The effect of exercise training on ankle-brachial index in type 2 diabetes

•We studied the effect of exercise on ankle-brachial index (ABI) in type 2 diabetes.•ABI increased in exercisers vs. controls over 6 months.•An increase in ankle blood pressure explained the observed change in ABI.•The increase in ABI was stronger in patients with lower baseline values (ABI<1.0).•The change in ABI was independent of changes in blood pressure or glycemia.

IntroductionThough being physically active has associated with a healthier ankle-brachial index (ABI) in observational studies, ABI usually does not change with exercise training in patients with peripheral artery disease (PAD). Less is known about the effect of exercise training on ABI in patients without PAD but at high risk due to the presence of type 2 diabetes (T2DM).MethodsParticipants (n = 140) with uncomplicated T2DM, and without known cardiovascular disease or PAD, aged 40–65 years, were randomized to supervised aerobic and resistance training 3 times per week for 6 months or to a usual care control group. ABI was measured before and after the intervention.ResultsBaseline ABI was 1.02 ± 0.02 in exercisers and 1.03 ± 0.01 in controls (p = 0.57). At 6 months, exercisers vs. controls improved ABI by 0.04 ± 0.02 vs. −0.03 ± 0.02 (p = 0.001). This change was driven by an increase in ankle pressures (p < 0.01) with no change in brachial pressures (p = 0.747). In subgroup analysis, ABI increased in exercisers vs. controls among those with baseline ABI <1.0 (0.14 ± 0.03 vs. 0.02 ± 0.02, p = 0.004), but not in those with a baseline ABI ≥1.0 (p = 0.085). The prevalence of ABI between 1.0 and 1.3 increased from 63% to 78% in exercisers and decreased from 62% to 53% in controls. Increased ABI correlated with decreased HbA1c, systolic and diastolic blood pressure, but the effect of exercise on ABI change remained significant after adjustment for these changes (β = 0.061, p = 0.004).ConclusionThese data suggest a possible role for exercise training in the prevention or delay of PAD in T2DM, particularly among those starting with an ABI <1.0.Clinicaltrials.gov Registry Number: NCT00212303.