Table 1 Baseline characteristics of participants in the Shahrekord cohort study (n = 9,151)

Demographic variables

 Age, year

50 ± 9

49 ± 9

 < 0.001

Sex

 < 0.001

 Male

479 (36.3)

3732 (47.7)

 Female

841 (63.7)

4099 (52.3)

Ethnicity

 < 0.001

 Fars

624 (47.3)

3043 (38.9)

 Turk

108 (8.2)

512 (6.5)

 Lur Bakhtiari

521 (39.5)

3966 (50.6)

 Others

67 (5.1)

310 (4)

Education

 < 0.001

 Illiterate

403 (30.5)

2560 (32.7)

  < Diploma degree

529 (40.1)

3422 (43.7)

  ≥ Diploma degree

380 (28.9)

1789 (22.8)

Marital status

 < 0.001

 Single

12 (0.9)

143 (1.8)

 Married

1253 (94.9)

7343 (93.8)

 Divorced

49 (3.7)

285 (3.6)

 Widowed

6 (0.5)

60 (0.8)

^a Socioeconomic status

 < 0.001

 Low

330 (25)

2664 (34)

 Medium

459 (34.8)

2616 (33.4)

 High

519 (39.3)

2467 (31.5)

Anthropometric characteristics and metabolic parameters

 Weight, Kg

78.6 ± 13.4

72.3 ± 13.1

 < 0.001

 BMI, Kg/m2

29.9 ± 4.4

27.1 ± 4.5

 < 0.001

 Waist circumference, cm

99.4 ± 10.5

93.7 ± 11.3

 < 0.001

 Hip circumference, cm

103.9 ± 8.1

100.5 ± 7.7

 < 0.001

 Wrist circumference, cm

17.6 ± 1.5

17.3 ± 1.4

 < 0.001

 Total cholesterol, mg/dL

191 ± 40

184 ± 41

 < 0.001

 HDL cholesterol, mg/dL

51.1 ± 11.4

50.7 ± 11.6

0.31

 LDL cholesterol, mg/dL

105 ± 33

104 ± 33

0.44

 TG, mg/dL

174 ± 97

145 ± 85

 < 0.001

 Fasting glucose, mg/dL

102 ± 31

95 ± 25

 < 0.001

 AST, IU/L

21 ± 10

19 ± 8

 < 0.001

 ALT, IU/L

26 ± 17

21 ± 13

 < 0.001

 SBP, mmHg

117.6 ± 16.2

114.4 ± 17.2

 < 0.001

 DBP, mmHg

77.3 ± 10.5

74.9 ± 10.5

 < 0.001

Life style variables

 Physical Activity, METs

39.2 ± 6.4

41.4 ± 8.9

 < 0.001

 Smoking (yes)

158 (12)

1232 (15.7)

 < 0.001

 Alcohol Consumption (yes)

196 (14.8)

1263 (16.1)

0.13

 Using drug (yes)

151 (11.4)

1269 (16.2)

 < 0.001

Medical history and NAFLD severity assessments

 T2D (yes)

235 (28.8)

582 (13.4)

 < 0.001

 Hypertension (yes)

323 (24.5)

1047 (13.4)

 < 0.001

 MetS (yes)

436 (33)

1487 (19)

 < 0.001

 FLI

64.9 ± 23.2

46.9 ± 27.6

 < 0.001

 HSI

43.7 ± 13.1

36.9 ± 9.0

 < 0.001

Sleeping characteristics

 Sleeping time duration, hour

6.8 ± 1.5

6.9 ± 1.6

0.08

Sleeping time duration category, hour

0.11

  ≤ 7

825 (62.5)

4669 (59.6)

 7–9

379 (28.7)

2373 (30.3)

  ≥ 9

116 (8.8)

788 (10.1)

 Bedtime duration, hour

7.3 ± 1.5

7.3 ± 1.5

0.94

Bed time, hour,

 < 0.001

  ≤ 10 p.m

263 (19.9)

2046 (26.1)

 10 p.m.-12 a.m

559 (42.3)

3260 (41.6)

  ≥ 12 a.m

498 (37.7)

2524 (32.2)

Wake up time, hour

0.003

  ≤ 6 a.m

617 (46.7)

4035 (51.5)

 6–9 a.m

612 (46.4)

3363 (42.9)

  ≥ 9 a.m

91 (6.9)

433 (5.5)

Daytime nap (yes)

796 (60.3)

4206 (53.7)

 < 0.001

Daytime nap, hour

0.95 ± 0.6

0.96 ± 0.6

0.96

Sleep Efficiency (%)

92.3 ± 16.3

95.0 ± 34.3

 < 0.001

Falling asleep unintentionally (yes)

285 (21.6)

1508 (19.3)

0.05

Using sleeping pills (yes)

117 (8.9)

374 (4.8)

 < 0.001

Restless legs syndrome (yes)

195 (14.8)

916 (11.7)

0.002