Table 3.
Sleep stage durations by dosage group and biological time of scheduled sleep opportunity. Mean (and standard deviation) for each sleep stage are presented in minutes, along with sleep efficiency and number of awakenings; model-fit group difference estimates (and standard error) are presented, as are T values and p values for the dosage group comparisons. Biological Night: sleep opportunities beginning between 240 and 90 degrees; Biological Day: sleep opportunities beginning between 90 and 240 degrees. Top Panel: Placebo vs. Low Dose (0.3 mg) Melatonin; Bottom Panel: Placebo vs. High Dose (5.0 mg) Melatonin.
| Biological Night | Biological Day | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Placebo mean (std dev) | Low Dose mean (std dev) | Estimate (std err) | T value (df=144) | P-value | Placebo mean (std dev) | Low Dose mean (std dev) | Estimate (std err) | T value (df=109) | P-value | |
| Sleep Efficiency(%) | 78.54 (6) | 80.37 (5.54) | 1.44 (1.88) | 0.77 | 0.4449 | 62.3 (10.03) | 66.69 (11.12) | 4.55 (2.58) | 1.76 | 0.0804 |
| Stage 1 (min) | 35.4 (17.62) | 39.48 (23.0) | 4.36 (2.06) | 2.12 | 0.036 | 32.85 (16.24) | 37.54 (25.37) | 4.60 (2.51) | 1.83 | 0.0703 |
| Stage 2 (min) | 149.29 (21.03) | 160.2 (21.03) | 10.89 (5.67) | 1.92 | 0.0569 | 122.84 (26.57) | 140.04 (29.81) | 16.62 (6.88) | 2.42 | 0.0174 |
| Stage SWS (min) | 47.72 (26.64) | 43.82 (27.8) | −3.89 (2.40) | −1.62 | 0.1075 | 45.58 (21.65) | 38.91 (25.94) | −6.68 (2.43) | −2.75 | 0.007 |
| Stage NREM (min) | 232.41 (18.82) | 243.5 (19.85) | 10.44 (6.04) | 1.73 | 0.086 | 201.28 (34.49) | 216.48 (43.63) | 14.95 (8.44) | 1.77 | 0.0794 |
| Stage REM (min) | 81.07 (15.32) | 77.47 (16.52) | −3.83 (2.98) | −1.29 | 0.1997 | 47.16 (11.72) | 49.69 (14.18) | 3.30 (3.04) | 1.09 | 0.2803 |
| TST (min) | 313.48 (23.89) | 320.97 (22.16) | 5.89 (7.48) | 0.79 | 0.4323 | 248.44 (39.78) | 266.17 (44.17) | 18.37 (10.27) | 1.79 | 0.0765 |
| Stage Wake (min) | 85.68 (24.01) | 78.46 (21.9) | −5.65 (7.49) | −0.76 | 0.4515 | 150.51 (40.25) | 131.62 (44.70) | −19.64 (10.16) | −1.93 | 0.0558 |
| Latency (min) | 19.32 (19.02) | 12.69 (5.4) | −7.52 (6.37) | −1.18 | 0.2397 | 20.94 (12.17) | 23.33 (15.57) | 2.29 (3.62) | 0.63 | 0.5283 |
| Number of awakenings | 23.59 (8.27) | 25.38 (10.69) | 0.07 (0.03) | 2.13 | 0.0349 | 23.93 (10.53) | 23.28 (10.48) | −0.03 (0.04) | −0.68 | 0.497 |
| Duration of awakenings (min) | 4.46 (2.15) | 3.65 (168) | 0.23 (0.14) | 2.66a | 0.1026 | 8.34 (4.75) | 7.38 (3.99) | 0.13 (0.16) | 0.65a | 0.4185 |
| Placebo mean (std dev) | High Dose mean (std dev) | Estimate (std err) | T value (df=148) | P-value | Placebo mean (std dev) | High Dose mean (std dev) | Estimate (std err) | T value (df=111) | P-value | |
| Sleep Efficiency (%) | 76.68 (7.62) | 80.67 (4.52) | 3.89 (185) | 2.1 | 0.0374 | 60.47 (12.06) | 69.7 (9.02) | 8.87 (2.84) | 3.12 | 0.0023 |
| Stage 1 (min) | 38.68 (23.50) | 42.22 (20.07) | 2.89 (2.05) | 1.41 | 0.1604 | 34.33 (20.21) | 37.54 (19.52) | 3.85 (2.02) | 1.91 | 0.0591 |
| Stage 2 (min) | 130.68 (27.30) | 151.51 (21.39) | 20.74 (4.84) | 4.28 | <0.0001 | 105.93 (28.53) | 141.69 (27.28) | 34.01 (6.82) | 4.98 | <0.0001 |
| Stage SWS (min) | 58.18 (26.46) | 46.72 (22.77) | −11.14 (2.57) | −4.33 | <0.0001 | 50.25 (19.94) | 41.64 (22.18) | −8.03 (2.93) | −2.74 | 0.0071 |
| Stage NREM (min) | 227.54 (19.61) | 240.45 (15.95) | 12.53 (5.42) | 2.31 | 0.0224 | 190.51 (36.57) | 220.86 (26.80) | 29.78 (8.46) | 3.52 | 0.0006 |
| Stage REM (min) | 78.78 (17.27) | 81.78 (13.30) | 2.95 (3.32) | 0.89 | 0.3754 | 51.03 (15.12) | 57.5 (11.12) | 5.57 (3.84) | 1.45 | 0.1502 |
| TST (min) | 306.32 (30.37) | 322.24 (18.09) | 15.56 (7.40) | 2.1 | 0.0372 | 241.54 (48.24) | 278.37 (36.09) | 35.38 (11.35) | 3.12 | 0.0023 |
| Stage Wake (min) | 93.09 (30.22) | 77.11 (17.72) | −15.64 (7.43) | −2.1 | 0.037 | 157.89 (48.36) | 121.13 (36.17) | −35,28 (11.36) | −3.11 | 0.0024 |
| Latency (min) | 15.78 (10.53) | 11.52 (8.70) | −4.11 (2.16) | −1.9 | 0.0598 | 19.95 (11.11) | 23.25 (19.84) | 2.41 (4.25) | 0.57 | 0.5714 |
| Number of awakenings | 24.24 (10.78) | 24.02 (11.33) | −0.01 (0.03) | −0.17 | 0.8633 | 19.9 (9.27) | 25.22 (16.28) | 0.22 (0.04) | 5.72 | <0.0001 |
| Duration of awakenings (min) | 4.52 (3.01) | 3.37 (133) | 0.33 (0.19) | 3.09a | 0.0789 | 10.26 (5.08) | 6.63 (5.04) | 0.37 (0.20) | 3.40a | 0.0653 |
std dev=standard deviation; std err=standard error; df=degrees of freedom; min=minutes, SWS=slow wave sleep, NREM=non REM sleep, REM=rapid eye movement sleep;TST=total sleep time, SoL=sleep onset latency.
=chi-square statistic, df=1