Using data from the Canadian Neuromuscular Disease Registry, collected by 36 centres, a cross-sectional study of real-life respiratory data from 323 patients with Duchenne muscular dystrophy (DMD), aged between 2 and 36 years, showed that :
- almost one-fifth (19.5%) of 14-16 year olds were on ventilatory support, a proportion which rises to 69.2% at the age of 20-22 years;
- Vital capacity (VC) was above 80% in the majority of children up to the age of 10-12 years, while it generally fell below 50% around the age of 18-20 years;
- VC declined by an average of 3.19% per year; in 8-20 year-olds, the annual decline in VC was 2.47% per year in non-ambulatory children, compared with 0.96% in those who walked;
- there was no significant correlation between the state of the spine and the annual decline in VC, although it was 3.22% in those with scoliosis compared with 2.72% in those without VC.
