ABSTRACT
BACKGROUND: This study assessed the relationship between lower limb hemodynamics and metabolic parameters with walking tolerance in patients with intermittent claudication (IC). PATIENTS AND METHODS: Resting ankle-brachial index (ABI), baseline blood flow (BF), BF response to reactive hyperemia (BFRH), oxygen uptake (VO2), initial claudication distance (ICD) and total walking distance (TWD) were measured in 28 IC patients. Pearson and Spearman correlations were calculated. RESULTS: ABI, baseline BF and BF response to RH did not correlate with ICD or TWD. VO2 at first ventilatory threshold and VO2peak were significantly and positively correlated with ICD (r = 0.41 and 0.54, respectively) and TWD (r = 0.65 and 0.71, respectively). CONCLUSIONS: VO2peak and VO2 at first ventilatory threshold, but not ABI, baseline BF and BFHR were associated with walking tolerance in IC patients. These results suggest that VO2 at first ventilatory threshold may be useful to evaluate walking tolerance and improvements in IC patients.
Subject(s)
Exercise Test , Exercise Tolerance , Intermittent Claudication/diagnosis , Muscle, Skeletal/blood supply , Muscle, Skeletal/metabolism , Oxygen Consumption , Pulmonary Ventilation , Walking , Aged , Anaerobic Threshold , Ankle Brachial Index , Brazil , Hemodynamics , Humans , Hyperemia/physiopathology , Intermittent Claudication/metabolism , Intermittent Claudication/physiopathology , Lower Extremity , Male , Middle Aged , Muscle, Skeletal/physiopathology , Predictive Value of Tests , Regional Blood FlowABSTRACT
BACKGROUND: Exercise training is recommended as the first-line therapy for intermittent claudication patients. However, the effects of exercise therapy on cardiovascular function of these patients have been poorly studied. The aim of this study is to compare the effects of walking and strength training on cardiovascular responses assessed at rest and during exercise in patients with intermittent claudication. PATIENTS AND METHODS: Thirty-four patients with stable symptoms of intermittent claudication were randomized into two groups: strength training (ST) consisting of eight exercises, three sets of 10 repetitions, intensity of 11 - 13 on 15-grade Borg scale, 2-min interval between sets; and walking training (WT) consisting of walking on a treadmill, 15 bouts of 2-min, intensity of 11 - 13 on 15-grade Borg scale, with a 2-min interval between bouts. Before and after 12 weeks, blood pressure, heart rate and rate pressure product were measured at rest and during a progressive treadmill test until maximal claudication pain. RESULTS: Fifteen patients in each group completed the training program. After the training programs, resting systolic blood pressure (ST:-6 ± 13 mmHg and WT:-3 ± 18 mmHg, P = .04), heart rate (ST: -6 ± 10 bpm and WT:-2 ± 9 bpm, P = .03), and rate pressure product (ST:-1485 ± 1442 mmHg*bpm and WT:- 605 ± 2145 mmHg*bpm, P = .01) decreased significantly and similarly in both groups. Submaximal systolic blood pressure (ST: -14 ± 23 mmHg and WT:-6 ± 23 mmHg, P = .02), and rate pressure product (ST:-1579 ± 3444 mmHg*bpm and WT: -1264 ± 3005 mmHg*bpm, P = .04) decreased significantly and similarly in both groups. There were no changes in submaximal heart rate after ST and WT. Maximal systolic blood pressure, heart rate, and rate pressure product did not change in either group, although maximal exercise time increased similarly in the ST and WT groups (+31 ± 19 %, and +31 ± 32 %, respectively, P < .01). CONCLUSIONS: Strength and walking trainings promoted similar increases in walking capacity and decreases in resting and submaximal exercise cardiovascular load.
