Efeito do treinamento de caminhada sobre o risco, a função e a regulação cardiovasculares em indivíduos com claudicação intermitente

Abstract

Walking training (WT) is recommended for the treatment of patients with intermittent claudication (IC) because it improves walking capacity. Moreover, it would be interesting that WT also promotes beneficial changes on cardiovascular system, since cardiovascular events are the main causes of death in these patients. Nevertheless, the effects of WT on cardiovascular system in patients with IC have been poorly studied. Thus, the objective of this study was to investigate the effects of WT on cardiovascular risk, function and regulation in patients with IC. Forty-two IC patients were randomly divided into 2 groups: Control (CG, n=20, 30 min of stretching exercises) and walking training (TG, n=22, 15 sets of 2:2-min walk:rest at the heart rate (HR) of pain threshold). In both groups, the intervention was performed twice/week for 12 consecutive weeks. At the beginning and end of the study, the following measured were done: fasting glycemia and lipid profile; body mass index; walking capacity; VO 2 at the first stage and the peak of a treadmill test; ankle brachial index (ABI); ischemic window after maximal test; resting (auscultatory) and 24-hour (oscillometric) blood pressure (BP); cardiac output (CO-CO 2 rebreathing); heart rate (HR-ECG); stroke volume (SV); systemic, forearm and leg vascular resistance (VR-plethysmography); low-(LF) and high-frequency (HF) components of HR variability; and spontaneous baroreflex sensitivity (SBS). Significant changes (P<0.05) over time and between groups were assessed by 2-way ANOVA for repeated measures. WT significantly increased walking capacity (∆=+302±85m) and SBS (∆=+2.13±1.07 ms/mmHg), and decreased VO 2 at the first stage of treadmill test (∆=-1.8±0.4ml.kg-1 .min-1), ischemic window (∆=-0.40±0.38mmHg.min.m-1), mean BP (∆=-5±2mmHg), ambulatory mean BP variability (∆=-0,8±0,2 mmHg), CO (∆=-0.37±0.24 L/min), HR (∆=-4±2bpm), forearm VR (∆=-8.5±2.8 U) and LF/HF (∆=-1.24±0.99). Glycemia, lipid profile, body mass index, VO 2 peak, ABI, systemic and leg VR were unchanged following WT. There was no significant change for any variable in CG. In conclusion, WT enhanced walking capacity, walking economy and ischemic window. In addition, WT improved cardiovascular function (BP, CO, HR and forearm VR) and autonomic regulation (LF/HF, SBS) in patients with IC. These changes provide further support for the use of regular WT in treating patients with IC.