Systemic and lower limb hemodynamics following dynamic exercise in type 2 diabetics: effects of exercise intensity and duration (705.12)

Abstract

For individuals with type 2 diabetes mellitus (T2DM), regular exercise is critical for protecting vascular function and reducing cardiovascular disease risk, but the hemodynamic responses to differing doses of acute exercise in type 2 diabetics (T2D) are unclear. Our aim was to compare postexercise (PE) hemodynamics in T2D in response to four different doses of acute dynamic exercise. Two subjects with well‐controlled T2DM (42‐48 yrs; Hemoglobin A1c: 6.6 ± 0.7%) participated in four study days, during which they exercised on an upright cycle ergometer at four different combinations of exercise duration and intensity: 30 min at 40% VO2 peak (30@40), 30 min at 60% VO2 peak (30@60), 60 min at 40% VO2 peak (60@40), and 60 min at 60% VO2 peak (60@60). Heart rate, arterial pressure, and femoral blood flow (Doppler ultrasound) were measured pre‐exercise and every 15 min through 120 min PE. Femoral vascular conductance (FVC) was calculated as flow/pressure. Compared to pre‐exercise baseline, FVC was higher and mean arterial pressure (MAP) was lower throughout 120 min of recovery in all conditions, except for the 30@40 trial. Expressed as percentage change from pre‐exercise baseline, at 30 min PE, FVC was elevated 7.8 ± 1.3% on the 30@40 day, 32.3 ± 1.9% on the 30@60 day, 40.7 ± 4.6% on the 60@40 day, and 43.9 ± 9.0% on the 60@60 day. Compared to pre‐exercise baseline, at 30 min PE, MAP was reduced 0.53 ± 0.6% on the 30@40 day, 2.1 ± 2.9% on the 30@60 day, 4.2 ± 0.2% on the 60@40 day, and 6.1 ± 0.6% on the 60@60 day. These preliminary results suggest a somewhat dose‐dependent elevation of PE skeletal muscle blood flow and reduction in PE MAP in T2D.Grant Funding Source: Supported by the Salisbury University Faculty Mini‐Grant