TY - JOUR
T1 - Reduced exercise capacity in early-stage amyotrophic lateral sclerosis
T2 - Role of skeletal muscle
AU - Mezzani, Alessandro
AU - Pisano, Fabrizio
AU - Cavalli, Alessandra
AU - Tommasi, Maria Antonietta
AU - Corr, Ugo
AU - Colombo, Silvia
AU - Grassi, Bruno
AU - Marzorati, Mauro
AU - Porcelli, Simone
AU - Morandi, Lucia
AU - Giannuzzi, Pantaleo
PY - 2012/1
Y1 - 2012/1
N2 - Our objective was to correlate skeletal muscle mass (SM) with cardiopulmonary exercise testing (CPET) descriptors of exercise capacity in patients with amyotrophic lateral sclerosis (ALS) and compare ALS CPET data with those of patients with mitochondrial myopathy (MM) and normal subjects (N). Twenty-four early-stage ALS patients (63±11 years) underwent bioelectrical impedance analysis of body composition, resting spirometry, and ramp CPET. Six MM and six N were used as controls (56 ± 7 and 63 ± 4 years, respectively). Results showed that ALS SM index was similar to that of N (9.0±2.1 kg/m 2 vs. 10.4±1.9 kg/m 2, respectively; p = n.s.), whereas peak VO2/kg SM was significantly lower (41.5 ± 11.6 ml/kg/min vs. 57.8 ± 7.5 ml/kg/min, respectively; p <0.01). However, the heart rate/VO2 slope did not differ between ALS and N, being significantly higher in MM than in both ALS and N (6.1 ± 1.4 beats/ml/kg/min vs. 4.2 ± 1.1 beats/ml/kg/min vs. 3.8 ± 2.0 beats/ml/kg/min, respectively; both p <0.01), excluding a marked skeletal muscle metabolic impairment in ALS. Neither cardiovascular nor ventilatory dysfunction was detected in ALS. Early-stage ALS patients show a SM similar to N, but with a reduced peak VO2/kg SM. Such a reduced peripheral O2 utilization is consistent with deconditioning as the main cause of impaired exercise capacity in this population.
AB - Our objective was to correlate skeletal muscle mass (SM) with cardiopulmonary exercise testing (CPET) descriptors of exercise capacity in patients with amyotrophic lateral sclerosis (ALS) and compare ALS CPET data with those of patients with mitochondrial myopathy (MM) and normal subjects (N). Twenty-four early-stage ALS patients (63±11 years) underwent bioelectrical impedance analysis of body composition, resting spirometry, and ramp CPET. Six MM and six N were used as controls (56 ± 7 and 63 ± 4 years, respectively). Results showed that ALS SM index was similar to that of N (9.0±2.1 kg/m 2 vs. 10.4±1.9 kg/m 2, respectively; p = n.s.), whereas peak VO2/kg SM was significantly lower (41.5 ± 11.6 ml/kg/min vs. 57.8 ± 7.5 ml/kg/min, respectively; p <0.01). However, the heart rate/VO2 slope did not differ between ALS and N, being significantly higher in MM than in both ALS and N (6.1 ± 1.4 beats/ml/kg/min vs. 4.2 ± 1.1 beats/ml/kg/min vs. 3.8 ± 2.0 beats/ml/kg/min, respectively; both p <0.01), excluding a marked skeletal muscle metabolic impairment in ALS. Neither cardiovascular nor ventilatory dysfunction was detected in ALS. Early-stage ALS patients show a SM similar to N, but with a reduced peak VO2/kg SM. Such a reduced peripheral O2 utilization is consistent with deconditioning as the main cause of impaired exercise capacity in this population.
KW - Amyotrophic lateral sclerosis
KW - Muscle metabolism
KW - Oxygen consumption
KW - Skeletal muscle
KW - Ventilation
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U2 - 10.3109/17482968.2011.601463
DO - 10.3109/17482968.2011.601463
M3 - Article
C2 - 21830991
AN - SCOPUS:84855393924
VL - 13
SP - 87
EP - 94
JO - Amyotrophic Lateral Sclerosis and Other Motor Neuron Disorders
JF - Amyotrophic Lateral Sclerosis and Other Motor Neuron Disorders
SN - 1466-0822
IS - 1
ER -