Whole-body vibration training on functional capacity, vascular function, and glycemic control in individuals with type 2 diabetes and peripheral arterial disease: protocol for a randomized controlled trial.

Walking-based exercise improves symptoms in type 2 diabetes and peripheral arterial disease, but adherence is limited by low fitness and leg pain.

• The paper identifies walking-based exercise as a standard intervention for this population.
• Barriers to adherence include low fitness levels and leg pain associated with peripheral arterial disease.
• This limitation motivated investigation of an alternative exercise modality.

Whole-body vibration stimulates muscle contractions and increases limb and microvascular blood flow, potentially mimicking the impact of walking.

• Prior studies suggest whole-body vibration improves endothelial function and reduces arterial stiffness.
• Prior studies also suggest lower glycated hemoglobin following vibration therapy.
• Effects of whole-body vibration on functional capacity in individuals with type 2 diabetes and peripheral arterial disease remain unclear prior to this trial.

The trial is designed as a randomized controlled trial with 48 participants (24 per group) with a non-inferiority design.

• Participants must be aged 50 years or older.
• Inclusion requires ankle-brachial index of 0.9 or less or toe-brachial index of 0.7 or less.
• Participants must have Fontaine stage I to IIb peripheral arterial disease.
• A pre-specified non-inferiority margin is used for the primary outcome (incremental shuttle walk test distance).

The intervention protocol involves whole-body vibration or supervised treadmill walking delivered over 12 weeks at three sessions per week.

• Whole-body vibration will be delivered using a Galileo plate.
• The comparator is supervised treadmill walking.
• Both groups undergo the same frequency and duration of the intervention period.
• Adverse events will be monitored throughout the trial.

The primary outcome is distance achieved on the incremental shuttle walk test, with multiple secondary outcomes covering vascular function, glycemic control, and quality of life.

• Secondary outcomes include ankle-brachial index and toe-brachial index.
• Vascular secondary outcomes also include brachial artery flow mediated dilation.
• Glycated hemoglobin is included as a secondary outcome for glycemic control.
• Quality of life is assessed via SF-36 health related-quality of life and Peripheral Artery Questionnaire scores.

Statistical analyses will follow the intention-to-treat principle using a general linear model with pre-specified covariates.

• The general linear model will be adjusted for age, sex, peripheral arterial disease category, diabetes duration, and baseline incremental shuttle walk test distance.
• The intention-to-treat principle is explicitly stated as the analytical framework.
• The trial is registered in the Thai Clinical Trials Registry as TCTR20251020003.