Table 3 Characteristics of the study subjects

Socio-demographic characteristics

Age (year)

52, 44

49, 44

61, 56

< 0.001^b

40–49 (n, %)

1850 (44.1)

1768 (52.1)

82 (10.2)

50–59 (n, %)

1118 (26.6)

872 (25.7)

246 (30.5)

60–69 (n, %)

1231 (29.3)

753 (22.2)

478 (59.3)

Education (n, %)

< 0.001

≤ Elementary

1928 (45.9)

1338 (39.4)

590 (73.2)

Middle school

974 (23.2)

866 (25.5)

108 (13.4)

High school

1053 (25.1)

956 (28.2)

97 (12.0)

≥ College

244 (5.8)

233 (6.9)

11 (1.4)

Income level

(million KRW/month)

< 0.001

< 2

2960 (70.5)

2273 (67.0)

687 (85.2)

2–3.99

1000 (23.8)

905 (26.7)

95 (11.8)

≥ 4

239 (5.7)

215 (6.3)

24 (3.0)

Anthropometric parameters

Height (cm)

153.8 ± 0.1

154.3 ± 0.1

151.6 ± 0.2

< 0.001^a

Weight (kg)

58.9 ± 0.1

58.8 ± 0.1

59.3 ± 0.3

0.435 ^a

BMI (kg/m²)

24.9 ± 0.0

24.7 ± 0.1

25.8 ± 0.1

< 0.001 ^a

Waist circumference (cm)

81.7 ± 0.1

80.8 ± 0.2

85.7 ± 0.3

< 0.001 ^a

Hip circumference (cm)

93.6 ± 0.1

93.5 ± 0.1

93.9 ± 0.2

0.201 ^a

Body fat (%)

31.9, 28.4

31.6, 28.1

33.4, 30.1

< 0.001^b

Muscle mass (kg)

37.7 ± 0.1

37.9 ± 0.1

37.0 ± 0.2

< 0.001 ^a

Blood pressure (mmHg)

SBP

122, 110

120, 108

130, 120

< 0.001^b

DBP

80, 72

80, 72

84, 78

< 0.001^b

Lifestyle factors

Alcohol intake

status (n, %)

< 0.001

Current

1058 (25.2)

909 (26.8)

149 (18.5)

Former

129 (3.1)

105 (3.1)

24 (3.0)

Never

3012 (71.7)

2379 (70.1)

633 (78.5)

Alcohol intake

(g/day)

0.0, 0.0

0.0, 0.0

0.0, 0.0

< 0.001^b

Smoking status

(n, %)

0.155

Current

143 (3.4)

117 (3.4)

26 (3.3)

Former

56 (1.3)

39 (1.1)

17 (2.1)

Never smoked

4000 (95.3)

3237 (95.4)

763 (94.7)

Average sleep

time (hours)

7, 6

7, 6

7, 6

0.003^b

< 7 (n, %)

1880 (44.8)

1553 (45.8)

327 (40.6)

7–9 (n, %)

2214 (52.7)

1768 (52.1)

446 (55.3)

> 9 (n, %)

105 (2.5)

72 (2.1)

33 (4.1)

Insomnia (n, %)

896 (21.3)

664 (19.6)

232 (28.8)

< 0.001

Sleep hardness

(n, %)

709 (16.9)

520 (15.3)

189 (23.4)

< 0.001

Physical activity

(≥ 30 min/day)

High-intensity

1357 (32.3)

1033 (30.4)

324 (40.2)

< 0.001

Moderate-intensity

1411 (33.6)

1176 (34.7)

235 (29.2)

0.052

Low-intensity

3856 (91.8)

3137 (92.5)

719 (89.2)

0.020

Sedentary

3703 (88.2)

3010 (88.7)

693 (86.0)

0.060

Stable

2142 (51.0)

1763 (52.0)

379 (47.0)

0.014

Coffee consumption (n, %)

< 0.001

0 cup/week

1198 (28.5)

902 (26.6)

296 (36.7)

< 1 cup/week

281 (6.7)

224 (6.6)

57 (7.1)

1–6 cup/week

712 (17.0)

584 (17.2)

128 (15.9)

1 cup/day

1230 (29.3)

1014 (29.9)

216 (26.8)

≥ 2 cup/day

778 (18.5)

669 (19.7)

109 (13.5)

Reproductive factors

Menopausal status (yes) (n, %)

2654 (63.2)

1911 (56.3)

743 (92.2)

< 0.001

Age at menopause (year)

47, 45

47, 45

48, 45

0.147^b

Age at menarche (year)

16, 15

16, 14

16, 15

< 0.001^b

Pregnancy experience

(yes) (n, %)

4157 (99.0)

3359 (99.0)

798 (99.0)

0.981

Breast cancer

surgery (n, %)

24 (0.6)

18 (0.5)

6 (0.7)

0.469

Nutrient intakes

Energy (Kcal/day)

1681.5, 1383.3

1692.3, 1395.1

1640.6, 1345.4

0.008^b

Carbohydrate (g/day)

301.9, 259.6

302.7, 260.1

298.9, 258.0

0.780^b

Protein (g/day)

55.6 ± 0.4

56.1 ± 0.4

53.3 ± 0.9

< 0.001^a

Fat (g/day)

28.9 ± 0.3

29.7 ± 0.3

25.6 ± 0.7

< 0.001^a

Fiber (g/day)

20.6 ± 0.2

20.6 ± 0.2

20.6 ± 0.4

0.244^a

Calcium (mg/day)

384.2, 266.0

392.5, 270.7

347.0, 243.1

< 0.001^b

Phosphorus (mg/day)

877.8, 661.5

887.4, 669.4

847.3, 623.3

0.002^b

Magnesium (mg/day)

106.0, 52.8

105.7, 53.9

108.5, 49.0

0.515^b

Sodium (mg/day)

2170.0 ± 20.3

2178.3 ± 22.5

2135.2 ± 47.6

0.024^a

Potassium (mg/day)

2637.8 ± 20.7

2637.9 ± 22.4

2637.7 ± 51.7

0.178^a

Iron (mg/day)

12.2 ± 0.1

12.2 ± 0.1

12.2 ± 0.2

0.365^a

Zinc (mg/day)

10.7, 8.4

10.8, 8.4

10.4, 8.2

0.074^b

Copper (µg/day)

598.3, 339.6

600.8, 341.3

587.0, 335.4

0.766^b

Selenium (µg/day)

35.7 ± 0.4

36.8 ± 0.4

31.0 ± 1.0

< 0.001^a

Manganese (mg/day)

2.1, 0.9

2.1, 0.9

2.2, 0.9

0.545^b

Cholesterol (mg/day)

127.2, 72.2

133.6, 77.4

98.1, 58.7

< 0.001^b

Retinol (µg/day)

64.6, 31.7

67.5, 34.6

48.5, 21.6

< 0.001^b

Beta-carotene (µg/day)

2423.6 ± 28.1

2459.1 ± 31.3

2274.0 ± 63.6

< 0.001^a

Vitamin D

(µg/day)

1.9, 0.9

2.1, 1.0

1.4, 0.6

< 0.001^b

Vitamin E

(mg/day)

9.9 ± 0.1

10.0 ± 0.1

9.5 ± 0.2

< 0.001^a

Vitamin K

(µg/day)

100.1, 59.6

102.0, 62.0

90.5, 50.4

< 0.001^b

Vitamin B6

(mg/day)

1.8 ± 0.0

1.8 ± 0.0

1.7 ± 0.0

< 0.001^a

Vitamin C

(mg/day)

142.9 ± 2.2

142.0 ± 2.3

146.8 ± 5.9

0.161^a

Diet quality indices

INQ

1.0, 0.8

1.0. 0.8

1.0, 0.8

0.280^b

KHEI

43.6 ± 0.2

44.1 ± 0.2

41.8 ± 0.4

< 0.001^a

DII

2.2, 1.7

2.2, 1.7

2.4, 1.8

< 0.001^b

NEAP

37.7 ± 0.2

38.0 ± 0.2

36.2 ± 0.4

< 0.001^a

PRAL

14.8, 7.1

15.3, 7.6

13.2, 5.0

< 0.001^b

aMED

4, 3

4, 3

4, 3

0.928^b

DASH

25, 22

25, 22

25, 23

0.014^b

Medical history

Hypertension (n, %)

759 (18.1)

537 (15.8)

222 (27.5)

< 0.001

Diabetes mellitus

(n, %)

263 (6.3)

198 (5.8)

65 (8.1)

0.019

Allergic diseases

(n, %)

275 (6.5)

236 (7.0)

39 (4.8)

0.029

Myocardial infarction (n, %)

30 (0.7)

24 (0.7)

6 (0.7)

0.911

Thyroid disease

(n, %)

209 (5.0)

170 (5.0)

39 (4.8)

0.840

Congestive heart failure (n, %)

9 (0.2)

7 (0.2)

2 (0.2)

0.817

Coronary artery disease (n, %)

37 (0.9)

30 (0.9)

7 (0.9)

0.966

Hyperlipidemia (n, %)

88 (2.1)

70 (2.1)

18 (2.2)

0.762

Asthma (n, %)

112 (2.7)

89 (2.6)

23 (2.9)

0.715

COPD (n, %)

18 (0.4)

17 (0.5)

1 (0.1)

0.141

Kidney disease

(n, %)

147 (3.5)

119 (3.5)

28 (3.5)

0.963

Cerebrovascular disease (n, %)

46 (1.1)

34 (1.0)

12 (1.5)

0.233

Gout (n, %)

391 (9.3)

279 (8.2)

112 (13.9)

< 0.001

Arthritis (n, %)

937 (22.3)

661 (19.5)

276 (34.2)

< 0.001

Medication history

Steroids

14 (0.3)

13 (0.4)

1 (0.1)

0.251

Oral contraceptives

42 (1.0)

36 (1.1)

6 (0.7)

0.417

Insulin medication

38 (0.9)

30 (0.9)

8 (1.0)

0.770

Hypertension medication

593 (14.1)

411 (12.1)

182 (22.6)

< 0.001

Arthritis medication

268 (6.4)

190 (5.6)

78 (9.7)

< 0.001

Thyroid medication

110 (2.6)

88 (2.6)

22 (2.7)

0.828

Hormone replacement

therapy

184 (4.4)

168 (5.0)

16 (2.0)

< 0.001

Osteoporosis medication

144 (3.4)

99 (2.9)

45 (5.6)

< 0.001

Stroke medication

11 (0.3)

7 (0.2)

4 (0.5)

0.148

Asthma medication

48 (1.1)

40 (1.2)

8 (1.0)

0.655

Hyperlipidemia medication

27 (0.6)

20 (0.6)

7 (0.9)

0.373

Anticonvulsants

1 (0.0)

1 (0.0)

0 (0.0)

0.626

Anticoagulants

1 (0.0)

0 (0.0)

1 (0.1)

0.040

Family history

Osteoporosis

Parents

141 (3.4)

134 (3.9)

7 (0.9)

< 0.001

Siblings

23 (0.5)

17 (0.5)

6 (0.7)

0.400

Other

2 (0.0)

2 (0.1)

0 (0.0)

0.491

Biochemical parameters

Albumin (g/dL)

4.1, 4.0

4.1, 4.0

4.1, 4.0

0.025^b

Creatinine (mg/dL)

0.7, 0.7

0.7, 0.7

0.7, 0.7

0.180^b

AST (IU/L)

25.0, 22.0

25.0, 22.0

26.0, 22.0

< 0.001^b

ALT (IU/L)

19.0, 16.0

19.0, 16.0

21.0, 17.0

< 0.001^b

Total-C (mg/dL)

192.2 ± 0.6

190.1 ± 0.6

201.0 ± 1.3

< 0.001 ^a

HDL-C (mg/dL)

44.0, 39.0

45.0, 39.0

43.0, 37.0

< 0.001^b

Total protein

(g/dL)

7.2, 7.0

7.2, 7.0

7.2, 7.0

0.367^b

Calcium (mg/dL)

9.6, 9.3

9.6, 9.3

9.6, 9.3

0.125^b

Sodium (mmol/L)

143.0, 141.0

142.0, 141.0

143.0, 142.0

< 0.001^b

CRP (mg/dL)

0.1, 0.1

0.1, 0.1

0.2, 0.1

< 0.001^b

HbA1c (%)

5.6, 5.3

5.6, 5.3

5.7, 5.5

< 0.001^b

TG (mg/dL)

127.0, 95.0

123.0, 93.0

143.0, 108.0

< 0.001^b

WBC (10³/µL)

6.4 ± 0.0

6.4 ± 0.0

6.4 ± 0.1

0.349 ^a

Hematocrit (%)

38.1, 36.3

38.1, 36.1

38.5, 36.9

< 0.001^b

Hemoglobin (g/dL)

12.6, 12.0

12.6, 12.0

12.7, 12.2

< 0.001^b

BUN (mg/dL)

13.8 ± 0.1

13.5 ± 0.1

14.7 ± 0.2

< 0.001 ^a

Renin (ng/mL/hour)

2.2 ± 0.0

2.2 ± 0.0

2.2 ± 0.1

0.017 ^a

eGFR (mL/min/1.73m²)

202.7, 169.8

207.0, 174.6

194.3, 157.1

< 0.001^b

HOMA–IR

1.5, 1.1

1.5, 1.1

1.7, 1.2

< 0.001^b

Genetic factors

rs7529390

0.005

AA

58 (1.4)

41 (1.2)

17 (2.1)

AC

839 (20.0)

653 (19.2)

186 (23.1)

CC

3302 (78.6)

2699 (79.5)

603 (74.8)

rs628948

0.469

AA

1216 (29.0)

973 (28.7)

243 (30.1)

GA

2077 (49.5)

1676 (49.4)

401 (49.8)

GG

906 (21.6)

744 (21.9)

162 (20.1)

rs238340

0.005

GG

142 (3.4)

116 (3.4)

26 (3.2)

GT

1400 (33.3)

1092 (32.2)

308 (38.2)

TT

2657 (63.3)

2185 (64.4)

472 (58.6)

rs6752877

0.684

AA

3959 (94.3)

3194 (94.1)

765 (94.9)

CA

235 (5.6)

195 (5.7)

40 (5.0)

CC

5 (0.1)

4 (0.1)

1 (0.1)

rs2722298

< 0.001

CC

2706 (64.4)

2234 (65.8)

472 (58.6)

TC

1347 (32.1)

1042 (30.7)

305 (37.8)

TT

146 (3.5)

117 (3.4)

29 (3.6)

rs13182402

0.399

CC

15 (0.4)

12 (0.4)

3 (0.4)

CT

288 (6.9)

224 (6.6)

64 (7.9)

TT

3896 (92.8)

3157 (93.0)

739 (91.7)

rs16894980

0.335

AA

67 (1.6)

51 (1.5)

16 (2.0)

AG

908 (21.6)

746 (22.0)

162 (20.1)

GG

3224 (76.8)

2596 (76.5)

628 (77.9)

rs3212217

0.865

CC

1130 (26.9)

911 (26.8)

219 (27.2)

GC

2138 (50.9)

1724 (50.8)

414 (51.4)

GG

931 (22.2)

758 (22.3)

173 (21.5)

rs12100867

0.235

AA

2167 (51.6)

1768 (52.1)

399 (49.5)

GA

1707 (40.7)

1372 (40.4)

335 (41.6)

GG

325 (7.7)

253 (7.5)

72 (8.9)

rs12590815

0.203

AA

118 (2.8)

102 (3.0)

16 (2.0)

AG

1118 (26.6)

911 (26.8)

207 (25.7)

GG

2963 (70.6)

2380 (70.1)

583 (72.3)

rs746219

0.097

GG

1977 (47.1)

1619 (47.7)

358 (44.4)

TG

1790 (42.6)

1439 (42.4)

351 (43.5)

TT

432 (10.3)

335 (9.9)

97 (12.0)

rs6064822

0.916

AA

32 (0.8)

25 (0.7)

7 (0.9)

AG

644 (15.3)

522 (15.4)

122 (15.1)

GG

3523 (83.9)

2846 (83.9)

677 (84.0)

rs1555364

0.970

AA

3518 (83.8)

2841 (83.7)

677 (84.0)

GA

646 (15.4)

524 (15.4)

122 (15.1)

GG

35 (0.8)

28 (0.8)

7 (0.9)