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Table 1 Characteristics of the study population overall and by NHANES cycle

From: Construction of environmental risk score beyond standard linear models using machine learning methods: application to metal mixtures, oxidative stress and cardiovascular disease in NHANES

 

Cycle

Overall

2003-2004

2005-2006

2007-2008

2009-2010

2011–2012

2013-2014

N = 1443

N = 1418

N = 1664

N = 1884

N = 1557

N = 1698

N = 9664

CONTINUOUS, mean(SD)

 Age, years

51.0 (19.5)

48.3 (18.8)

50.2 (17.6)

49.4 (17.8)

48.0 (17.7)

48.3 (17.2)

49.2 (17.2)

 BMI, kg/m2

28.6 (6.32)

28.7 (6.70)

28.7 (6.13)

29.1 (6.86)

28.7 (6.90)

29.1 (7.11)

28.8 (6.69)

 GGT, U/L

21.5 (1.91)

20.85 (1.96)

24.1 (1.92)

22.1 (1.92)

20.5 (1.92)

21.3 (1.96)

21.7 (1.94)

 SBP, mm Hg

126.0 (20.7)

123.0 (19.3)

123.7 (18.6)

121.9 (18.4)

122.5 (17.8)

122.6 (17.5)

123.2 (18.7)

 DBP, mm Hg

70.3 (12.3)

69.1 (12.7)

70.4 (11.8)

69.0 (12.2)

71.0 (11.8)

70.2 (11.3)

70.0 (12.0)

CATEGORICAL, N (%)

 Female

839 (52.08)

825 (51.79)

966 (50.31)

1078 (52.00)

871 (49.77)

961 (51.72)

4911 (50.82)

 Race/Ethnicity

  Mexican American

323 (20.05)

311 (19.52)

322 (16.77)

384 (18.52)

154 (8.80)

267 (14.37)

1618 (16.74)

  Other Hispanic

39 (2.42)

47 (2.95)

234 (12.19)

217 (10.47)

179 (10.23)

159 (8.56)

779 (8.06)

  Non-Hispanic White

852 (52.89)

816 (51.22)

893 (46.51)

973 (46.94)

639 (36.51)

805 (43.33)

4501 (46.57)

  Non-Hispanic Black

341 (21.17)

363 (22.79)

402 (20.94)

372 (17.95)

458 (26.17)

370 (19.91)

1976 (20.45)

  Other

56 (3.48)

56 (3.52)

69 (3.59)

127 (6.13)

320 (18.29)

257 (13.83)

790 (8.17)

 Smoking Status

  Never

830 (51.55)

843 (52.92)

1015 (52.89)

1116 (53.84)

1002 (57.29)

1044 (56.19)

5242 (54.24)

  Former

337 (20.93)

338 (21.22)

428 (22.30)

444 (21.42)

340 (19.44)

376 (20.24)

2000 (20.70)

  Current

443 (27.52)

412 (25.86)

476 (24.80)

513 (24.75)

407 (23.27)

438 (23.57)

2422 (25.06)

 Education

   < High School

486 (30.25)

450 (28.28)

611 (31.82)

591 (28.55)

420 (24.03)

393 (21.16)

2599 (26.89)

  High School

850 (52.89)

836 (52.54)

966 (50.32)

1082 (52.27)

872 (49.89)

996 (53.64)

5018 (51.92)

  College or Above

271 (16.86)

305 (19.17)

343 (17.86)

397 (19.18)

456 (26.09)

468 (25.20)

2047 (21.18)

 Hypertension

549 (40.76)

450 (33.06)

608 (37.98)

666 (36.78)

550 (36.74)

595 (36.28)

3418 (36.92)

 Mortality

       

  Total

163 (11.32)

102 (7.19)

62 (3.73)

32 (1.70)

NA

NA

359 (5.61)

  CVD

42 (2.92)

33 (2.33)

17 (1.02)

2 (0.11)

NA

NA

94 (1.47)

  Cancer

38 (2.64)

25 (1.76)

14 (0.84)

13 (0.69)

NA

NA

90 (1.41)

  1. BMI body mass index, GGT gamma-glutamyl transferase, SBP systolic blood pressure, DBP diastolic blood pressure, CVD cardiovascular disease