Postexercise Hemodynamics in Patients With Type 2 Diabetes: Effect of Exercise Intensity and Duration

Abstract

Background: For individuals with type 2 diabetes (T2D), the hemodynamic response to regular exercise is critical for regulating blood glucose, protecting vascular function, and reducing cardiovascular disease risk, but the hemodynamic responses to differing doses of acute exercise in T2D are unclear. We aimed to compare postexercise (PE) hemodynamics in patients with T2D in response to 4 doses of dynamic exercise.Methods: Eight subjects with well-controlled T2D (42–64 years old.; hemoglobin A1c: 6.6% ± 0.9%) participated in 4 study days, during which they exercised on a cycle ergometer at 4 different combinations of exercise duration and intensity: 30 min at 40% V˙O2peak (30@40), 30 min at 60% V˙O2peak (30@60), 60 min at 40% V˙O2peak (60@40), and 60 min at 60% V˙O2peak (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 was calculated as flow/pressure.Results: Compared with pre-exercise baseline, femoral blood flow and femoral vascular conductance were higher through at least 105 min of recovery in all conditions (all P < .05), except for the 30@40 trial. Compared with the pre-exercise measures, systolic blood pressure was lower through at least 75 min of recovery in all conditions (all P < .05), except for the 30@40 trial.Conclusion: These results suggest that exercise must be at least moderate in intensity or prolonged in duration (>30 min) to promote sustained PE elevations in skeletal muscle blood flow and reductions in systolic blood pressure in patients with T2D.