Background – Endothelial dysfunction is a key feature of type 2 diabetes (T2D) and plays a significant role in the
early development of atherosclerosis. While lifestyle interventions incorporating weight loss and increased physical activity are advocated as the first line of treatment for T2D, the effects of weight loss, particularly when combined with exercise training on endothelial function in patients with T2D are largely unknown.
Objectives - To compare the effects of a moderate energy restricted diet, with and without aerobic exercise training on endothelial function, oxidative stress and established markers of cardiovascular risk in patients with T2D.
Design – Using a parallel randomised controlled study design, 29 sedentary, overweight and obese patients with T2D followed a 12-week moderate energy restricted diet (~5000 kJ/day, ~30% energy deficit consisting of two meal replacements and one self-prepared high protein meal) whilst either maintaining their habitual physical activity levels (DO, N=16) or undertaking a progressive aerobic exercise training program (DE, N=13).
Outcomes – Both interventions resulted in significant reductions in body weight (DO 9.5%, DE 9.0%, P<0.001 for time), body fat (14.3%), waist circumference (9.3%), blood pressure (7/4 mmHg), fasting glucose (24%), HbA1c (18%), triglycerides (38%), total cholesterol (12%, P=0.001) and malondialdehyde (28%, P<0.001), but there were no differences in the magnitude of these effects between treatments. At baseline, endothelial function assessed by brachial artery flow-mediated dilatation FMD was similar in both groups (DO 2.5 ± 5.7%, DE 4.3 ± 4.6%; P=0.26) and did not change after the interventions (P=0.76).
Conclusion – In overweight and obese patients with T2D, weight loss with and without aerobic exercise training did not improve FMD, but was effective in improving glycemic control and a range of cardiovascular risk factors. Acknowledgment – This study was supported by the Diabetes Australia Research Trust, Pharmacy Health Solutions Pty Ltd., CSIRO Human Nutrition and the ATN Centre for Metabolic Fitness.