Table 1 Baseline characteristics of the study population

Age (years)

45.88 (± 0.52)

45.23 (± 0.53)

46.55 (± 0.82)

0.034

BMI (kg/m2)

24.26 (± 0.10)

24.87 (± 0.13)

23.64 (± 0.12)

< 0.001

Education, n (%)

None

106 (3.10)

16 (1.04)

90 (4.76)

0.708

≤ High school

2056 (60.06)

878 (57.27)

1178 (62.33)

≥ College

1261 (36.84)

639 (41.68)

622 (32.91)

Marital status, n (%)

Single

408 (11.92)

235 (15.33)

173 (9.15)

< 0.001

Married, cohabited

2653 (77.51)

1218 (79.45)

1435 (75.93)

Other (divorce, separation)

362 (10.58)

80 (5.22)

282 (14.92)

Household income (US dollars), n (%)

< 871

610 (17.82)

245 (15.98)

365 (19.31)

0.012

871–2614

1366 (39.91)

639 (41.68)

727 (48.47)

2614–4357

876 (25.59)

395 (25.77)

481 (25.45)

≥ 4357

556 (16.24)

249 (16.24)

307 (16.24)

Unknown

15 (0.44)

5 (0.33)

10 (0.53)

Smoking, n (%)

Never

2166 (63.28)

372 (24.27)

1794 (94.92)

< 0.001

Former

689 (20.13)

649 (42.33)

40 (2.12)

Current

568 (16.59)

512 (33.40)

56 (2.96)

Alcohol, n (%)

Never drinker

658 (19.22)

127 (8.28)

531 (28.10)

< 0.001

Drinker

2765 (80.78)

1406 (91.72)

1359 (71.90)

Exercise, n (%)

No

901 (26.32)

801 (52.25)

1100 (58.20)

0.002

Low intensity

266 (7.77)

122 (7.96)

144 (7.62)

Moderate intensity

1266 (36.99)

610 (39.79)

646 (34.18)

Urinary metabolites (µg/g⋅creatinine)

ttMA

163.11 (± 7.38)

148.83 (± 5.62)

177.86 (± 12.70)

0.025

BMA

12.31 (± 3.44)

7.26 (± 0.47)

17.53 (± 6.88)

0.136

Blood lipid levels

TC (mg/dL)

186.10 (± 0.87)

185.87 (± 1.49)

186.33 (± 0.99)

0.804

TG (mg/dL)

170.27 (± 3.35)

198.55 (± 4.98)

141.06 (± 2.76)

< 0.001

HDL-C (mg/dL)

56.14 (± 0.43)

51.57 (± 0.50)

60.86 (± 0.52)

< 0.001

^aLDL-C (mg/dL)

98.12 (± 0.83)

98.31 (± 1.47)

97.93 (± 0.88)

0.830

TG/HDL-C ratio

3.51 (± 0.09)

4.33 (± 0.13)

2.66 (± 0.07)

< 0.001

^aLDL-C/HDL-C ratio

1.83 (± 0.02)

1.97 (± 0.04)

1.70 (± 0.02)

< 0.001

The continuous variables are presented as mean ± (standard deviation), and the categorical variables are presented as n (%).

Urinary metabolites levels were presented after creatinine adjustment.

^aLDL was calculated by the Friedewald formula after excluding persons with TG > 400 (mg/dL).

BMI, body mass index; ttMA, trans,trans-muconic acid; BMA, benzylmercapturic acid; TC, total cholesterol; TG, triglyceride; HDL-C, high-density lipoprotein; LDL-C, low-density lipoprotein