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. (C) 2010 Elsevier B.V. All rights reserved.