Investigação das alterações osteo-metabolicas e cardio-respiratorias ocorridas apos o treinamento de marcha sob estimulação eletrica neuromuscular em individuos tetraplegicos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Quadriplegic subjects present an extensive muscle mass paralysis and sympathetic autonomic impairment, which are mainly responsible for the dramatic decrease of bone mass and physical deconditioning, increasing the risk for medical complications. Exercise can improve physical conditioning associated to the likely positive effect on bone mass. The present study evaIuated the effect of treadmill gait training, with 30-500-foof weight relie( associated to neuromuscular electricaI stimulation, on bone mass and on metabolic and cardiorespiratory responses of quadriplegic subjects. Twenty two subjects with tetraplegia (levels within C4-C8) and three hea1thy individuaIs participated in this study. They were separated into 3 groups: group 1 performed treadmill gait training (12 subjects), group 2 did not perform gait training (10 subjects), and results ITomgroup 3 were used as comparisons (3 subjects). Metabolic and cardiorespiratory responses [oxygen uptake (VO2), carbon dioxide production (VCO2), pulmonary ventilation (VE), respiratory exchange rate (RER), heart rate (HR.)] and bone responses [using dual-energy X-ray absorptiometry (DEXA) of lumbar spine, femoraI neck, trochanteric area and total femur as well as biochemical markers of bone metabolism (osteocalcin, bone aIkaline phosphatase, pyridinoline and deoxipyridinoline)] were measured. Analyses were performed on inclusion and after 6 months. IndividuaIs ITomgroup 1 performed gait training during six months, twice a week, 20 minutes each session. Data :ITombone responses were ana1yzed individually due to the large individual variations. Results have shown that in the group 1, 75% presented a significant increase of bone formation markers; 66,67% aIso presented a significant decrease of bone resorption markers. In the control group, 300-fof individuaIs did not present any change of bone markers and only 200-foof individuais presented an increase of bone formation markers. Results obtained with biochemicaI markers were not always reproduCed in the BMD. Indeed, many individuaIs who presented an increase of bone formation markers presented a decrease ofBMD. Since DEXA technique has an error of precision associated to other difficulties during exams of spinaI cord injured persons (spasticity and difficulty to reproduce the same position of the lower limbs) and biochemical markers have been extensively used towards analyzing bone changes after short periods of treatment, the lack of correlation between biochemicaI markers and BMD suggests that data obtained by DEXA shall be carefully evaIuated. Results :ITom cardiorespiratory tests have shown significant differences in all parameters ana1yzed after gait training (p<0.05), except for HR: increase of 36% in VO2 Vmin, 42.97% in VCO2, 2.82% in HR, 30.48% in VE and 4.93% in RER For group 2, on1yVO2 Vmin increased significantly (26.290/c.)afier the 6 months período Although VO2 values did increase for group 2, they were significantly lower than those reached by group 1, which performed treadmill gait. Treadmill gait with NMES was therefore more efficient towards increasing aerobic capacity due to yielding higher metabolic and cardiovascular stresses. Moreover, results ftom bone markers have shown that the treadmill gait training, even with 30-500/c.of body relief, was efficient to promote biomechanical stress in order to stimulate bone formation process.

ASSUNTO(S)

osteoporose imunoensaio - metodo exercicios - fisiologia densitometria

ACESSO AO ARTIGO

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