Table 1 Basic characteristics of the participants according to the quintiles of energy-adjusted selenium intake

n

3026

605

605

605

606

605

-

Sex, n (%)

 Male

 Female

1716 (56.7)

1310 (43.3)

317 (52.4)

288 (47.6)

296 (48.9)

309 (51.1)

306 (50.6)

299 (49.4)

360 (59.4)

246 (40.6)

437 (72.2)

168 (27.8)

< 0.001

Education, n (%)

 Illiterate

 Elementary school

 Middle and high school

  College

737 (24.4)

929 (30.7)

1043 (34.5)

317 (10.5)

155 (25.6)

207 (34.2)

201 (33.2)

42 (6.9)

156 (25.8)

193 (31.9)

194 (32.1)

62 (10.2)

128 (21.2)

198 (32.7)

197 (32.6)

82 (13.6)

171 (28.2)

164 (27.1)

211 (34.8)

60 (9.9)

127 (21.0)

167 (27.6)

240 (39.7)

71 (11.7)

< 0.001

Ethnicity, n (%)

 Persian

 Turk Nomad

 Others or mixed

2290 (75.7)

621 (20.5)

115 (3.8)

478 (79.0)

100 (16.5)

27 (4.5)

470 (77.7)

109 (18.0)

26 (4.3)

482 (79.7)

104 (17.2)

19 (3.1)

441 (72.8)

136 (22.4)

29 (4.8)

419 (69.3)

172 (28.4)

14 (2.3)

< 0.001

Smoking, n (%)

 Non-smoker

 Ex-smoker

 Current smoker

2212 (73.1)

220 (7.3)

594 (19.6)

427 (70.6)

46 (7.6)

132 (21.8)

467 (77.2)

27 (4.5)

111 (18.3)

468 (77.4)

42 (6.9)

95 (15.7)

440 (72.6)

46 (7.6)

120 (19.8)

410 (67.8)

59 (9.8)

136 (22.5)

< 0.001

Alcohol intake, n (%)

 No

 Yes

2684 (88.7)

342 (11.3)

531 (87.8)

74 (12.2)

550 (90.9)

55 (9.1)

558 (92.2)

47 (7.8)

534 (88.1)

72 (11.9)

511 (84.5)

94 (15.5)

< 0.001

Wealth score index, n (%)

 1st quintile

 2nd quintile

 3rd quintile

 4th quintile

 5th quintile

614 (20.3)

618 (20.4)

620 (20.5)

661 (21.8)

513 (17.0)

106 (17.5)

120 (19.8)

115 (19.0)

153 (25.3)

111 (18.3)

111 (18.3)

124 (20.5)

135 (22.3)

119 (19.7)

116 (19.2)

106 (17.5)

114 (18.8)

117 (19.3)

142 (23.5)

126 (20.8)

125 (20.6)

128 (21.1)

135 (22.3)

129 (21.3)

89 (14.7)

166 (27.4)

132 (21.8)

118 (19.5)

118 (19.5)

71 (11.7)

< 0.001

Age (years), mean ± SD

46.00 ± 8.17

47.08 ± 8.24

46.23 ± 8.10

45.89 ± 8.15

46.15 ± 8.46

44.66 ± 7.72

< 0.001

BMI (kg/m²), mean ± SD

26.67 ± 4.68

26.73 ± 4.96

26.55 ± 4.98

26.76 ± 4.46

26.67 ± 4.49

26.64 ± 4.50

0.947

Waist circumference (cm), mean ± SD

93.92 ± 10.60

94.29 ± 11.21

93.88 ± 10.98

94.14 ± 10.43

93.76 ± 10.17

93.53 ± 10.22

0.744

Serum TC (mg/dl), mean ± SD

174.81 ± 36.00

176.68 ± 34.27

173.40 ± 36.00

176.79 ± 35.41

175.07 ± 35.98

172.08 ± 38.08

0.095

Serum HDL-C (mg/dl), mean ± SD

41.73 ± 9.17

42.33 ± 9.33

43.04 ± 9.23

41.72 ± 9.43

41.49 ± 9.11

40.07 ± 8.49

< 0.001

Serum LDL-C (mg/dl), mean ± SD

103.77 ± 29.56

106.34 ± 27.95

102.53 ± 30.07

106.06 ± 28.69

104.26 ± 29.80

99.64 ± 30.78

< 0.001

Serum TG (mg/dl), median (range)

123.00 (1408)

119.00 (652)

126.00 (900)

126.00 (889)

126.00 (709)

133.00 (1408)

0.004

FPG (mg/dl), median (range)

93.00 (281)

93.00 (279)

92.00 (146)

93.00 (214)

93.00 (127)

93.00 (272)

0.863

ALT (U/L), median (range)

17.00 (218)

16.00 (95)

16.00 (180)

17.00 (204)

18.00 (157)

19.00 (215)

< 0.001

AST (U/L), median (range)

17.00 (396)

17.00 (57)

16.00 (395)

17.00 (77)

17.00 (122)

18.00 (174)

< 0.001

GGT (U/L), median (range)

19.00 (370)

19.00 (153)

18.00 (143)

18.00 (257)

20.00 (161)

21.00 (367)

< 0.001

SBP (mmHg), mean ± SD

114.69 ± 13.24

114.00 ± 13.19

113.64 ± 13.77

114.60 ± 13.51

115.24 ± 13.11

115.98 ± 12.51

0.015

DBP (mmHg), mean ± SD

75.48 ± 9.45

74.51 ± 9.42

74.78 ± 9.73

75.45 ± 9.46

75.79 ± 9.38

76.87 ± 9.11

< 0.001

Activity level (MET-h/week), mean ± SD

41.94 ± 6.91

41.67 ± 6.70

41.72 ± 6.33

41.92 ± 6.61

41.51 ± 6.59

42.86 ± 8.12

0.006

Dietary total energy intake (kcal/d), mean ± SD

2247.02 ± 607.57

2414.00 ± 673.77

2134.43 ± 549.51

2127.85 ± 559.15

2154.81 ± 572.45

2404.19 ± 603.20

< 0.001

Dietary SFA intake (g/day), mean ± SD

19.03 ± 7.66

21.78 ± 9.21

18.84 ± 7.34

17.84 ± 6.78

17.82 ± 6.77

18.86 ± 7.25

< 0.001

Dietary cholesterol intake (mg/day), mean ± SD

234.30 ± 112.60

218.59 ± 97.56

213.19 ± 94.16

255.97 ± 104.93

236.49 ± 109.53

277.27 ± 139.53

< 0.001

Dietary fiber intake (g/day), mean ± SD

26.85 ± 9.58

30.12 ± 11.56

26.02 ± 9.04

25.58 ± 9.00

24.98 ± 8.39

27.56 ± 8.71

< 0.001

Dietary fructose intake (g/day), mean ± SD

30.34 ± 16.90

41.30 ± 22.15

31.34 ± 14.57

28.43 ± 14.23

25.66 ± 13.50

24.99 ± 12.94

< 0.001

Dietary selenium intake (µg/day), mean ± SD

109.29 ± 37.03

88.77 ± 30.49

93.73 ± 27.36

102.91 ± 27.91

114.48 ± 28.79

146.58 ± 38.13

< 0.001

Dietary selenium intake (µg/kg/day), mean ± SD

1.57 ± 0.55

1.29 ± 0.47

1.37 ± 0.42

1.49 ± 0.43

1.64 ± 0.46

2.04 ± 0.61

< 0.001

NAFLD based on FLI, n (%)

1708 (56.4)

336 (55.5)

323 (53.4)

347 (57.4)

350 (57.8)

352 (58.2)

0.424

NAFLD based on HSI, n (%)

1570 (51.9)

309 (51.1)

297 (49.1)

318 (52.6)

323 (53.3)

323 (53.4)

0.526