Table 3.
Objective sleep parameters analysed by PSG.
| Parameter | Placebo (n = 21) |
RBS (n = 21) |
P valuea (Unadjusted) |
P valueb (Adjusted) |
|
|---|---|---|---|---|---|
| SE, % | At Baseline | 92.6 ± 4.8 | 91.4 ± 8.8 | 0.562 | |
| At 2 weeks | 91.0 ± 6.2 | 94.3 ± 4.0 | 0.051 | ||
| Difference | −1.6 ± 5.9 | 2.9 ± 7.7 | 0.037 | 0.019 | |
| TST, min | At Baseline | 362.6 ± 16.0 | 356.4 ± 34.4 | 0.460 | |
| At 2 weeks | 354.8 ± 24.02 | 368.1 ± 16.1 | 0.042 | ||
| Difference | −7.8 ± 21.0 | 11.7 ± 29.9 | 0.019 | 0.010 | |
| SL, min | At Baseline | 7.8 ± 5.3 | 9.7 ± 11.3 | 0.499 | |
| At 2 weeks | 10.7 ± 11.7 | 6.5 ± 4.6 | 0.140 | ||
| Difference | 2.9 ± 12.9 | −3.1 ± 11.7 | 0.122 | 0.047 | |
| REM sleep latency, min | At Baseline | 96.8 ± 43.4 | 92.4 ± 54.4 | 0.770 | |
| At 2 weeks | 86.5 ± 45.6 | 76.9 ± 40.0 | 0.473 | ||
| Difference | −10.4 ± 58.1 | −15.5 ± 56.8 | 0.774 | 0.983 | |
| WASO, min | At Baseline | 20.9 ± 16.5 | 24.1 ± 25.5 | 0.635 | |
| At 2 weeks | 24.5 ± 20.7 | 15.8 ± 14.8 | 0.126 | ||
| Difference | 3.5 ± 19.9 | −8.3 ± 23.3 | 0.084 | 0.071 | |
| TWT, % | At Baseline | 5.4 ± 4.2 | 6.9 ± 6.5 | 0.638 | |
| At 2 weeks | 6.3 ± 5.3 | 4.1 ± 3.8 | 0.126 | ||
| Difference | 0.9 ± 5.1 | −2.1 ± 6.0 | 0.084 | 0.072 | |
| Stage 1, % | At Baseline | 5.9 ± 2.2 | 7.4 ± 3.5 | 0.103 | |
| At 2 weeks | 6.1 ± 3.6 | 5.7 ± 2.4* | 0.721 | ||
| Difference | 0.2 ± 4.1 | −1.6 ± 3.5 | 0.125 | 0.117 | |
| Stage 2, % | At Baseline | 66.5 ± 5.9 | 65.3 ± 7.6 | 0.571 | |
| At 2 weeks | 64.0 ± 7.3 | 68.4 ± 4.3 | 0.022 | ||
| Difference | −2.5 ± 7.2 | 3.1 ± 8.0 | 0.022 | 0.020 | |
| Stage 3, % | At Baseline | 0.5 ± 2.2 | 0.0 ± 0.0 | 0.329 | |
| At 2 weeks | 0.6 ± 2.7 | 0.0 ± 0.0 | 0.329 | ||
| Difference | 0.1 ± 0.5 | 0.0 ± 0.0 | 0.329 | 0.361 | |
| REM sleep, % | At Baseline | 19.8 ± 5.0 | 18.7 ± 6.5 | 0.528 | |
| At 2 weeks | 20.3 ± 5.4 | 20.1 ± 5.5 | 0.917 | ||
| Difference | 0.5 ± 6.3 | 1.4 ± 5.9 | 0.611 | 0.450 | |
| Delta wave, % | At Baseline | 29.6 ± 5.0 | 28.8 ± 4.7 | 0.611 | |
| At 2 weeks | 29.5 ± 5.9 | 31.6 ± 9.2 | 0.387 | ||
| Difference | −0.1 ± 5.5 | 2.8 ± 10.1 | 0.262 | 0.067 | |
| RDI | At Baseline | 33.6 ± 16.6 | 29.1 ± 12.2 | 0.317 | |
| At 2 weeks | 36.5 ± 19.6 | 29.7 ± 12.4 | 0.186 | ||
| Difference | 2.9 ± 9.5 | 0.6 ± 5.8 | 0.357 | 0.256 | |
| AHI | At Baseline | 29.7 ± 18.7 | 22.9 ± 14.9 | 0.198 | |
| At 2 weeks | 33.0 ± 21.4 | 23.9 ± 15.8 | 0.122 | ||
| Difference | 3.3 ± 9.9 | 0.9 ± 6.3 | 0.366 | 0.361 | |
| Total AI | At Baseline | 29.8 ± 13.8 | 26.6 ± 9.6 | 0.373 | |
| At 2 weeks | 31.2 ± 15.1 | 26.7 ± 10.2 | 0.258 | ||
| Difference | 1.4 ± 7.9 | 0.10 ± 6.5 | 0.577 | 0.353 | |
Data are expressed as the mean ± standard deviation.
*Within-group comparison, paired t-test, P < 0.05.
aP values refer to independent t-tests, compared with the placebo group.
bP values refer to the analysis of covariance, adjusted for caffeine intake as a covariate.