Exercise therapy to improve mobility, active behaviour and quality of life of chronic kidney disease patients with peripheral artery disease: study protocol for the EXACT-CKDPAD multicentre randomised controlled trial.

The combination of chronic kidney disease (CKD) and peripheral artery disease (PAD) enhances the already present high cardiovascular risk, exposing the affected patients to unfavourable long-term clinical outcomes. Physical exercise is considered an effective treatment for reducing sedentary behaviour and improving quality of life, but several barriers limit patient participation. In this parallel-design, single-blinded, randomised controlled trial, we will enrol 130 patients with concomitant CKD at stages III and IV and PAD at the claudication stage to be randomised into a 6-month exercise (Ex) or control (Co) intervention. The Ex programme will consist of two daily 10 min interval walking sessions (1 min of walking followed by 1 min of resting), with gait speed controlled via a metronome and increased approximately weekly. The Co group will receive standard nephrological care. Outcomes will be assessed before and after treatment, as well as at the 12-month follow-up. The primary outcome will be the 6 min walking distance. The secondary outcomes will include quality of life, lower limb and handgrip strength, body composition and bone mineral density, as well as circulating indexes of kidney function and long-term clinical outcomes. Since no trials have been published that purposely enrol this high-risk population (CKD-PAD), the eventual positive results will validate a simple, pain-free exercise intervention that can be carried out at home to improve patients' mobility and quality of life. Trial registration number: NCT06621264.