Table 1 The characteristics of participants

Age (years)

27.4 ± 4.5

27.3 ± 4.6

0.401

Race/Ethnicity (%)

0.676

 Non-Hispanic White

58.6

58.2

 Non-Hispanic Black

11.7

12.5

 Mexican American

11.6

10.5

 Other race/ethnicity

18.0

18.8

Education level (%)

< 0.001

 Less than high school

11.7

8.3

 High school

25.8

20.0

 More than high school

62.5

71.7

Income to poverty ratio

2.7 ± 1.6

2.5 ± 1.6

0.003

Moderate recreational activities (%)

< 0.001

 Yes

47.4

53.4

 No

52.6

46.6

Smoked > = 100 cigarettes in life (%)

< 0.001

 Yes

43.0

28.6

 No

57.0

71.4

Body mass index (kg/m²)

27.9 ± 6.2

28.3 ± 7.7

0.043

Serum albumin (g/L)

45.1 ± 3.0

42.2 ± 3.2

< 0.001

Blood urea nitrogen (mmol/L)

4.7 ± 1.4

3.9 ± 1.2

< 0.001

Serum uric acid (μmol/L)

359.0 ± 71.9

272.0 ± 61.2

< 0.001

Serum phosphorus (mmol/L)

1.2 ± 0.2

1.2 ± 0.2

0.267

Serum calcium (mmol/L)

2.4 ± 0.1

2.3 ± 0.1

< 0.001

Blood lead (μmol/L)

0.05 ± 0.07

0.03 ± 0.03

< 0.001

Blood cadmium (μmol/L)

3.23 ± 4.12

3.56 ± 4.78

0.038

Lumbar bone mineral density (mg/cm²)

1041.0 ± 145.5

1056.7 ± 127.3

0.001