Effect of All‐extremity High‐Intensity Interval Training vs. Moderate‐Intensity Continuous Training on Arterial Stiffness and Wave Reflection in Adults with Type 2 Diabetes

Abstract

Aging and type 2 diabetes (T2D) are associated with arterial stiffening and altered wave reflection, which increase the risk for cardiovascular disease (CVD). Aerobic exercise training is known to reduce CVD risk but the most effective exercise regimen for improving arterial stiffness and wave reflection in middle‐aged and older adults with T2D has not been established. The purpose of this study was to compare the effects of all‐extremity high‐intensity interval training (HIIT) vs. moderate‐intensity continuous training (MICT) on arterial stiffness and wave reflection in middle‐aged and older adults with T2D. Forty‐nine sedentary middle‐aged and older adults with T2D (46 to 78 yrs; 63 ± 1 yrs; mean ± SE), free of CVD, were randomized to HIIT (n = 18), MICT (n = 16), or non‐exercise control group (CONT; n = 15). Isocaloric HIIT and MICT were performed on a non‐weight‐bearing all‐extremity ergometer (Airdyne, Schwinn), 4 days/week for 8 weeks, under supervision. HIIT consisted of alternating intervals of 4 × 4 mins at 90% peak heart rate (HRpeak) and 3 × 3 mins at 70% HRpeak, while MICT consisted of 32 mins of continuous exercise at 70% HRpeak. Both HIIT and MICT were preceded by a 10‐min warm‐up and followed by a 5‐min cool down at 70% HRpeak. Applanation tonometry (SphygmoCor, Atcor) was used to measure at pre‐ and post‐intervention arterial stiffness (carotid‐femoral pulse wave velocity; cfPWV) and aortic wave reflection characteristics including augmentation index normalized at heart rate of 75 beats/min (AIx@75). Following the 8‐week intervention, cfPWV remained unchanged (HIIT: 10.2 ± 0.5 vs. 9.8 ± 0.4 m/s; MICT: 10.7 ± 0.7 vs. 10.3 ± 0.6 m/s; CONT: 10.3 ± 0.8 vs. 10.3 ± 0.9 m/s; pre‐ vs. post‐intervention; P = 0.5 for group × time interaction). AIx@75 decreased in response to HIIT but did not change in response to MICT and CONT (HIIT: 24.8 ± 1.6 vs. 21.8 ± 2 %, P = 0.008; MICT: 24.3 ± 2.5 vs. 23.4 ± 2.6 %, P = 0.4; CONT: 25 ± 1.8 vs. 26.9 ± 1.6 %, P = 0.1; pre‐ vs. post‐intervention; P = 0.013 for group × time interaction). In conclusion, 8 weeks of all‐extremity HIIT, but not MICT, improved wave reflection but not arterial stiffness in middle‐aged and older adults with T2D. Whether performing all‐extremity HIIT and MICT over a longer duration than 8 weeks may result in arterial destiffening in middle‐aged and older diabetic patients remains to be investigated.Support or Funding InformationThis work was supported by National Institute of Aging grant AG050203 to DDC.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.