Table 1 Characteristics of subjects with and without subclinical hypothyroidism

Female, %

45.3

49.1

0.500

Age, years

40.6 ± 15.0

42.4 ± 15.8

0.297

Anthropometric variables

  BMI, kg/m²

22.6 ± 3.1

23.9 ± 3.2

< 0.001

  WC, cm

77.8 ± 10.6

81.7 ± 9.5

0.001

  SBP, mmHg

122.3 ± 16.2

127.0 ± 19.0

0.019

  DBP, mmHg

76.4 ± 10.8

80.0 ± 11.6

0.013

Laboratory measurements

  TSH, mIU/L

1.92 (1.42, 2.51)

5.01 (4.60,6.13)

< 0.001

  TPOAb +, %

8.8

19.5

0.006

  TgAb +, %

6.3

26.4

< 0.001

  UIC, µg/L

140.70 (89.28, 222.40)

152.20 (99.73,227.90)

0.275

  FBG, mmol/L

5.04 (4.69, 5.66)

5.17 (4.80, 5.50)

0.262

  HbA1c, %

5.8 ± 0.9

5.9 ± 1.0

0.472

  TG, mmol/L

0.98 (0.69, 1.37)

1.08 (0.81, 1.59)

0.102

  TC, mmol/L

4.88 ± 1.09

5.09 ± 1.19

0.087

  HDL-C, mmol/L

1.37 ± 0.40

1.35 ± 0.38

0.151

  LDL-C, mmol/L

2.44 ± 0.70

2.57 ± 0.79

0.712

  UA, mmol/L

340.35 ± 95.15

346.59 ± 92.61

0.554

Lifestyle information

  PSQI ≥ 7, %

15.1

25.8

0.018

  More than 30 min lunch break, %

44.7

52.8

0.145

  Stay up late on weekdays, %

54.7

23.9

< 0.001

  Stay up late on weekends, %

67.3

62.9

0.410

  Sleep duration on weekdays (< 5 h/5 ~ 6 h/7 ~ 8 h/9 ~ 10 h/>10 h), %

1.9/27.7/57.9/12.6/0

4.4/32.7/52.2/8.2/2.5

0.087

  Sleep duration on weekends (< 5 h/5 ~ 6 h/7 ~ 8 h/9 ~ 10 h/>10 h), %

1.3/15.1/59.1/24.5/0

1.9/20.8/61.6/11.9/3.8

0.003

  Exercise and intensity (no/low/medium or high), %

38.4/44.0/17.6

42.1/35.2/14.5

0.242

  Daily salt intake (< 5 g/5 ~ 10 g/>10 g), %

14.5/73/12.6

14.5/73/12.6

0.759

  Iodized salt intake, %

95.0

89.3

0.061

  Iodine-rich foods intake (none/monthly/daily), %

11.9/70.4/17.6

13.2/71.1/15.7

0.872

  Smoking, %

18.9

16.4

0.556