Gabriel Grizzo Cucato

Strength training increases walking tolerance in intermittent claudication patients: Randomized trial

OBJECTIVE To analyze the effects of strength training (ST) in walking capacity in patients with intermittent claudication (IC) compared with walking training (WT) effects. METHODS Thirty patients with IC 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 three sets of 10 repetitions of whole body exercises. WT consisted of 15 bouts of 2-minute walking. Before and after the training program walking capacity, peak VO(2), VO(2) at the first stage of treadmill test, ankle brachial index, ischemic window, and knee extension strength were measured. RESULTS ST improved initial claudication distance (358 +/- 224 vs 504 +/- 276 meters; P < .01), total walking distance (618 +/- 282 to 775 +/- 334 meters; P < .01), VO(2) at the first stage of treadmill test (9.7 +/- 2.6 vs 8.1 +/- 1.7 mL.kg(-1).minute; P < .01), ischemic window (0.81 +/- 1.16 vs 0.43 +/- 0.47 mm Hg minute meters(-1); P = .04), and knee extension strength (19 +/- 9 vs 21 +/- 8 kg and 21 +/- 9 vs 23 +/- 9; P < .01). Strength increases correlated with the increase in initial claudication distance (r = 0.64; P = .01) and with the decrease in VO(2) measured at the first stage of the treadmill test (r = -0.52; P = .04 and r = -0.55; P = .03). Adaptations following ST were similar to the ones observed after WT; however, patients reported lower pain during ST than WT (P < .01). CONCLUSION ST improves functional limitation similarly to WT but it produces lower pain, suggesting that this type of exercise could be useful and should be considered in patients with IC.

Translation and validation of the walking impairment questionnaire in Brazilian subjects with intermittent claudication

BACKGROUND The Walking Impairment Questionnaire (WIQ) has been used to evaluate walking impairment in subjects with intermittent claudication (IC). However, this questionnaire has yet to be translated to Brazilian Portuguese, which limits its use in Brazilian subjects. OBJECTIVE To translate and analyze the validity and reliability of WIQ in Brazilian subjects with IC. METHODS Forty-two patients with IC, determined by the ankle-brachial index < 0.90, participated in the study. After translation and re-translation, carried out by two independent translators, the construct validity of the WIQ was analyzed by correlating the WIQ scores with the Medical Outcome Study Questionnaire Short Form 36 (SF-36) scores and the physical fitness performance (treadmill and strength tests). The reliability was analyzed with a 7-day interval between two questionnaire applications. RESULTS Significant correlations between the WIQ domains and the SF-36 (functional capacity, physical aspects, bodily pain and emotional aspects) and physical fitness performance (treadmill and strength tests) were observed. Moreover, the intraclass coefficient correlation ranged from 0.72 to 0.81, and there were no differences in WIQ scores between the two questionnaire applications. CONCLUSION The Brazilian Portuguese version of the WIQ is valid and reliable to be used in Brazilian subjects with IC.FUNDAMENTO: El Walking Impairment Questionnaire (WIQ) se utiliza para la obtencion de informaciones sobre la percepcion de locomocion de los individuos con claudicacion intermitente (CI). No obstante, este cuestionario aun no ha sido traducido al portugues, lo que limita su utilizacion en muestra brasilena. OBJETIVO: Traducir y verificar la validez y reproducibilidad del WIQ en brasilenos con CI. METODOS: Participaron en este estudio 42 individuos con CI, diagnosticados por el indice tobillo-brazo < 0,90. Luego de los procedimientos de traduccion y retraduccion del cuestionario, realizado por dos traductores independientes, la validez del constructo del WIQ se analizo al correlacionar los scores del WIQ con los scores del Medical Outcome Study Questionnaire Short Form 36 (SF-36) y con el desempeno de pruebas de aptitud fisica (marcha y de fuerza maxima). La reproducibilidad se analizo en dos aplicaciones del WIQ con 7 dias de intervalo. RESULTADOS: Se encontro correlacion significativa entre los dominios del WIQ, los dominios del SF-36 (capacidad funcional, aspectos fisicos, dolor y aspectos emocionales) y el desempeno en las pruebas de aptitud fisica (marcha y fuerza maxima). Ademas de ello, se verificaron coeficientes de correlacion intraclase que variaron de 0,72 a 0,81, y no hubo diferencia entre los scores del WIQ entre las dos aplicaciones del cuestionario. CONCLUSION: La version en portugues del WIQ es valida y reproducible en brasilenos con CI.

Post-resistance exercise hypotension in patients with intermittent claudication

OBJECTIVE: To verify the acute effects of resistance exercise on post‐exercise blood pressure in patients with intermittent claudication. METHODS: Eight patients randomly underwent two experimental sessions: a session of resistance exercise (R: 6 exercises, 3 sets of 12, 10 and 8 reps with a perceived exertion of 11 to 13 on the 15‐grade Borg scale) and a control session (C: resting on exercise machines). RESULTS: Before and for 60 min following an intervention, auscultatory blood pressure was measured while subjects rested in a sitting position. After the C session, systolic, diastolic and mean blood pressures did not change from the pre‐intervention values, while these values decreased significantly after the R session throughout the entire recovery period (greatest decreases  =  ‐14±5, ‐6±5, and ‐9±4 mmHg, respectively, P < 0.05). CONCLUSION: After a single bout of resistance exercise patients with intermittent claudication exhibited reduced systolic, diastolic and mean blood pressures, suggesting that acute resistance exercise may decrease cardiovascular load in these patients.

Obesity decreases time to claudication and delays post-exercise hemodynamic recovery in elderly peripheral arterial disease patients.

Background: Althoughobesity is usually observed in peripheral arterial disease (PAD) patients, the effects of the association between these diseases on walking capacity are not well documented. Objective: The main objectives of this study were to determine the effects of obesity on exercise tolerance and post-exercise hemodynamic recovery in elderly PAD patients. Methods: 46 patients with stable symptoms of intermittent claudication were classified according to their body mass index (BMI) into normal group (NOR) = BMI <28.0 and obese or in risk of obesity group (OBE) = BMI ≥28.0. All patients performed a progressive graded treadmill test. During exercise, ventilatory responses were evaluated and pre- and post-exercise ankle and arm blood pressures were measured. Results: Exercise tolerance and oxygen consumption at total walking time were similar between OBE and NOR. However, OBE showed a lower claudication time (309 ± 151 vs. 459 ± 272 s, p = 0.02) with a similar oxygen consumption at this time. In addition, OBE presented a longer time for ankle brachial index recovery after exercise (7.8 ± 2.8 vs. 6.3 ± 2.6 min, p = 0.02). Conclusion: Obesity in elderly PAD patients decreased time to claudication, and delayed post-exercise hemodynamic recovery. These results suggest that muscle metabolic demand, and not total workload, is responsible for the start of the claudication and maximal exercise tolerance in PAD patients. Moreover, claudication duration might be responsible for the time needed to a complete hemodynamic recovery after exercise.

Impact of a supervised strength training or walking training over a subsequent unsupervised therapy period on walking capacity in patients with claudication

Previous studies have demonstrated that supervised strength training (ST) or walking training (WT) improve walking capacity in patients with claudication. However, it remains unknown whether these improvements would be sustained over a subsequent unsupervised period. This article reports the findings of a study to analyze whether the improvements in walking capacity, achieved with a supervised ST or WT, would be sustained over a subsequent unsupervised therapy period in patients with claudication. Patients were initially randomized to supervised exercise consisting of ST (n = 15) or WT (n = 15) for 12 weeks. After this period, 12 patients in each group consented to be followed for an additional 12 weeks of unsupervised therapy. Initial claudication distance (ICD) and total walking distance (TWD) were measured at baseline, after the supervised period (Week 12) and after the unsupervised period (Week 24). In comparison with baseline values, both groups similarly increased ICD and TWD at Week 12. From Week 12 to Week 24, both groups similarly decreased ICD (ST: -55 ± 110 m and WT: -82 ± 142 m, P =.04) and TWD (ST: -68 ± 186 m and WT: -128 ± 112 m, P < .01). However, in both groups, ICD (ST: +126 ± 149 m and WT: +50 ± 167 m, P = .01) and TWD (ST: +104 ± 162 m and WT: +45 ± 139 m, P =.01) at Week 24 remained greater than baseline values. The conclusion is that supervised ST or WT followed by an unsupervised therapy period similarly decreased walking capacity in patients with claudication. However, after the unsupervised period, walking capacity remained at a higher level than before the onset of the supervised exercise-training period.

Post-walking Exercise Hypotension in Patients with Intermittent Claudication

PURPOSE This study aimed to investigate the acute effect of intermittent walking exercise (WE) on blood pressure (BP) responses in patients with intermittent claudication (IC). Secondly, this study aimed to gain improved insight into the physiological mechanisms controlling BP regulation after intermittent WE in this patient group. METHODS Twenty patients with IC participated in two experimental sessions in a random order, as follows: WE (15 × 2-min bouts of WE interpolated with 2-min rest intervals) and control (standing rest on a treadmill for 60 min). BP, cardiac output (CO: CO2 rebreathing), and cardiovascular autonomic modulation (spectral analysis of HR variability) were assessed before and after both experimental sessions during supine rest, and stroke volume (SV) and systemic vascular resistance (SVR) were calculated. Data were analyzed using two-way ANOVA. RESULTS WE decreased systolic, diastolic, and mean BP, with net effects of -13 ± 2, -5 ± 2, and -7 ± 2 mm Hg versus control, respectively (all P < 0.05). WE also decreased SV (-5.62 ± 1.97 mL, P < 0.05) and CO (-0.05 ± 0.13 L·min(-1), P < 0.05) versus preintervention and prevented the observed increase in SVR in the control condition (+4.2 ± 1.4 U, P < 0.05). HR showed a decrease (P < 0.05), consistent with evidence of increased vagal modulation, in the control condition. BP measurements over the subsequent 24 h were similar between experimental conditions. CONCLUSIONS In patients with IC, WE induced a postexercise hypotension response that had a significant magnitude versus control but was not maintained over the next 24 h of daily activities. The acute postexercise hypotension response was mediated by a decrease in CO and SV, which was not compensated by an augmentation of SVR, as observed in the control arm of the study.

Predictors of walking capacity in peripheral arterial disease patients

OBJECTIVE: To estimate walking capacity in intermittent claudication patients through a prediction model based on clinical characteristics and the walking impairment questionnaire. METHODS: The sample included 133 intermittent claudication patients of both genders aged between 30 and 80 years. Data regarding clinical characteristics, the walking impairment questionnaire and treadmill walking test performance were obtained. Multiple regression modeling was conducted to predict claudication onset distance and total walking distance using clinical characteristics (age, height, mass, body mass index, ankle brachial index lower, gender, history of smoking and co-morbid conditions) and walking impairment questionnaire responses. Comparisons of claudication onset distance and total walking distance measured during treadmill tests and estimated by a regression equation were performed using paired t-tests. RESULTS: Co-morbid conditions (diabetes and coronary artery disease) and questions related to difficulty in walking short distances (walking indoors – such as around your house and walking 5 blocks) and at low speed (walking 1 block at average speed – usual pace) resulted in the development of new prediction models high significant for claudication onset distance and total walking distance (p<0.001). In addition, non-significant differences from the results obtained by the treadmill test and estimated by the current model (p>0.05) were observed. CONCLUSION: The current study demonstrated that walking capacity can be adequately estimated based on co-morbid conditions and responses to the walking impairment questionnaire.

Exercise prescription using the heart of claudication pain onset in patients with intermittent claudication

OBJECTIVE: To assess the acute metabolic and cardiovascular responses to walking exercise at an intensity corresponding to the heart rate of claudication pain onset and to investigate the effects of a 12-week walking training program at this intensity on walking capacity. METHODS: Twenty-nine patients with intermittent claudication were randomly allocated to the walking training (n = 17) or control (CO, n = 12) group. The walking training group performed an acute exercise session comprising 15×2-min bouts of walking at the heart rate of claudication pain onset, with 2-min interpolated rest intervals. The claudication symptoms and cardiovascular and metabolic responses were evaluated. Walking training was then performed at the same intensity twice each week for 12 weeks, while the control group engaged in twice weekly stretching classes. The claudication onset distance and total walking distance were evaluated before and after the interventions. Brazilian Registry Clinical Trials: RBR-7M3D8W. RESULTS: During the acute exercise session, the heart rate was maintained within tight limits. The exercise intensity was above the anaerobic threshold and >80% of the heart rate peak and VO2peak. After the exercise training period, the walking exercise group (n = 13) showed increased claudication onset distance (309±153 vs. 413±201m) and total walking distance (784±182 vs. 1,100±236m) compared to the control group (n = 12) (p<0.05). CONCLUSION: Walking exercise prescribed at the heart rate of claudication pain onset enables patients with intermittent claudication to exercise with tolerable levels of pain and improves walking performance.

Pain Threshold Is Achieved at Intensity Above Anaerobic Threshold in Patients With Intermittent Claudication

PURPOSE Walking training is considered as the first treatment option for patients with peripheral arterial disease and intermittent claudication (IC). Walking exercise has been prescribed for these patients by relative intensity of peak oxygen uptake (VO2peak), ranging from 40% to 70% VO2peak, or pain threshold (PT). However, the relationship between these methods and anaerobic threshold (AT), which is considered one of the best metabolic markers for establishing training intensity, has not been analyzed. Thus, the aim of this study was to compare, in IC patients, the physiological responses at exercise intensities usually prescribed for training (% VO2peak or % PT) with the ones observed at AT. METHODS Thirty-three IC patients performed maximal graded cardiopulmonary treadmill test to assess exercise tolerance. During the test, heart rate (HR), VO2, and systolic blood pressure were measured and responses were analyzed at the following: 40% of VO2peak; 70% of VO2peak; AT; and PT. RESULTS Heart rate and VO2 at 40% and 70% of VO2peak were lower than those at AT (HR: −13 ± 9% and −3 ± 8%, P < .01, respectively; VO2: −52 ± 12% and −13 ± 15%, P < .01, respectively). Conversely, HR and VO2 at PT were slightly higher than those at AT (HR: +3 ± 8%, P < .01; VO2: +6 ± 15%, P = .04). None of the patients achieved the respiratory compensation point. CONCLUSION Prescribing exercise for IC patients between 40% and 70% of VO2peak will induce a lower stimulus than that at AT, whereas prescribing exercise at PT will result in a stimulus above AT. Thus, prescribing exercise training for IC patients on the basis of PT will probably produce a greater metabolic stimulus, promoting better cardiovascular benefits.

Effects of Clustered Comorbid Conditions on Walking Capacity in Patients with Peripheral Artery Disease

BACKGROUND Comorbid conditions are known to increase cardiovascular risk in patients with peripheral artery disease (PAD). However, whether comorbid conditions affect walking capacity remains controversial. Previous studies have analyzed comorbidities separately, but they are known to occur in a clustered fashion in PAD patients. Therefore, the aim of this study was to analyze the influence of clustered comorbid conditions on walking capacity in PAD patients. METHODS This cross-sectional study included 415 PAD patients (155 women and 260 men with an average age of 63 years). Claudication distance and total walking distance were assessed with the graded maximal treadmill test. Medical histories of hypertension, diabetes, cerebrovascular disease (CVD), coronary artery disease (CAD), and chronic obstructive pulmonary disease (COPD) were obtained. Binary logistic regression was carried out to analyze whether clustered comorbid conditions were associated with walking capacity. RESULTS CVD was associated with lower total walking distance (odds ratio [OR] = 2.45; 95% confidence interval [CI]: 1.11-5.39). The cluster hypertension, diabetes, CVD, CAD, and COPD were associated with a lower claudication distance (OR = 7.63; 95% CI: 1.42-40.96). In addition, the clusters of CVD and hypertension (OR = 3.16; 95% CI: 1.38-7.23), CVD and CAD (OR = 3.46; 95% CI: 1.25-9.57), CVD, hypertension, and diabetes (OR = 11.38; 95% CI: 2.27-57.00) were associated with a lower total walking distance. CONCLUSIONS CVD was associated with walking impairment of IC patients and in particular when CVD is clustered with other comorbid conditions.