Table 1.
Summary of respiratory function tests and diagnostic sleep study findings
| n | Whole group | Type1 | Type 2 | Type 3 | P value* (types 2‐3) | |
|---|---|---|---|---|---|---|
| Age, y | 25 | 8.96 | 0.22 (5.44) | 9.30 (5.63) | 8.57 (4.67) | .90 |
| Male/female | 25 | 15/10 | 1 | 10/5 | 4/3 | .68 |
| FVC, L | 21 | 1.07 (1.01) | 0.69 | 0.87 (0.33) | 1.9 (0.63) | <.001 |
| FVC % predicted | 21 | 62 (53.2) | 57 | 51.25 (41.7) | 91.9 (12.00) | <.01 |
| FVC z‐score | 21 | −3.27 (4.74) | −3.4 | −4.27 (4.22) | −0.66 (1.09) | <.02 |
| Rsr8 z‐score | 18 | 0.77 (1.64) | – | 1.39 (1.92) | 0.29 (1.32) | <.02 |
| Xrs8 z‐score | 18 | 0.73 (1.46) | – | 1.28 (1.37) | −0.12 (0.62) | <.01 |
| LCI | 15 | 7.39 (1.74) | – | 8.06 (2.44) | 7.29 (0.55) | .13 |
| SNIP z‐score | 14 | −2.06 (2.87) | – | −2.53 (2.61) | −1.32 (2.47) | .33 |
| MIP z‐score | 12 | −0.36 (1.82) | – | −0.52 (1.57) | 0.19 (0.87) | .28 |
| MEP z‐score | 12 | −1.75 (2.2) | – | −1.76 (2.43) | −1.06 (2.22) | .53 |
| PCF, L/min | 14 | 231.9 (181.8) | – | 178.8 (246.0) | 277.8 (124.8) | .23 |
| Total AHI | 25 | 3.1 (4.9) | 7.6 (4.3) | 2.9 (2.4) | 3.1 (3.5) | .84 |
| REM AHI | 25 | 5.8 (9.1) | 20.0 (45.7) | 5.8 (9.9) | 4.6 (6.4) | .49 |
| Maximum TcCO2 | 25 | 47.8 (4.90) | 43.0 (6.20) | 48.2 (4.70) | 47.8 (6.70) | .49 |
Note: Data are presented as median (IQR).
Abbreviations: AHI, apnea‐hypopnea index; FVC, forced vital capacity; IQR, interquartile range; LCI, lung clearance index; MEP, maximal expiratory pressure; MIP, maximal inspiratory pressure; PCF, peak cough flow; REM, rapid eye movement sleep; Rrs8, resistance at 8 Hz; SNIP, sniff nasal inspiratory pressure; TcCO2, transcutaneous carbon dioxide level; Xrs8, reactance at 8 Hz.
*
P values are calculated for the difference between type 2 and 3 spinal muscular atrophy patients.