Table 1.

Baseline characteristics

	ALS group, n = 30	Non-ALS group, n = 47
Diagnosis	Amyotrophic lateral sclerosis	Neuromuscular disease (n = 42) Thoracic cage problem (n = 5)
Age (years)	59.6 ± 10.6	57.7 ± 14.7
Male (%)	66.7	53.2
PaCO2 (kPa)	6.6 ± 0.8	6.6 ± 1.0
PaO2 (kPa)	10.4 ± 0.9	9.6 ± 1.6
BMI (kg/m2)	23.8 ± 5.2	28.9 ± 6.4
Packyears	27.8 ± 19.4	18.9 ± 14.4

Data are presented as mean ± standard deviation

kPa kilo Pascal, PaCO ₂ partial pressure of arterial carbon dioxide, PaO ₂ partial pressure of arterial oxygen, BMI body mass index