Table 2.
Participant characteristics by sleep duration categories: the Multi-Ethnic Study of Atherosclerosis (2010–2013), N = 2049
| Participant characteristics | Sleep duration categories, hr | P* | ||||
|---|---|---|---|---|---|---|
| <5.0 N = 267 |
5.0–5.9 N = 366 |
6.0–6.9 N = 649 |
7–8 N = 539 |
>8 N = 228 |
||
| Age, mean years ± SD | 69.2 ± 10.0 | 68.0 ± 9.0 | 67.6 ± 8.8 | 68.2 ± 9.0 | 71.7 ± 9.0 | 0.021 |
| Female, n (%) | 97 (36.3) | 185 (50.6) | 333 (51.3) | 335 (62.2) | 147 (64.5) | <0.001 |
| Race/ethnicity, n (%) | <0.001 | |||||
| Non-Hispanic white | 62 (23.2) | 90 (24.6) | 256 (39.5) | 258 (47.9) | 112 (49.1) | |
| Chinese-American | 36 (13.5) | 45 (12.3) | 65 (10.0) | 63 (11.7) | 18 (7.9) | |
| African American | 116 (43.5) | 130 (35.5) | 181 (27.9) | 96 (17.8) | 37 (16.2) | |
| Hispanic | 53 (19.9) | 101 (27.6) | 147 (22.7) | 122 (22.6) | 61 (26.8) | |
| Education, n (%) | 0.136 | |||||
| Less than a high school diploma | 35 (13.1) | 45 (12.3) | 82 (12.6) | 77 (14.3) | 48 (21.1) | |
| High school diploma or some college | 122 (45.7) | 175 (47.8) | 311 (47.9) | 242 (44.9) | 96 (42.1) | |
| College degree or higher | 110 (41.2) | 146 (39.9) | 256 (39.5) | 220 (40.8) | 84 (36.8) | |
| Married/living with partner, n (%) | 145 (54.3) | 201 (54.9) | 421 (64.9) | 346 (64.2) | 126 (55.3) | <0.001 |
| Smoking, n (%) | <0.001 | |||||
| Current | 35 (13.1) | 29 (7.9) | 46 (7.1) | 22 (4.1) | 20 (8.8) | |
| Former | 130 (48.7) | 164 (44.8) | 291 (44.8) | 265 (49.2) | 98 (43.0) | |
| Never | 102 (38.2) | 173 (47.3) | 312 (48.1) | 252 (46.8) | 110 (48.3) | |
| Presently drinking alcohol, n (%) | 107 (40.1) | 146 (39.9) | 303 (46.7) | 251 (46.6) | 87 (38.2) | 0.032 |
| Hypnotic medication use ≥5 times/week, n (%) | 15 (5.6) | 19 (5.2) | 36 (5.6) | 41 (7.6) | 17 (7.5) | 0.450 |
| CES-D ≥ 16, n (%) | 51 (19.1) | 71 (19.4) | 79 (12.2) | 68 (12.6) | 34 (14.9) | 0.004 |
| BMI, mean kg/m2 ± SD (N = 2048) | 29.9 ± 5.8 | 29.5 ± 5.7 | 28.8 ± 5.6 | 28.1 ± 5.4 | 28.2 ± 5.4 | <0.001 |
| Waist circumference, mean cm ± SD (N = 2046) | 102.8 ± 14.6 | 101.2 ± 14.7 | 99.7 ± 14.7 | 97.3 ± 13.9 | 99.0 ± 14.6 | <0.001 |
| Sleep duration, mean hours ± SD | 4.0 ± 0.9 | 5.6 ± 0.3 | 6.5 ± 0.3 | 7.4 ± 0.3 | 8.5 ± 0.5 | <0.001 |
| Sleep duration variability, mean ± SD | 94.0 ± 36.9 | 87.1 ± 38.5 | 74.0 ± 37.4 | 65.2 ± 35.8 | 65.4 ± 32.4 | <0.001 |
| Sleep maintenance efficiency, median % ± IQR | 91.2 ± 5.2 | 91.3 ± 4.6 | 91.7 ± 4.2 | 92.6 ± 3.9 | 92.9 ± 3.1 | <0.001 |
| Apnea–hypopnea index, median ± IQR (N = 1881) | 14.8 ± 26.2 | 9.5 ± 15.8 | 7.8 ± 15.8 | 7.5 ± 15.9 | 8.3 ± 15.6 | <0.001 |
| Obstructive sleep apnea, n(%) (N = 1881) | <0.001 | |||||
| None | 46 (18.6) | 110 (32.9) | 230 (38.1) | 186 (37.4) | 68 (34.3) | |
| Mild | 81 (32.8) | 113 (33.8) | 176 (29.1) | 155 (31.1) | 67 (33.8) | |
| Moderate | 52 (21.1) | 69 (20.7) | 117 (19.4) | 87 (17.5) | 34 (17.2) | |
| Severe | 68 (27.5) | 42 (12.6) | 81 (13.4) | 70 (14.1) | 29 (14.7) | |
| Nocturnal hypoxemia†, median % ± IQR (N=1881) | 1.8 ± 6.9 | 0.7 ± 3.7 | 0.6 ± 2.8 | 0.5 ± 2.7 | 0.6 ± 3.4 | <0.001 |
| HbA1c, mean ± SD | 6.2 ± 1.1 | 6.0 ± 0.8 | 6.0 ± 0.9 | 5.9 ± 0.8 | 5.9 ± 0.8 | <0.001 |
CES-D = Center for Epidemiologic Studies Depression Scale; IQR = interquartile range.
*p-Value tests for trend across sleep variability categories using one-way ANOVA or tests for a difference using Kruskal–Wallis or chi-square tests, as appropriate.
†Percent of sleep time with oxyhemoglobin saturation <90%.