Upper vs. Lower Body Aerobic Training in Patients with Claudication

1. Upper vs. Lower Body Aerobic Training in Patients with Claudication Diane Treat-Jacobson, PhD, RN Assistant Professor of Nursing Center for Gerontological Nursing

2. Peripheral Arterial Diseaseand Claudication • Peripheral Arterial Disease (PAD) A disorder caused by atherosclerosis that limits blood flow to the limbs • Claudication A symptom of PAD characterized by pain, aching, or fatigue in working skeletal muscles. Claudication arises when there is insufficient blood flow to meet the metabolic demands of working skeletal muscles

3. Exercise Training for Claudication • Efficacy of treadmill training to improve walking distance in patients with claudication from is well established • Mechanisms by which exercise training improves walking distance have not been fully elucidated

4. What is the mechanism of improvement in walking distance? • Local conditioning effect – changes in muscle metabolism stimulated by exercising specific muscles affected by limited blood flow • Systemic effect – changes in central cardiovascular conditioning and/or vascular function, leading to improved walking ability

5. Exercise Training for Claudication • There is limited information about the potential of aerobic arm training to improve onset to claudication (OCD) distance and maximal walking distance (MWD) • One study demonstrated equivalent benefit of upper and lower extremity cycle ergometry exercise on walking distance (Walker et. al, 2000) • No previous studies have compared aerobic arm training to treadmill training in patients with claudication

6. Peripheral arterial disease Reduced oxygen delivery Ischemia- Reperfusion Endothelial Dysfunction : Systemic inflammation Muscle fiber denervation Muscle fiber atrophy Effects of exercise training on pathophysiological correlates of Deconditioning and worsening: Obesity Hypertension Hyperlipidemia Hyperglycemia Thrombotic risk claudication Good evidence for improvement Potential improvement Altered muscle metabolism Short-term: may worsen Long-term: may improve Impaired walking ability Decreased quality of life Poor aerobic capacity Reduced muscle strength & endurance Potential Mechanisms by Which Exercise Improves Claudication Stewart et al. Medical Progress: Exercise Training for Claudication. NEJM 2002; 347(24):1941-1951

7. Exercise Training for Claudication Study* Specific Aims: • Determine the relative efficacy of supervised treadmill training or arm ergometry alone, or in combination, versus ‘usual care’ in subjects with PAD • Evaluate the extent to which the effects are maintained or improved following completion of supervised program *Funded by a American Heart Association Scientist Development Grant

8. Methods • Randomized controlled pretest-posttest design • 4 groups • Treadmill training • Upper extremity ergometry • Combined training • Control Group

9. Inclusion Age > 18 years Resting ABI < 0.90 or 20% drop in post-exercise ABI Lifestyle limitation due to claudication Ability to complete study procedures Exclusion Uncontrolled hypertension or diabetes Recent peripheral or coronary revascularization procedure Fontaine stage 3 (rest pain) or 4 (tissue loss) Unstable heart disease Walking limited by factors than claudication Entry Criteria

10. Procedures • Screening Visit • Informed consent • Medical History & Physical Exam, including ankle brachial index (ABI) • Quality of life and health status questionnaires • Symptom-limited graded cardiopulmonary treadmill exercise test (x2) • Post-Exercise ABI • Baseline arm ergometry test

11. Exercise Groups • Supervised in the exercise laboratory 3 times/week for 12 weeks • Sessions 70 minutes in length, 5 minutes warm-up, 60 minutes of exercise, 5 minutes cool down • Recording of daily exercise outside supervised setting

12. Treadmill Exercise Program • Treadmill walking • Speed: 2.0 mph • Grade increased by 0.5% every 8 minutes until onset of moderate claudication (rating: 4 out of 5) • After 7% grade is reached, increase speed at 0.1 MPH intervals • Time: 60 minutes including rest periods

13. Upper Body Exercise Program • Arm Ergometry • Watts start at one level below maximal test • 2 minutes exercise, 2 minutes rest • Gradually increase watts, exercise-rest intervals throughout program as tolerated • Time: 60 minutes including rest periods

14. Combination Exercise Program • 20 minutes Arm Ergometry • 40 minutes Treadmill • Increase intensity as with other protocols • Time: 60 minutes including rest periods

15. Control Group • Instructed to continue ‘usual care’ • Provided specific written walking instructions • Instructed on completion of daily exercise records • Weekly follow-up in the laboratory, review of exercise records

16. Post-Training Assessment • Re-assessment of all outcome variables within 1 week of completion of training program, or 12 weeks after enrollment for control group • Follow-up 12 weeks following completion of program (approx. 24 weeks)

17. Outcome Measures • Walking Distance (pain free, OCD and maximal, MWD) • Cardiovascular Variables • Quality of Life, Functional Status and Mood

18. Demographic and Medical Variables

19. Median Onset of Claudication Distance (OCD) and Maximal Walking Distance (MWD) Scores at Baseline and Following 12 Weeks of Exercise Training

20. Treadmill (n=8). Upper Body Ergometer (n=6) Combination (n=10) Combination (n=10) Median Change in Onset of Claudication Distance 300 200 Meters 100 0 Baseline 12Weeks Test Treadmill z= 2.37, p<0.018 Upper Body Ergometer z= 2.20, p<0.028 Combination z= 1.96, p=0.05

21. Treadmill z=2.67, p=0.008 Treadmill z=2.67, p=0.008 Upper Body Ergometer z=2.20, p=0.028 Upper Body Ergometer z=2.20, p=0.028 Combination z=2.80, p=0.005 Combination z=2.80, p=0.005 Median Change in Maximal Walking Distance 700 700 600 600 500 500 Meters 400 400 Treadmill (n=9) Treadmill (n=9) Treadmill (n=9) 300 300 Upper Body Upper Body Upper Body Ergometer (n=6) 200 200 100 100 Combination (n=10) Combination (n=10) Combination (n=10) 0 0 Baseline Baseline 12 Weeks 12 Weeks Test

22. Conclusions • Preliminary data suggest that arm ergometry and treadmill training offer similar benefits in improving OCD and MWD. • Mechanisms of improvement with both forms of exercise require further study. • For those with severe PAD who cannot perform walking exercise, arm exercise is a promising alternative.

23. Future Research • Preliminary data indicate that there is improvement in those performing upper body aerobic exercise training • This finding suggests a systemic mechanism of exercise-related improvement • Assessment of physiological variables associated with endothelial injury, thrombosis/hemostasis, and inflammation in those engaging in ischemic versus non-ischemic exercise is warranted

24. A Model of the Impact of Exercise on Patients with Claudication

25. Clinical Scholar Mentorship Team Jean Wyman, PhD, RN, FAAN Nigel Key, MD Arthur S. Leon, MD Don Dengel, PhD Jayne Fulkerson, PhD Research Team Ulf Bronas, MS Arthur S. Leon, MD Lora Sweezy Kristie Koch Kimberly Miller Kathryn Koch Judith Regensteiner, Consultant Acknowledgements