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Table 4 Maternal characteristics associated with dietary nitrosamine intake, National Birth Defects Prevention Study Controls, 1997-2004

From: Maternal characteristics associated with the dietary intake of nitrates, nitrites, and nitrosamines in women of child-bearing age: a cross-sectional study

 

Nitrosamine intake μg/day

 

Odds ratios and 95% confidence intervalsb

 

Quartile 1a

Quartile 2

Quartile 3

Quartile 4

   
 

<0.3330

0.3330-0.4715

0.4716-0.6685

>0.6685

p-value

4th quartile compared to the 1st quartile

 

n

%

n

%

n

%

n

%

 

Crude

Adjustedc

Race/Ethnicity

           

   White non-Hispanic

761

21.8

894

25.7

917

26.3

912

26.2

<0.0001

1.0

1.0

   Black non-Hispanic

203

30.8

158

23.9

152

23.0

147

22.3

 

0.60 (0.48,0.76)

0.36 (0.26,0.50)

   Hispanic

357

27.5

315

24.2

318

24.5

310

23.8

 

0.73 (0.61,0.87)

0.35 (0.26,0.48)

   Asian/Pacific Islander

68

40.2

32

18.9

29

17.2

40

23.7

 

0.49 (0.33,0.73)

0.33 (0.19,0.57)

   Other

53

31.6

45

26.8

34

20.2

36

21.4

 

0.57 (0.37,0.87)

0.42 (0.24,0.74)

   Missing

9

40.9

7

31.8

1

4.5

5

22.7

   

Area of residence (state)

           

   Texas

168

24.6

166

24.3

176

25.7

174

25.4

<0.0001

1.0

1.0

   Arkansas

151

21.4

150

21.2

193

27.3

213

30.1

 

1.4 (1.0,1.8)

1.0 (0.69,1.6)

   California

235

30.1

174

22.2

171

21.9

202

25.8

 

0.83 (0.63,1.1)

0.73 (0.51,1.0)

   Georgia

185

30.1

158

25.7

151

24.7

120

19.5

 

2.5 (1.8,3.4)

3.6 (2.4,5.5)

   Iowa

100

15.5

118

18.3

168

26.1

258

40.1

 

0.55 (0.40,0.75)

0.66 (0.44,1.0)

   Massachusetts

208

28.0

226

30.4

191

25.7

118

15.9

 

0.84 (0.61,1.2)

0.87 (0.57,1.3)

   New Jersey

141

25.0

160

28.4

141

25.0

122

21.6

 

0.75 (0.54,1.0)

0.82 (0.53,1.3)

   New York

135

26.0

156

30.1

123

23.7

105

20.2

 

0.63 (0.46,0.86)

0.67 (0.44,1.0)

   North Carolina

84

29.0

87

30.0

64

22.0

55

19.0

 

0.63 (0.42,0.94)

0.49 (0.29,0.83)

   Utah

44

17.2

56

21.9

73

28.5

83

32.4

 

1.8 (1.2,2.8)

1.8 (1.0,3.0)

Dietary folate (μg/day)

           

   <319

619

43.0

386

26.8

273

19.1

160

11.1

<0.0001

1.0

1.0

   319-465

362

24.9

414

28.5

395

27.2

281

19.4

 

3.0 (2.4,3.8)

1.7 (1.3,2.3)

   465 - ≤685.5

288

19.7

368

25.2

416

28.4

390

26.7

 

5.2 (4.2,6.6)

2.0 (1.5,2.7)

   > 685.5

182

12.5

283

19.5

367

25.3

619

42.7

 

13.2 (10.4,16.7)

3.4 (2.4,4.7)

Maternal education (years at school)

           

   16+

402

22.0

508

27.8

485

26.6

431

23.6

<0.0001

1.0

1.0

   12-15

343

22.3

384

24.9

404

26.2

409

26.6

 

1.1 (0.91,1.4)

0.74 (0.58,0.96)

   12

404

28.0

356

24.7

330

22.8

354

24.5

 

0.82 (0.67,0.99)

0.38 (0.29,0.50)

   9-11

209

30.0

143

20.6

161

23.1

183

26.3

 

0.82 (0.64,1.0)

0.33 (0.24,0.47)

   0-8

83

29.9

57

20.5

67

24.1

71

25.5

 

0.80 (0.57,1.1)

0.37 (0.23,0.61)

   Missing

10

52.6

3

15.8

4

21.1

2

10.5

   

Dietary fat (% of daily calories)

           

   ≤ 30%

1034

31.9

871

26.9

726

22.5

606

18.7

<0.0001

1.0

1.0

   >30%

417

16.3

580

22.5

725

28.3

844

32.9

 

3.5 (3.0,4.0)

8.5 (6.9,10.4)

Maternal household income (dollars annually)

           

   ≥50,000

415

22.7

517

28.2

490

26.8

409

22.3

<0.0001

1.0

---

   40-49,999

92

21.8

114

27.0

91

21.6

125

29.6

 

1.4 (1.0,1.9)

---

   30-39,999

123

22.8

135

25.0

141

26.1

141

26.1

 

1.2 (0.88,1.5)

---

   20-29,999

192

25.8

182

24.4

196

26.3

175

23.5

 

0.92 (0.72,1.2)

---

   10-19.999

173

24.0

181

25.0

165

22.9

203

28.1

 

1.2 (0.93,1.5)

---

   < 10,000

267

28.6

199

21.4

223

23.9

243

26.1

 

0.92 (0.74,1.2)

---

   Missing

189

30.9

123

20.0

145

23.7

154

25.2

 

---

---

Pre-pregnancy BMI

           

   Normal weight (18.5 - 25.0)

792

25.2

772

24.6

790

25.2

783

25.0

<0.0001

1.0

---

   Under weight (<18.5)

89

28.3

86

27.4

75

23.9

64

20.4

 

0.73 (0.52,1.0)

---

   Over weight (25.0 - 30.0)

291

23.5

321

25.8

317

25.6

311

25.1

 

1.1 (0.90,1.31)

---

   Obese (>30.0)

206

23.3

209

23.7

222

25.1

246

27.9

 

1.2 (0.97,1.5)

---

   Missing

73

31.9

63

27.5

47

20.5

46

20.1

 

---

---

Folic acid containing supplements

           

   No

715

27.5

599

23.0

624

24.1

661

25.4

<0.0001

1.0

---

   Yes

725

22.8

844

26.6

824

25.9

783

24.7

 

1.2 (1.0,1.4)

---

   Missing

11

39.3

8

28.6

3

10.7

6

21.4

 

---

---

Multivitamin use

           

   No

864

24.3

935

26.3

896

25.2

860

24.2

0.0020

1.0

---

   Yes

579

26.0

511

23.0

551

24.8

582

26.2

 

1.0 (0.87,1.2)

---

   Missing

8

32.0

5

20.0

4

16.0

8

32.0

 

---

---

Age at conception

           

   20-24

348

25.8

317

23.5

331

24.6

351

26.1

<0.0001

1.0

---

   <20

274

33.4

171

20.9

184

22.4

191

23.3

 

0.69 (0.54,0.88)

---

   25-29

350

22.5

418

26.9

391

25.1

397

25.5

 

1.1 (0.91,1.4)

---

   30-34

330

23.2

375

26.4

356

25.1

359

25.3

 

1.1 (0.87,1.3)

---

   35+

149

22.6

170

25.8

189

28.6

152

23.0

 

1.0 (0.77,1.3)

---

  1. aReferent category is nitrosamine intake at the lowest quartile of intake (<0.33299 μg/day)
  2. bOnly presented for variables included in the final multinomial logistic regression model
  3. cAdjusted for tertiles of daily caloric intake, race/ethnicity, maternal education, state of residence, dietary fat intake, and dietary folate as dietary folate equivalents. intake, pre-pregnancy body mass index, and folic acid supplementation
  4. Note: p-value excludes missing values
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Environmental Health

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