Table 1 Comparison of baseline characteristics according to NAFLD

Age, year

33 ± 8

37 ± 11

Male, n(%)

2053 (63.7%)

86 (61.4%)

BMI, kg/m²

22.3 ± 3.3

21.9 ± 3.2

High school above, n(%)

2632 (81.7%)

109 (77.9%)

Annual family personal income (thousand yuan)

 < 20

317 (9.8%)

15 (10.7%)

 20–40

236 (7.3%)

12 (8.6%)

 40–60

298 (9.2%)

16 (11.4%)

 60–80

473 (14.7%)

16 (11.4%)

Physical activity ≥ 1 time/week, n (%)

1230 (38.2%)

65 (46.4%)

Sleeping pills using

193 (6.0)

16 (11.4%)

Nocturnal sleeping duration/h, n(%)

 ≤ 7 h

2154 (66.8%)

103 (73.6%)

 > 7 h

1069 (33.2%)

37 (26.4%)

Daytime dapping duration/min, n(%)

 0

391 (12.1%)

9 (6.4%)

 < 30 min

346 (10.8%)

11 (7.9%)

 30-60 min

1653 (51.3%)

79 (56.4%)

 ≥ 60 min

833 (25.8%)

41 (29.3%)

Smoking, n(%)

 Never

2984 (92.6%)

126 (90.0%)

 Current

141 (4.4%)

11 (7.9%)

 Quitted

32 (1.0%)

2 (1.4%)

 Passive

66 (2.0%)

1 (0.7%)

Often staying up late

1751 (54.3%)

71 (50.7%)

Sedentary duration/(h per day)

 > 8

703 (21.8%)

36 (25.7%)

Coronary disease, n (%)

22 (0.7%)

0

Diabetes, n (%)

7 (0.2%)

0

Hypertension, n (%)

64 (2.0%)

8 (5.7%)

LDL-C

3.1 (0.7)

3.2 (0.6)

Triglycerides

1.2 (0.9)

1.2 (0.9)

HDL-C

1.3 (0.2)

1.4 (0.3)

Total cholesterol

4.8 (0.9)

5.0 (0.8)