Sleep characteristics among MESA sleep ancillary study participants, N=1895
| Total N=1895* | White n=696 (37%) | Black n=531 (28%) | Hispanic/Latinx n=453 (24%) | Chinese n=215 (11%) | P value (for race/ethnicity differences) | |
| Sleep characteristics | ||||||
| Actigraphy-assessed sleep characteristics | ||||||
| Average sleep duration† | <0.001 | |||||
| <7 hours (short) | 1175 (63.1) | 362 (52.9) | 403 (76.7)‡ | 276 (62.2) | 134 (64.1) | |
| 7–9 hours (recommended) | 659 (35.4) | 311 (45.5) | 120 (23.0)‡ | 156 (35.1) | 72 (34.5) | |
| >9 hours (long) | 28 (1.5) | 11 (1.6) | 2 (0.4)‡ | 12 (2.7) | 3 (1.4) | |
| Very short sleep (≤5 hours) | 239 (12.8) | 54 (7.9) | 104 (19.8) | 48 (10.8) | 33 (15.8) | <0.001 |
| Average sleep maintenance efficiency§ | 0.043 | |||||
| <85% (low) | 103 (5.5) | 25 (3.7)‡ | 38 (7.2) | 26 (5.9) | 14 (6.7) | |
| ≥85% (recommended) | 1759 (94.5) | 659 (96.4)‡ | 487 (92.8) | 418 (94.1) | 195 (93.3) | |
| Average fragmentation index¶ | <0.001 | |||||
| >15% (high) | 1419 (76.2) | 481 (70.3) | 441 (84.0) | 346 (77.9) | 151 (72.3)‡ | |
| ≤15% (recommended) | 443 (23.8) | 203 (29.7) | 84 (16.0) | 98 (22.1) | 58 (27.8)‡ | |
| Insomnia symptoms (yes)** | 681 (35.9) | 245 (35.2) | 204 (38.4) | 173 (38.2) | 59 (27.4) | 0.025 |
| Polysomnography-assessed obstructive sleep apnoea (OSA)/resp. sleep disturbance (3% desaturations)†† | 0.110 | |||||
| None (0 to <5/hour) | 395 (20.8)‡ | 152 (21.8)‡ | 118 (22.2) | 78 (17.2) | 47 (21.9)‡ | |
| Minimal (5 to <15/hour) | 603 (31.8)‡ | 239 (34.3)‡ | 168 (31.6) | 130 (28.7) | 66 (30.7)‡ | |
| Mild/moderate (15 to 30/hour) | 476 (25.1)‡ | 167 (24.0)‡ | 131 (24.7) | 129 (28.5) | 49 (22.8)‡ | |
| Severe (>30/hour) | 421 (22.2)‡ | 138 (19.8)‡ | 114 (21.5) | 116 (25.6) | 53 (24.7)‡ | |
| Sleep apnoea-specific hypoxic burden (SASHB)‡‡ mean ± SD, % min/hour | 56.5 (65.1) | 52.2 (50.5) | 53.6 (77.8) | 65.2 (70.0) | 59.8 (60.2) | |
| SASHB: means/SDs by quintile, % min/hour | ||||||
| Quintile 1: 0.02–16.24 | 8.8 (4.4) | 9.0 (4.1) | 8.5 (4.9) | 9.4 (4.0) | 8.3 (4.4) | |
| Quintile 2: 16.25–29.29 | 22.5 (3.7) | 22.7 (3.6) | 22.4 (3.7) | 22.1 (3.8) | 22.1 (3.8) | |
| Quintile 3: 29.30–47.74 | 37.8 (5.6) | 37.7 (5.4) | 37.4 (5.9) | 38.1 (5.2) | 38.6 (6.0) | |
| Quintile 4: 47.75–84.395 | 64.1 (10.9) | 62.2 (10.2) | 64.2 (11.0) | 65.9 (11.3) | 66.5 (11.4) | |
| Quintile 5: 84.3951–1099.61 | 149.8 (92.1) | 136.2 (60.4) | 166.4 (135.2) | 156.6 (87.4) | 139.8 (67.5) | |
| Box-Cox normalised SASHB: mean ± SD | 5.3 (2.1) | 5.3 (1.9) | 5.0 (2.3) | 5.6 (2.1) | 5.4 (2.2) | 0.111 |
| Sleep apnoea plus highest quintile of SASHB | 0.003 | |||||
| ≥15 episodes/hour and high SASHB | 370 (19.6) | 122 (17.5) | 88 (16.7) | 108 (23.9) | 52 (24.2) | |
| ≥15 episodes/hour or high SASHB | 534 (28.2) | 186 (26.7) | 158 (29.9) | 139 (30.8) | 51 (23.7) | |
| No apnoea and not high SASHB | 987 (52.2) | 388 (55.8) | 282 (53.4) | 205 (45.4) | 112 (52.1) | |
| Short sleep plus insomnia symptoms | <0.001 | |||||
| <7 hours and insomnia symptoms | 428 (23.2) | 122 (18.0) | 160 (30.5) | 108 (24.8) | 38 (18.5) | |
| <7 hours or insomnia symptoms | 987 (53.6) | 357 (52.7) | 283 (54.0) | 231 (53.1) | 116 (56.3) | |
| 7–9 hours, no insomnia symptoms | 427 (23.2) | 198 (29.3) | 81 (15.5) | 96 (22.1) | 52 (25.2) | |
| Short sleep plus low maintenance efficiency | <0.001 | |||||
| <7 hours and low maintenance efficiency | 90 (4.9) | 20 (3.0)‡ | 36 (6.9)‡ | 22 (5.1) | 12 (5.8) | |
| <7 hours or low maintenance efficiency | 1098 (59.9) | 347 (51.6)‡ | 369 (70.6)‡ | 258 (59.7) | 124 (60.2) | |
| 7–9 hours and efficient maintenance | 646 (35.2) | 306 (45.5)‡ | 118 (22.6)‡ | 152 (35.2) | 70 (34.0) | |
| Sleep apnoea plus fragmentation | <0.001 | |||||
| ≥15 episodes/hour and >15% frag | 724 (38.9)‡ | 237 (34.7)‡ | 213 (40.6) | 191 (43.0) | 83 (39.7) | |
| ≥15 episodes/hour or >15% frag. | 854 (45.9)‡ | 307 (44.9)‡ | 258 (49.1) | 205 (46.2) | 84 (40.2) | |
| No apnoea and ≤15% frag. | 284 (15.3)‡ | 140 (20.5)‡ | 54 (10.3) | 48 (10.8) | 42 (20.1) | |
| ‘Suboptimal’ sleep§§ | 1624 (87.2) | 569 (83.2) | 470 (89.5) | 404 (91.0) | 181 (86.6) | 0.001 |
| Feeling overly sleepy during the day¶¶ | <0.001 | |||||
| Never | 430 (23.0)‡ | 92 (13.3) | 91 (17.4)‡ | 158 (35.4) | 89 (42.2)‡ | |
| Rarely | 562 (30.1)‡ | 226 (32.7) | 181 (34.7)‡ | 102 (22.9) | 53 (25.1)‡ | |
| Sometimes | 557 (29.8)‡ | 245 (35.5) | 160 (30.7)‡ | 108 (24.2) | 44 (20.9)‡ | |
| Often | 232 (12.4)‡ | 101 (14.6) | 62 (11.9)‡ | 48 (10.8) | 21 (10.0)‡ | |
| Almost always | 89 (4.8)‡ | 27 (3.9) | 28 (5.4)‡ | 30 (6.7) | 4 (1.9)‡ |
*N with actigraphy data=1862: 684 white, 525 black, 444 Hispanic/Latinx and 209 Chinese.
†The average time spent asleep during main sleep periods (sum of all time asleep across recording divided by the total main sleep periods).
‡Rounded percentages do not add to 100.
§The average sleep maintenance efficiency in main sleeps (percentage of time spent asleep between falling asleep (sleep onset) and waking up (sleep offset)).
¶The sum of per cent mobile epochs and per cent immobile bouts less than 1 min duration to the number of immobile bouts for the given interval. Also known as the index of restlessness or movement and fragmentation index.
**Insomnia symptoms were based on self-reported questionnaire using a Women’s Health Initiative Insomnia Rating Scale score of ≥9 (range: 0–20).
††OSA/resp. sleep disturbance was measured using the Apnoea-Hypopnoea Index (AHI) ≥3% (ie, the number of all apnoeas and hypopnoeas with ≥3% oxygen desaturations per hour of sleep); OSA was defined as an AHI≥15 events per hour.
‡‡Hypoxic burden calculated as the area under the oxygen saturation curve associated with each individual respiratory (airflow) disruption (individual apnoeas and hypopnoeas). These individual burden measures are summed and divided by total sleep time.
§§‘Suboptimal’ sleep is coded positive if any of the following exists: short sleep (<7 hours), long sleep (>9 hours), low sleep maintenance efficiency (<85%), and insomnia symptoms.
¶¶Exam 4.
frag, fragmentation; MESA, Multi-Ethnic Study of Atherosclerosis.