Table 1 Baseline characteristics of the study population

Age (year)

47.38 (0.31)

44.31 (0.60)

46.75 (0.46)

48.82 (0.42)

49.67 (0.41)

 < 0.0001

BMI (Kg/m^2)

28.72 (0.11)

25.55 (0.15)

27.75 (0.17)

29.91 (0.18)

31.72 (0.18)

 < 0.0001

HDL-C (mmol/L)

1.39 (0.01)

1.76 (0.01)

1.46 (0.01)

1.29 (0.01)

1.06 (0.01)

 < 0.0001

Triglyceride (mmol/L)

1.46 (0.02)

0.67 (0.01)

1.02 (0.01)

1.43 (0.01)

2.72 (0.05)

 < 0.0001

Waist circumference (cm)

98.69 (0.27)

89.45 (0.39)

96.11 (0.43)

101.97 (0.35)

107.36 (0.46)

 < 0.0001

VAI

2.09 (0.04)

0.63 (0.01)

1.17 (0.00)

1.89 (0.01)

4.70 (0.10)

 < 0.0001

Gender (%)

0.23

 Female

51.69 (0.02)

50.58 (1.20)

51.30 (1.16)

53.78 (1.06)

51.13 (1.24)

 Male

48.31 (0.02)

49.42 (1.20)

48.70 (1.16)

46.22 (1.06)

48.87 (1.24)

Races (%)

 < 0.0001

 Mexican American

8.72 (0.01)

6.08 (0.63)

8.19 (1.06)

10.24 (1.20)

10.41 (1.10)

 Non-Hispanic Black

10.25 (0.01)

16.46 (1.34)

10.80 (0.88)

8.67 (0.83)

5.00 (0.54)

 Non-Hispanic White

68.29 (0.04)

64.91 (1.96)

68.36 (1.95)

68.15 (1.87)

71.78 (2.01)

 Others

12.74 (0.01)

12.55 (1.24)

12.66 (1.02)

12.94 (0.89)

12.81 (1.27)

Educational levels (%)

 < 0.0001

 Less than 9th grade

6.05 (0.00)

4.07 (0.49)

5.43 (0.50)

6.78 (0.69)

7.95 (0.65)

 9-11th grade

12.13 (0.01)

9.27 (0.67)

11.21 (0.99)

12.89 (0.91)

15.20 (0.93)

 High school graduate

29.73 (0.01)

18.83 (1.10)

22.10 (1.26)

21.97 (1.22)

24.16 (1.44)

 Some college or AA degree

21.76 (0.01)

29.28 (1.23)

28.60 (1.14)

31.99 (1.49)

31.48 (1.40)

 College graduate or above

30.33 (0.01)

38.56 (1.67)

32.66 (1.66)

26.37 (1.57)

21.21 (1.36)

Physical activity (%)

 < 0.0001

 Very low PA

24.16 (0.01)

17.49 (1.03)

21.77 (1.04)

26.69 (1.22)

30.79 (1.40)

 Low PA

21.24 (0.01)

20.09 (0.91)

21.13 (1.03)

22.03 (1.24)

21.72 (1.23)

 Medium PA

12.50 (0.00)

13.10 (0.87)

13.92 (0.72)

11.76 (0.67)

11.20 (0.87)

 High PA

42.10 (0.02)

49.32 (1.34)

43.18 (1.01)

39.52 (1.29)

36.29 (1.41)

BMI (%)

 < 0.0001

 Normal weight

30.96 (0.01)

53.97 (1.24)

35.86 (1.53)

22.22 (1.21)

11.74 (0.87)

 Overweight

33.61 (0.01)

29.43 (1.06)

36.38 (1.37)

34.99 (1.31)

33.99 (1.13)

 Obesity

35.18 (0.01)

16.60 (0.84)

27.76 (1.26)

42.79 (1.24)

54.27 (1.29)

DM (%)

15.69 (0.01)

7.34 (0.61)

10.63 (0.81)

18.07 (1.06)

26.88 (1.15)

 < 0.0001

Hypertension (%)

37.22 (0.02)

24.57 (1.20)

34.10 (1.34)

39.67 (1.32)

50.69 (1.20)

 < 0.0001

Kidney stone (%)

9.24 (0.01)

6.08 (0.55)

8.57 (0.90)

9.95 (0.64)

12.40 (0.93)

 < 0.0001

Kidney stone recurrence (%)

2.97 (0.00)

1.78 (0.36)

1.86 (0.32)

3.78 (0.55)

4.51 (0.69)

 < 0.0001