Table 4.
HRs and 95% CIs for WASO Quartiles (Quartile I: <29.5 Minutes; Quartile II: 29.5–47.0 Minutes; Quartile III: 47.1–78.0 Minutes; and Quartile IV: >78.0 Minutes) Associated With Primary (MACE) and Secondary Composite Cardiovascular End Points
| Variable | Individuals, N | Person‐Years | Events, n (%) | Morbidity Rate* | Univariate Models | Multivariable Adjusted † | ||
|---|---|---|---|---|---|---|---|---|
| HR (95% CI) | P Value | HR (95% CI) | P Value | |||||
| Primary composite cardiovascular end point | ||||||||
| WASO, min | ||||||||
| Fourth quartile | 958 | 9379.5 | 172 (18.0) | 18.3 | 2.574 (1.960–3.381) | <0.001 | 1.436 (1.066–1.934) | 0.017 |
| Third quartile | 957 | 10094.8 | 118 (12.3) | 11.7 | 1.634 (1.222–2.185) | 0.001 | 1.169 (0.863–1.584) | 0.313 |
| Second quartile | 951 | 10224.0 | 110 (11.6) | 10.8 | 1.509 (1.124–2.026) | 0.006 | 1.334 (0.987–1.803) | 0.061 |
| First quartile | 944 | 10403.4 | 74 (7.8) | 7.1 | 1 (Reference) | 1 (Reference) | ||
| Continuous (per 1 min) | 1.007 (1.006–1.009) | <0.001 | 1.003 (1.001–1.005) | 0.012 | ||||
| Secondary composite cardiovascular end point | ||||||||
| WASO, min | ||||||||
| Fourth quartile | 958 | 8688.6 | 293 (30.6) | 33.7 | 2.378 (1.947–2.905) | <0.001 | 1.374 (1.103–1.712) | 0.005 |
| Third quartile | 957 | 9514.6 | 217 (22.7) | 22.8 | 1.606 (1.300–1.984) | <0.001 | 1.166 (0.935–1.455) | 0.173 |
| Second quartile | 951 | 9839.5 | 186 (19.6) | 18.9 | 1.334 (1.073–1.659) | 0.010 | 1.178 (0.943–1.473) | 0.149 |
| First quartile | 944 | 10087.6 | 143 (15.1) | 14.2 | 1 (Reference) | 1 (Reference) | ||
| Continuous (per 1 min) | 1.007 (1.006–1.009) | <0.001 | 1.003 (1.001–1.004) | 0.001 | ||||
| CVD mortality | ||||||||
| WASO, min | ||||||||
| Fourth quartile | 958 | 9852.3 | 88 (9.2) | 8.9 | 4.227 (2.671–6.691) | <0.001 | 2.240 (1.377–3.642) | 0.001 |
| Third quartile | 957 | 10479.5 | 49 (5.1) | 4.7 | 2.167 (1.320–3.556) | 0.002 | 1.447 (0.871–2.404) | 0.153 |
| Second quartile | 951 | 10645.0 | 39 (4.1) | 3.7 | 1.698 (1.014–2.842) | 0.044 | 1.431 (0.851–2.406) | 0.176 |
| First quartile | 944 | 10663.6 | 23 (2.4) | 2.2 | 1 (Reference) | 1 (Reference) | ||
| Continuous (per 1 min) | 1.009 (1.007–1.012) | <0.001 | 1.005 (1.002–1.008) | 0.002 | ||||
HR indicates hazard ratio; MACE, major adverse cardiovascular event; and WASO, wake after sleep onset.
*
Crude event rate per 1000 person‐years.
†
Adjusted by age, sex, race, smoking status, body mass index, prevalent hypertension and diabetes mellitus, apnea‐hypopnea index, and sleep duration.