Charcot-Marie-Tooth 1A patients with low level of impairment have a higher energy cost of walking than healthy individuals

The study aimed at quantifying the walking energy cost of a group of Charcot-Marie-Tooth 1A patients (CMT1A), with low severity of walking impairment, in comparison with healthy individuals. Oxygen uptake was measured in 8 patients (age-range 20–48 years; Barthel >90; Tinetti >20) and 8 healthy individuals, matched for age and gender, when walking on a circuit for 5-min at their self-selected speeds (“slow”, “comfortable” and “fast”). Both comfortable and fast speeds were lower in patients than in the control group (0.92 ± 0.16 vs 1.16 ± 0.22 and 1.27 ± 0.27 vs 1.61 ± 0.22 m s−1, respectively; P < 0.05), whereas walking energy cost per unit of distance was higher in patients than in the control group (P < 0.05) at both “comfortable” (2.27 ± 0.35 vs 1.92 ± 0.21 J kg−1 m−1) and “fast” speed (3.05 ± 0.35 vs 2.37 ± 0.42 J kg−1 m−1). CMT1A patients, therefore, choose to walk slower but with higher metabolic cost compared to healthy individuals, despite no clinically evident walking impairment, which is likely due to altered walking patterns.