| Characteristics | All subjects | ES⩾11 | ES<11 | MSL⩽8 min | MSL>8 min |
| Age in years, mean (SD) | 49.7 (10.0) | 46.7 (10.1) | 52.7 (9.4) | 48.8 (6.9) | 50.3 (12.1) |
| BMI in kg/m2, mean (SD) | 28.7 (6.4) | 29.4 (8.3) | (27.8) 3.8 | 28.3 (6.7) | 29.0 (6.3) |
| MIRS grade, mean (SD) | 3.3 (1.1) | 3.3 (1.0) | 3.3 (1.2) | 3.9 (0.7)* | 2.9 (1.2) |
| Depression T score, mean (SD) | 52.6 (9.2) | 53.9 (7.9) | 51.0 (10.6) | 52.5 (9.7) | 52.7 (9.0) |
| WAIS FSIQ, mean (SD) | 81.9 (8.8) | 82.8 (8.2) | 81.9 (8.9) | 80.9 (6.7) | 82.7 (10.2) |
| CTG repeats, mean (SD) | 868 (552) | 677 (494)* | 1010 (532) | 1000 (545) | 764 (546) |
| Habitual bedtime (h:min) | 23:44 (1:23) | 23:19 (1:09)* | 00:09 (1:29) | 23:56 (1:08) | 23:34 (1:32) |
| Habitual waketime (h:min) | 9:10 (1:30) | 9:19 (1:31) | 9:00 (1:30) | 9:25 (1:20) | 8:58 (1:36) |
| Habitual time in bed (h:min) | 9:26 (1:25) | 10:00 (1:17)** | 8:52 (1:20) | 9:29 (1:45) | 9:23 (1:10) |
| Cataplexy (%) | 23.3 | 43.0** | 5.0 | 32.0 | 17.0 |
| Sleep paralysis (%) | 32.6 | 52.0** | 14.0 | 47.0 | 21.0 |
| Hypnagogic hallucinations (%) | 23.3 | 33.0 | 14.0 | 26.0 | 21.0 |
*p<0.05; **p<0.01.
DM1, myotonic dystrophy type 1; ES, Epworth Sleepiness Scale scores; MIRS, muscular impairment rating scale; MSL, mean sleep latency; WAIS FSIQ, WAIS Full Scale IQ.