Baseline characteristics of the participants according to snoring frequency (%)
| Never (n=23 208) | Occasionally (n=12 047) | Frequently (n=14 198) | |
| Men | 7923 (38.3) | 5179 (25.0) | 7589 (36.7) |
| Age (years, x±s) | 50.07±10.63 | 50.79±9.90 | 53.18±9.69 |
| Smoking status | |||
| Never | 15 872 (68.4) | 7179 (59.6) | 7035 (49.5) |
| Occasional | 890 (3.8) | 651 (5.4) | 804 (5.7) |
| Ex-regular | 919 (4.0) | 632 (5.2) | 1056 (7.4) |
| Current regular | 5527 (23.8) | 3585 (29.8) | 5303 (37.4) |
| Alcohol status | |||
| Never | 15 215 (65.6) | 6682 (55.5) | 7051 (49.7) |
| Occasional | 4415 (19.0) | 2957 (24.5) | 3420 (24.1) |
| Ex-regular | 378 (1.6) | 205 (1.7) | 364 (2.6) |
| Current regular | 3200 (13.8) | 2203 (18.3) | 3363 (23.7) |
| Educational attainment | |||
| No formal school | 7070 (30.5) | 3159 (26.2) | 4358 (30.7) |
| Primary school | 7336 (31.6) | 3687 (30.6) | 4965 (35.0) |
| Middle school | 6753 (29.1) | 3749 (31.1) | 3552 (25.0) |
| High school and above | 2049 (8.8) | 1452 (12.1) | 1323 (9.3) |
| Household income (¥) | |||
| <20 000 | 6230 (26.8) | 2755 (22.9) | 3947 (27.8) |
| 20 000–34 999 | 7705 (33.2) | 3838 (31.9) | 4217 (29.7) |
| ≥35 000 | 9273 (40/0) | 5454 (45.3) | 6034 (42.5) |
| WHR (x±s) | 0.87±0.06 | 0.89±0.07 | 0.91±0.07 |
| BMI (kg/m2, x±s) | 23.11±2.91 | 24.18±3.00 | 25.15±3.33 |
| BFP (%, x±s) | 27.59±7.61 | 28.69±7.91 | 29.27±8.55 |
| MET (x±s) | 26.34±15.14 | 25.87±14.64 | 25.72±15.42 |
| Married | 21 304 (91.8) | 11 359 (94.3) | 13 316 (93.8) |
| Hypertension (yes) | 1905 (8.2) | 1474 (12.2) | 2288 (16.1) |
| Family history of diabetes (yes) | 1207 (5.4) | 804 (6.9) | 980 (7.1) |
| Medications for sleep (yes) | 326 (1.4) | 158 (1.3) | 160 (1.1) |
BFP, body fat percentage; BMI, body mass index; MET, metabolic equivalent task; WHR, waist-hip ratio.