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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