High intensity exercise causing ischemic leg pain beneficial for PAD patients: JAMA
USA: The use of low-intensity walking exercise is significantly less effective than high-intensity home-based exercise in patients with peripheral artery disease (PAD), finds a recent study in the journal JAMA. Low-intensity walking exercise was equivalent to nonexercise control for improving 6-minute walk distance.
According to the study, in people with PAD, walking for exercise at an intensity that induces ischemic leg pain (caused by restricted blood flow) improves walking performance -- distance and length of time walking. Walking at a slow pace that does not induce ischemic leg symptoms is no more effective than no exercise at all.
These findings do not support the use of low-intensity home-based walking exercise for improving objectively measured walking performance in patients with PAD.
In people with lower-extremity peripheral artery disease, supervised high-intensity walking exercise that induces ischemic leg symptoms is the first-line therapy for people which has a poor adherence. Mary M. McDermott, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, and colleagues aimed to determine whether low-intensity home-based walking exercise at a comfortable pace significantly improves walking ability in people with PAD vs high-intensity home-based walking exercise that induces ischemic leg symptoms and vs a nonexercise control.
For the purpose, the researchers conducted multicenter randomized clinical trial at 4 US centers and including 305 participants.
People with PAD were randomized to either low-intensity walking exercise (n = 116), high-intensity walking exercise (n = 124), or nonexercise control (n = 65) for 12 months. Both exercise groups were asked to walk for exercise in an unsupervised setting 5 times per week for up to 50 minutes per session wearing an accelerometer to document exercise intensity and time. The low-intensity group walked at a pace without ischemic leg symptoms. The high-intensity group walked at a pace eliciting moderate to severe ischemic leg symptoms.
Accelerometer data were viewable to a coach who telephoned participants weekly for 12 months and helped them adhere to their prescribed exercise. The nonexercise control group received weekly educational telephone calls for 12 months.
Among 305 randomized patients, 250 (82%) completed 12-month follow-up.
Key findings of the study include:
- The 6-minute walk distance changed from 332.1 m at baseline to 327.5 m at 12-month follow-up in the low-intensity exercise group and from 338.1 m to 371.2 m in the high-intensity exercise group (within-group mean change, 34.5 m and the mean change for the between-group comparison was −40.9 m.
- The 6-minute walk distance changed from 328.1 m at baseline to 317.5 m at 12-month follow-up in the nonexercise control group, which was not significantly different from the change in the low-intensity exercise group.
- Of 184 serious adverse events, the event rate per participant was 0.64 in the low-intensity group, 0.65 in the high-intensity group, and 0.46 in the nonexercise control group.
- One serious adverse event in each exercise group was related to study participation.
"Among patients with PAD, low-intensity home-based exercise was significantly less effective than high-intensity home-based exercise and was not significantly different from the nonexercise control for improving 6-minute walk distance," wrote the authors.
"These results do not support the use of low-intensity home-based walking exercise for improving objectively measured walking performance in patients with PAD," they concluded.
The study titled, "Effect of Low-Intensity vs High-Intensity Home-Based Walking Exercise on Walk Distance in Patients With Peripheral Artery Disease: The LITE Randomized Clinical Trial," is published in the journal JAMA.