Table 2.
Spirometry Parameters Split by Presence and Severity of Obstructive Sleep Apnoea (OSA)
| Spirometry Parameters | No-OSA (n=27) | Mild OSA (n=57) | p-value | Moderate OSA (n=51) | p-value | Severe OSA (n=113) | p-value | |
|---|---|---|---|---|---|---|---|---|
| Age | Years | 43.62 (32.3, 51.69) | 50.68 (39.48, 60.21) | 0.036* | 52.13 (44.45, 57.43) | 0.013* | 46.14 (36.9, 55.41) | 0.412 |
| Sex | Female | 20 (74%) | 39 (68%) | 0.597 | 29 (57%) | 0.139 | 31 (36%) | 0.001* |
| Height | cms | 164 (160, 170) | 165 (160, 170) | 0.665 | 164.3 (160, 172) | 0.899 | 170 (163.5, 175.5) | 0.005* |
| Weight | kgs | 88 (71, 98.6) | 88.5 (79.5, 101.1) | 0792 | 95.2 (87, 106.1) | 0.185 | 110 (91, 122) | <0.001* |
| BMI | kg/m2 | 31.38 (27.44, 34.12) | 31.62 (28.53, 36.43) | 0.657 | 34.14, (30.9, 38.95) | 0.122 | 37.59 (31.38, 42.33) | 0.001* |
| FVC | LLN | 2.81 (2.49, 3.05) | 2.57 (2.25, 3.1) | 0.261 | 2.62 (2.37, 3.33) | 0.388 | 3.17 (2.59, 3.66) | 0.067 |
| Pre-BD (L) | 2.91 (2.04, 3.29) | 2.54 (2.03, 3.32) | 0.199 | 2.54 (2.11, 3.49) | 0.203 | 2.89 (2.26, 3.84) | 0.933 | |
| Pre-BD (%) | 0.85 (0.62, 0.93) | 0.8 (0.61, 0.89) | 0.304 | 0.79 (0.66, 0.91) | 0.275 | 0.77 (0.64, 0.88) | 0.111 | |
| Post-BD (L) | 2.93 (2.1, 3.38) | 2.61 (1.92, 3.39) | 0.226 | 2.61 (2.25, 3.44) | 0.228 | 2.96 (2.24, 3.82) | 0.895 | |
| Post-BD (%) | 0.88 (0.65, 0.97) | 0.82 (0.67, 0.92) | 0.211 | 0.79 (0.65, 0.93) | 0.062 | 0.77 (0.65, 0.89) | 0.021* | |
| FEV1 | LLN | 2.31 (1.98, 2.44) | 2.07 (1.77, 2.45) | 0.196 | 2.1 (1.87, 2.56) | 0.264 | 2.53 (2.09, 2.93) | 0.225 |
| Pre-BD (L) | 2.48 (1.65, 2.73) | 1.92 (1.49, 2.59) | 0.035* | 2.1 (1.57, 2.7) | 0.159 | 2.28 (1.66, 3) | 0.411 | |
| Pre-BD (%) | 0.84 (0.69, 0.94) | 0.78 (0.58, 0.9) | 0.309 | 0.77 (0.62, 0.91) | 0.235 | 0.76 (0.6, 0.89) | 0.151 | |
| Post-BD (L) | 2.46 (1.75, 2.84) | 2.06 (1.43, 2.62) | 0.106 | 2.17 (1.65, 2.71) | 0.250 | 2.44 (1.79, 3.15) | 0.939 | |
| Post-BD (%) | 0.9 (0.66, 0.98) | 0.82 (0.6, 0.91) | 0.286 | 0.81 (0.63, 0.93) | 0.255 | 0.78 (0.6, 0.91) | 0.072 | |
| FEV1/FVC | LLN | 0.72 (0.71, 0.73) | 0.71 (0.69, 0.73) | 0.062 | 0.71 (0.69, 0.72) | 0.067 | 0.71 (0.7, 0.73) | 0.210 |
| Pre-BD (absolute) | 0.81 (0.76, 0.85) | 0.79 (0.73, 0.83) | 0.240 | 0.8 (0.76, 0.83) | 0.543 | 0.79 (0.73, 0.83) | 0.266 | |
| Post-BD (absolute) | 0.83 (0.8, 0.88) | 0.81 (0.74, 0.84) | 0.168 | 0.81 (0.76, 0.85) | 0.174 | 0.82 (0.75, 0.86) | 0.356 | |
| BDR | Yes | 5 (19%) | 6 (11%) | 0.316 | 4 (8%) | 0.172 | 10 (9%) | 0.154 |
| Impairment | Restrictive | 7 (26%) | 23 (40%) | 0.201 | 19 (37%) | 0.315 | 46 (41%) | 0.160 |
| Obstructive | 1 (4%) | 2 (4%) | 0.964 | 1 (2%) | 0.649 | 3 (3%) | 0.770 | |
| Mixed | 2 (7%) | 3 (5%) | 0.699 | 6 (12%) | 0.550 | 13 (12%) | 0.540 | |
| Normal spirometry | 17 (63%) | 29 (51%) | 0.300 | 25 (49%) | 0.242 | 51 (45%) | 0.100 | |
Notes: Data were median (interquartile range) or number (%). p-values obtained via univariate quantile regression for continuous outcomes or univariate logistic regression for binary outcomes utilising “Non-OSA” as baseline reference. *Indicates significance at p<0.05.
Abbreviations: BD, bronchodilator; BDR, BD response; FEV1, Forced expiratory volume in 1 second; FVC, Forced vital capacity; LLN, Lower limit of normal.