Differential effects of sex on adaptive responses of skeletal muscle vasodilation to exercise training in type 2 diabetes

Aims: We tested the hypotheses that exercise training improves the peak and dynamic responses of leg vascular conductance (LVC) in males and females with type 2 diabetes (T2DM). Methods: Forty-one males and females with T2DM were assigned to two training groups and two control groups. Twelve weeks of aerobic/resistance training was performed three times per week, 60-90 min per session. Responses of calf muscle blood flow and systemic arterial pressure during incremental and constant-load (30% maximal voluntary contraction) intermittent plantar-flexion protocols in the supine position were recorded. Results: Training significantly increased peak LVC in males (4.86 +/- 1.88 to 6.06 +/- 2.06 ml.min(-1).mm Hg-1) and females (3.91 +/- 1.13 to 5.40 +/- 1.38 ml.min(-1).mm Hg-1) with no changes in control groups. For dynamic responses, training significantly increased the amplitude of the fast growth phase of LVC (1.81 +/- 1.12 to 2.68 +/- 1.01 ml.min(-1).mm Hg-1) and decreased the time constant of the slow growth phase (43.6 +/- 46.4 s to 16.1 14.0 s) in females, but no improvements were observed in control females or in any of the two male groups. Conclusions: These data suggest that training increases the peak vasodilatory response in males and females, whereas the speed of the dynamic response of vasodilation is improved in females but not males.

Automated summary

Exercise training was found to improve leg vascular conductance in males and females with type 2 diabetes, increasing peak vasodilatory response. Additionally, dynamic response of vasodilation was improved in females but not in males after training.