Table 8.
Multivariable linear regression models of independent associations of changes in tonsil/adenoid size and % changes in polysomnographic parameters in the outcome analysis.
| Outcome variables | Independent variables | β (95% CI) | VIF | P Value | Adjusted R2 |
|---|---|---|---|---|---|
| Clinical variables | |||||
| Change in tonsil size | % Change in OSA-18 score | 0.01 (0.002–0.01) | 1.10 | 0.005 | 0.309 |
| % Change in OAHI | 0.002 (0.001–0.004) | 1.11 | 0.005 | ||
| HF power | 0.001 (0.0001–0.002) | 1.03 | 0.025 | ||
| Change in ANR | Age at diagnosis | 0.01 (0.001–0.03) | 1.06 | 0.030 | 0.203 |
| Male sex | 0.06 (0.004–0.12) | 1.04 | 0.037 | ||
| % Change in arousal index | −0.0002 (-0.0004-−0.0003) | 1.02 | 0.026 | ||
| Subjective sleep quality (polysomnographic parameters) | |||||
| % Change in OAHI | Change in tonsil size | 65.79 (32.37–99.20) | 1.00 | < 0.001 | 0.189 |
| % Change in OAI | None | ||||
| % Change in arousal index | Change in ANR | −317.27 (-593.74-−40.794) | 1.02 | 0.025 | 0.329 |
| % Change in LF power | 0.84 (0.49–1.18) | 1.02 | < 0.001 | ||
| % Change in mean SaO2 | Age at diagnosis | −0.17 (-0.31-−0.03) | 1.05 | 0.020 | 0.296 |
| % Change in N-N interval | −0.05 (-0.08-−0.03) | 1.74 | < 0.001 | ||
| % Change in pNN50 | 0.004 (0.002–0.01) | 1.78 | 0.002 | ||
| % Change in LF power | 0.004 (0.001–0.01) | 1.55 | 0.024 | ||
| % Change in minimal SaO2 | None | ||||
| % Change in N1 sleep | % Change in LF power | 0.55 (0.21–0.88) | 1.00 | 0.002 | 0.138 |
| % Change in N2 sleep | None | ||||
| % Change in N3 sleep | % Change in LF/HF ratio | 0.09 (0.002–0.18) | 1.00 | 0.045 | 0.050 |
| % Change in REM sleep | % Change in VLF power | −0.17 (-0.34-−0.004) | 1.00 | 0.045 | 0.048 |
| % Change in TST | % Change in LF power | 0.17 (0.02–0.32) | 1.00 | 0.031 | 0.060 |
BMI, body mass index; CI, confidence interval; HF, high frequency; LF, low frequency; OAHI, obstructive apnea-hypopnea index; OAI, obstructive apnea index; OSA, obstructive sleep apnea; N-N, normal-to-normal; pNN50, proportion of N-N50 divided by the total number of N-N intervals; REM, rapid eye movement; SaO2, blood oxygen saturation; TST, total sleep time; VIF, variance inflation factor; VLF, very low frequency.