Benefit of exercise conditioning for patients with peripheral arterial disease.

Abstract

Patients with atherosclerotic peripheral arterial disease (PAD) of the lower extremities have impaired walking ability due to exercise-induced muscle ischemia and the resultant pain of intermittent claudication. To evaluate the benefit of exercise training as a treatment for patients with PAD, as well as possible mechanisms associated with improvement, we randomly assigned 19 men with disabling claudication to treated and control groups. Treatment consisted of supervised treadmill walking (1 hr/day, 3 days/wk, for 12 weeks) with progressive increases in speed and grade as tolerated. Graded treadmill testing was performed to maximal toleration of claudication pain on entry and after 12 weeks of training to define changes in peak exercise performance. After 12 weeks, treated subjects had increased their peak walking time 123%, peak oxygen consumption 30%, and pain-free walking time 165% (all p<0.05). Control subjects had no change in peak oxygen consumption, but after 12 weeks, peak walking time increased 20% (p<0.05). In treated subjects, maximal calf blood flow (measured by a plethysmograph) increased 38+45% (p<0.05), but the change in flow was not correlated to the increase in peak walking time. Elevated plasma concentrations of acylcarnitines have been associated with the functional impairment of PAD and may reflect the metabolic state of ischemic skeletal muscle. In treated subjects, a 26% decrease in resting plasma short-chain acylcarnitine concentration was correlated with improvement in peak walking time (r= -0.78, p <0.05). Thus, 12 weeks of exercise training for patients with PAD improved peak exercise performance and claudication pain severity, which in part may be due to an improvement in skeletal muscle oxidative metabolism. (Circulation 1990;81:602-609) A therosclerotic peripheral arterial disease (PAD) of the lower extremities, when associated with intermittent claudication, results in a moderate-to-severe impairment in walking ability. Patients with PAD are unable to walk more than a short distance on level ground and have a severely limited peak exercise capacity during graded treadmill exercisel-4 in a range that allows for only very light to light activities.5 As a result, the energy requirements of many leisure-and work-related tasks exceed the peak exercise capacity of these patients.Exercise training has been shown to improve walking ability on level ground6-8 and during constant-

Oral Beraprost Sodium, a Prostaglandin I 2 Analogue, for Intermittent Claudication

“…This is a common feature of most of the trials that used treadmill exercise tests to assess intermittent claudication and can be explained by the effects of exercise itself or habituation to the treadmill test. 13,14 A regression-to-the-mean phenomenon cannot be excluded either, although it should have been partly avoided by excluding from randomization patients with great changes in pain-free walking distance during the run-in part of the study. 15 The mean differences between the BPS and placebo groups for the increases in pain-free (36 m) and in absolute (70 m) walking distances were in the range of what was observed in clinical trials of pentoxifylline and cilostazol.…”

The transcriptional coactivator PGC-1α mediates exercise-induced angiogenesis in skeletal muscle

“…Exercise remains one of the most efficient interventions for most of these. Peripheral artery disease (PAD), in particular, is a leading cause of morbidity and the most common cause of limb amputation in the U.S., and yet even the best medical therapy available is less efficacious than simply walking daily (1,2). Muscle adapts to endurance-type exercise by triggering mitochondrial biogenesis, changes in fiber composition, and the growth of new blood vessels, or angiogenesis (3)(4)(5).…”

The effects of exercise training in patients with peripheral vascular disease - a review

“…Since this study a number of randomised controlled trials (Table I) have shown similar results. 8,19,22,23,25,29,30,35,36,41,44 It is clear from Table I that exercise training improves walking tolerance in patients with PVD. Indeed when comparing the effects of exercise training with PTA, exercise training was more beneficial after a 6-month period.…”

“…Studies showed that training on a treadmill produced substantial increases in walking distances. 22,23,35,39 Treadmill walking was established as the accepted mode of exercise training and few studies explored the effects of alternative modes of training on walking distances in patients with PVD.…”

“…This is helpful for practitioners as exercise programmes of 3 or 6 months can be daunting Two parameters are usually measured on a treadmill: pain-free walking distance (PFWD) and maximum walking distance (MWD). 8,22,23 Use of the treadmill as a tool to measure walking distance has been criticised because the tests are not always reproducible. 26,34,37 There is disagreement about whether a graded test (a test when the speed or gradient increases at set time intervals) is more or less reproducible than a constant load test (one that does not increase in speed or gradient).…”