The efficacy of exercise training for cutaneous microvascular reactivity in the foot in people with diabetes and obesity : secondary analyses from a randomized controlled trial

It is unclear if cutaneous microvascular dysfunction associated with diabetes and obesity can be ameliorated with exercise. We investigated the effect of 12-weeks of exercise training on cutaneous microvascular reactivity in the foot. Thirty-three inactive adults with type 2 diabetes and obesity (55% male, 56.1 +/- 7.9 years, BMI: 35.8 +/- 5, diabetes duration: 7.9 +/- 6.3 years) were randomly allocated to 12-weeks of either (i) moderate-intensity continuous training [50-60% peak oxygen consumption (VO2peak), 30-45 min, 3 d/week], (ii) low-volume high-intensity interval training (90% VO2peak, 1-4 min, 3 d/week) or (iii) sham exercise placebo. Post-occlusive reactive hyperaemia at the hallux was determined by laser-Doppler fluxmetry. Though time to peak flux post-occlusion almost halved following moderate intensity exercise, no outcome measure reached statistical significance (p > 0.05). These secondary findings from a randomised controlled trial are the first data reporting the effect of exercise interventions on cutaneous microvascular reactivity in the foot in people with diabetes. A period of 12 weeks of moderate-intensity or low-volume high-intensity exercise may not be enough to elicit functional improvements in foot microvascular reactivity in adults with type 2 diabetes and obesity. Larger, sufficiently powered, prospective studies are necessary to determine if additional weight loss and/or higher exercise volume is required.