Table 1.
Baseline Characteristics of the Sleep Heart Health Study Cohort by AHI
| AHI (Events/h) |
||||
|---|---|---|---|---|
| <5 (n = 3,461) | 5–14.9 (n = 1,831) | 15–19.9 (n = 749) | ≥30 (n = 400) | |
| Age, yr | 61.3 (11.1) | 64.8 (10.6) | 65.0 (10.4) | 64.3 (10.7) |
| FEV1, L | 2.63 (0.81) | 2.65 (0.84) | 2.71 (0.77) | 2.75 (0.75) |
| FVC, L | 3.51 (1.05) | 3.51 (1.08) | 3.57 (1.00) | 3.58 (0.98) |
| FEV1/FVC, % | 75.0 (8.1) | 75.7 (7.4) | 76.2 (7.7) | 76.8 (7.1) |
| BMI, kg/m2 | 27.0 (4.5) | 29.6 (5.4) | 30.8 (5.9) | 32.5 (6.1) |
| Sex, n (%) | ||||
| Women | 2,182 (63) | 835 (46) | 271 (36) | 117 (29) |
| Men | 1,279 (37) | 996 (54) | 478 (64) | 283 (71) |
| Race, n (%) | ||||
| White | 2,681 (77) | 1,400 (76) | 561 (75) | 296 (74) |
| African American | 288 (8) | 131 (7) | 63 (8) | 37 (9) |
| Native American | 269 (8) | 205 (11) | 91 (12) | 48 (12) |
| Hispanic | 167 (5) | 68 (4) | 30 (4) | 15 (4) |
| Other | 56 (2) | 27 (1) | 4 (1) | 4 (1) |
| Smoking status, n (%) | ||||
| Never | 1,641 (48) | 790 (43) | 331 (45) | 168 (42) |
| Former | 1,321 (38) | 873 (48) | 340 (46) | 203 (51) |
| Current | 474 (145) | 159 (9) | 72 (10) | 25 (6) |
| Hypertension, n (%) | 1,611 (47) | 1,061 (58) | 447 (60) | 268 (68) |
| Cardiovascular disease, n (%)* | 422 (13) | 350 (20) | 162 (23) | 91 (24) |
| Deaths, n (%) | 691 (20) | 468 (26) | 233 (31) | 117 (29) |
| Follow-up time, person-years | 38,338.7 | 19,554.6 | 7,830.5 | 4,164.0 |
| Mortality rate, per 1,000 person-years | 18.0 | 23.9 | 29.8 | 28.1 |
Definition of abbreviations: AHI = apnea–hypopnea index; BMI = body mass index.
P < 0.0001 for comparisons of age, FEV1/FVC, BMI, sex, race, smoking status, hypertension, diabetes, cardiovascular disease across AHI categories using chi-square and analysis of variance to compare categorical and continuous variables, respectively. P = 0.01 for comparison of FEV1 across categories. Values represent mean (SD) unless otherwise indicated.
*
Cardiovascular disease defined as presence of angina, heart failure, myocardial infarction, stroke, or any coronary revascularization procedure.