycemic control, diabetes, capillary density 49 by 10.0.33.3 on O cber 5, 2017 http://jaysiology.org/ D ow nladed fom