Table 1.
Participant characteristics for the entire cohort and categorized by OSA severity
| All participants | No/mild OSA | Moderate OSA | Severe OSA | P-value | |
|---|---|---|---|---|---|
| N | 1295 | 552 | 322 | 421 | |
| Female (%) | 538 (41.5) | 282 (51.1) | 117 (36.3)* | 139 (33.0)* | <.001 |
| Age (years) | 54.0 ± 12.7 | 53.3 ± 13.4 | 55.4 ± 12.0 | 53.9 ± 12.3 | .060 |
| BMI (kg/m²) | 34.2 ± 8.3 | 30.7 ± 6.6 | 34.7 ± 8.1* | 38.2 ± 8.6* † | <.001 |
| White (%) | 1060 (81.9) | 464 (84.1) | 257 (79.8) | 339 (80.5) | .201 |
| OSA severity | |||||
| ODI (4%, events/h; TRT) | 17.7 (5.2−37.8) | 4.0 (1.5−9.6) | 20.8 (17.2−24.9)* | 50.3 (38.6−66.8)* † | <.001 |
| Mean Spo2 (%; TRT) | 91.1 (87.8−93.4) | 93.3 (91.6−94.7) | 90.8 (88.4−92.6)* | 87.2 (84.0−90.2)* † | <.001 |
| T90 (% TRT) | 19.6 (2.2−70.0) | 1.7 (0.2−14.8) | 20.9 (7.2−68.1)* | 68.3 (35.6−91.0)* † | <.001 |
| Daytime sleepiness and sleep quality | |||||
| ESS Score | 9.7 ± 5.2 (n=1276) | 9.1 ± 5.0 (n = 537) | 9.1 ± 5.2 (n = 320) | 10.8 ± 5.2* † (n = 419) | <.001 |
| ESS > 10 (%) | 629 (49.3) | 245 (45.6) | 145 (45.3) | 239 (57.0)* † | <.001 |
| PSQI Global Score | 8.8 ± 4.0 (n = 1242) | 8.6 ± 4.0 (n = 515) | 8.7 ± 4.1 (n = 311) | 9.0 ± 4.0 (n = 416) | .275 |
| PSQ I > 5 (%) | 1053 (84.8) | 430 (83.5) | 261 (83.9) | 362 (87.0) | .293 |
| Sleep duration (h) | 6.5 ± 1.5 (n = 1293) | 6.5 ± 1.4 (n = 551) | 6.5 ± 1.5 (n = 321) | 6.4 ± 1.7 (n = 421) | .193 |
| Sleep ≤ 6 h (%) | 609 (47.1) | 232 (42.1) | 150 (46.7) | 227 (53.9)* | .001 |
| ISI (total score) | 12.6 ± 5.8 (n = 1274) | 12.1 ± 5.7 (n = 536) | 12.6 ± 6.0 (n = 319) | 13.3 ± 5.8* (n = 419) | .006 |
| Insomnia (%) | 1006 (79.0) | 420 (78.4) | 249 (78.1) | 337 (80.4) | .664 |
| RLS (%) | 291 (22.7) | 128 (23.5) | 78 (24.5) | 85 (20.2) | .312 |
| RLS severity | 4.7 ± 1.6 | 4.6 ± 1.7 | 4.7 ± 1.8 | 5.0 ± 1.4 | .142 |
| Kidney function | |||||
| Serum creatinine (µmol/L) | 80.0 (69.0−91.0) | 76.0 (66.0−87.0) | 82.5 (71.0−92.3)* | 83.0 (71.0−96.0)* | <.001 |
| eGFR (mL/min/1.73 m²) | 87.0 (74.0−98.0) | 90.0 (77.0−100.0) | 87.0 (71.8−98.0)* | 84.0 (71.5−96.5)* | <.001 |
| Urine albumin (mg/L)# | 8.6 (5.0−21.4) | 8.0 (5.0−14.0) | 8.3 (5.0−26.0)* | 11.0 (5.0−31.6)* | <.001 |
| Urine creatinine (mmol/L) | 11.5 (6.7−16.6) | 11.4 (6.5−16.5) | 11.5 (7.0−16.4) | 11.6 (6.7−17.0) | .625 |
| ACR (mg/mmol) | 0.9 (0.5−2.0) | 0.8 (0.5−1.5) | 0.9 (0.5−2.3)* | 1.0 (0.5−2.9)* | <.001 |
| Comorbidities | |||||
| Kidney disease (%) | 102 (7.9) | 38 (6.9) | 24 (7.5) | 40 (9.5) | .307 |
| Proteinuria | 94 (7.3) | 33 (6.0) | 23 (7.1) | 38 (9.0) | .192 |
| Smoking | |||||
| Never smoker (%) | 636 (49.1) | 290 (52.5) | 153 (47.5) | 193 (45.8) | .153 |
| Past smoker (%) | 510 (39.4) | 210 (38.0) | 129 (40.1) | 171 (40.6) | |
| Current smoker (%) | 149 (11.5) | 52 (9.4) | 40 (12.4) | 57 (13.5) | |
| Hypertension (n, %) | 592 (45.7) | 200 (36.3) | 176 (54.7)* | 216 (51.3)* | <.001 |
| High cholesterol (%) | 510 (39.5) | 176 (32.1) | 156 (48.4)* | 178 (42.3)* | <.001 |
| Diabetes (%) | 239 (18.5) | 64 (11.7) | 60 (18.6)* | 115 (27.3)* | <.001 |
| Coronary artery disease (%) | 105 (8.1) | 32 (5.8) | 36 (11.2)* | 37 (8.8) | .016 |
| Heart failure (%) | 43 (3.3) | 17 (3.1) | 15 (4.7) | 11 (2.6) | .284 |
| Atrial fibrillation (%) | 88 (6.8) | 45 (8.2) | 18 (5.6) | 25 (5.9) | .232 |
| Past stroke (%) | 37 (2.9) | 13 (2.4) | 14 (4.4) | 10 (2.4) | .180 |
| COPD (%) | 71 (5.5) | 28 (5.1) | 16 (5.0) | 27 (6.4) | .595 |
| Asthma (%) | 275 (21.3) | 116 (21.1) | 62 (19.3) | 97 (23.1) | .444 |
| Medications | |||||
| NSAIDs (%) | 92 (7.1) | 37 (6.7) | 25 (7.8) | 30 (7.1) | .848 |
| Proton pump inhibitors (%) | 288 (22.3) | 120 (21.8) | 73 (22.7) | 95 (22.6) | .940 |
Number (%), categorical variables (p-value = χ2); mean ± SD or median (interquartile range), continuous variables (p-value = ANOVA or Kruskal−Wallis H).
#Urine albumin was below detectable limits in 275 participants and above detectable limits in two participants.
* p < .05 versus no/mild OSA.
† p < .05 versus moderate OSA.
Abbreviations: BMI, body mass index; ODI, oxygen desaturation index based upon 4% desaturations; mean SpO2, mean arterial oxyhemoglobin saturation; T90, percentage of total recording time (TRT) with SpO2 <90%; ESS, Epworth Sleepiness Scale; PSQI, Pittsburgh Sleep Quality Index; ISI, insomnia severity index; RLS, restless legs syndrome; eGFR, estimated glomerular filtration rate; ACR, urine albumin:creatinine ratio; COPD, chronic obstructive pulmonary disease; NSAID, non-steroidal anti-inflammatory drugs.