Peripheral Arterial Disease, Hypertension, Diabetes
Conditions
Keywords
peripheral arterial disease, exercise, resistance training, cardiac rehabilitation
Brief summary
Background: Muscle atrophy and reduced leg strength are related to exercise intolerance in patients with intermittent claudication (IC), suggesting that strength training (ST) could improve exercise performance in these patients. Objective: Analyze the effects of ST in walking capacity in patients with IC comparing with walking training (WT) effects. Intervention: Patients were randomized into ST and WT. Both groups trained twice a week, for 12 weeks, at the same rate of perceived exertion. ST consisted of 3 sets of 10 repetitions of whole body exercises. WT consisted of 15 two-minute bouts of walking intercalated with 2 minutes of resting. Measurements: Walking capacity, peak VO2, walking economy, ankle brachial index, ischemic window and knee extension strength
Detailed description
From July 2005 to December 2006, three hundred patients with peripheral arterial disease, who were enrolled in a tertiary center specialized in vascular disease and were able to walk for at least 2 minutes at 2 miles per hour, were invited to a meeting at which explanations about this study were given. 80 patients attended the meeting, 60 of them decided to take part of the study, and 52 attended for the screening tests. Patients were included in the study if they met the following criteria: Fontaine stage II peripheral arterial disease, symptoms of IC for at least 6 months, ankle/brachial index (ABI) at rest ≤ 0.90 in 1 or 2 legs, reduction of ABI after treadmill test, and exercise tolerance limited by IC. Patients were excluded under the following conditions: presence of chronic lung disease, inability to obtain ABI measurement due to noncompressible vessels, exercise tolerance limited by factors other than claudication (eg, dyspnea or orthopedic problems), poorly controlled blood pressure, presence of electrocardiogram response suggestive of myocardial ischemia during the exercise test, and history of revascularization in the previous year. Procedures Patients were randomly (by drawing lots) divided into 2 groups: strength (ST, n = 17) and walking (WT, n = 17) training. They were evaluated at baseline (pre-training) and after 12 weeks of exercise training (post-training). During evaluations were assessed exercise tolerance and strength. Both training programs (ST and WT) were supervised, conducted twice a week, lasted for 12 weeks, and started after a 2-week preconditioning-orientation phase. In both programs, rate of perceived exertion during exercise was kept similar and between 11 to 13 on the15-grade Borg scale. Furthermore, the duration of exercise sessions was prescribed as 30 min of exercise for ST and WT groups.
Interventions
BEHAVIORALWalking Training
The Walking Training program was performed using a treadmill. In each session, patients performed fifteen 2-min bouts of exercise followed by a 2-min rest interval, as previously described. Walking speed was set in order to induce perceived exertion of 11 to 13 and claudication pain in the last 30 seconds of each exercise bout.
BEHAVIORALStrength Training
The strength training program consisted of 8 exercises (leg press, crunches, unilateral knee extension, seated row, unilateral knee flexion, seated bench press, calf raises on leg press, and seated back extension). In each exercise, subjects performed 3 sets of 10 repetitions with a 2-min interval between sets and exercises.
Sponsors
Fundação de Amparo à Pesquisa do Estado de São Paulo
University of Sao Paulo
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to 85 Years
Healthy volunteers
No
Inclusion criteria
* Fontaine stage II peripheral arterial disease(14) * Symptoms of intermittent claudication for at least 6 months * Ankle/brachial index (ABI) at rest ≤ 0.90 in 1 or 2 legs * Reduction of ABI after treadmill test * Exercise tolerance limited by intermittent claudication
Exclusion criteria
* Presence of chronic lung disease * Inability to obtain ABI measurement due to noncompressible vessels * Exercise tolerance limited by factors other than claudication (e.g., dyspnea or orthopedic problems) * Poorly controlled blood pressure * Presence of electrocardiogram response suggestive of myocardial ischemia during the exercise test * History of revascularization in the previous year
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total Walking Distance | 12 weeks | The maximal walking distance |
Countries
Brazil
Participant flow
Recruitment details
From July 2005 to December 2006, three hundred patients with peripheral arterial disease, who were enrolled in a tertiary center specialized in vascular disease and were able to walk for at least 2 minutes (min) at 2 miles per hour (mph), were invited to a meeting at which explanations about this study were given.
Pre-assignment details
Seven patients did not present symptoms of claudication during the treadmill test, 5 presented electrocardiogram response suggestive of myocardial ischemia, 4 presented exercise tolerance limited by other factors than claudication, and 2 presented poorly controlled blood pressure. All these patients were not included in the study.
Participants by arm
| Arm | Count |
|---|---|
| Strength Training Patients who performed strength training. Strength training program consisted of 8 exercises (leg press, crunches, unilateral knee extension, seated row, unilateral knee flexion, seated bench press, calf raises on leg press, and seated back extension). In each exercise, subjects performed 3 sets of 10 repetitions with a 2-minutes interval between sets and exercises. | 17 |
| Walking Training Patients who performed walking training. Walking training program was performed using a treadmill. In each session, patients performed fifteen 2-minutes bouts of exercise followed by a 2-minutes rest interval, as previously described. Walking speed was set in order to induce perceived exertion of 11 to 13 and claudication pain in the last 30 s of each exercise bout. | 17 |
| Total | 34 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Physician Decision | 2 | 2 |
Baseline characteristics
| Characteristic | Strength Training | Walking Training | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 13 Participants | 14 Participants | 27 Participants |
| Age, Categorical Between 18 and 65 years | 4 Participants | 3 Participants | 7 Participants |
| Age, Continuous | 65.7 years STANDARD_DEVIATION 9.5 | 64.6 years STANDARD_DEVIATION 8.8 | 65.1 years STANDARD_DEVIATION 9.3 |
| Gender Female | 5 Participants | 7 Participants | 12 Participants |
| Gender Male | 12 Participants | 10 Participants | 22 Participants |
| Region of Enrollment Brazil | 17 participants | 17 participants | 34 participants |
| Total walking distance | 618 meter STANDARD_DEVIATION 282 | 572 meter STANDARD_DEVIATION 231 | 595 meter STANDARD_DEVIATION 244 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 2 / 17 | 2 / 17 |
| serious Total, serious adverse events | 0 / 17 | 0 / 17 |
Outcome results
Primary
Total Walking Distance
The maximal walking distance
Time frame: 12 weeks
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Strength Training | Total Walking Distance | 618 meter | Standard Deviation 282 |
| Walking Training | Total Walking Distance | 572 meter | Standard Deviation 231 |
Comparison: The effect of training in both groups were assessed by a 2-way ANOVA (Time x Group) for repeated measures. When significance was obtained, the Newman-Keuls post hoc test was used to identify the differences.p-value: <0.05ANOVA