Table 4

Relationship between antioxidants (vitamin C, vitamin E, and β-carotene) and respiratory symptoms or lung function (n = 6555)

Dependent variableVitamin CVitamin Eβ-carotene
OR4-150 OR4-151 95% CI4-151 OR4-150 OR4-151 95% CI4-151 OR4-150 OR4-151 95% CI4-151
Symptoms
 Cough (n = 6533)0.530.660.50 to 0.871.280.850.61 to 1.180.790.860.67 to 1.10
 Phlegm (n = 6541)0.670.770.59 to 1.021.321.060.76 to 1.471.041.110.87 to 1.40
 Productive cough
(n = 6536)
1.081.090.93 to 1.281.471.261.02 to 1.561.201.140.99 to 1.33
 Wheeze ( n = 6514)0.871.040.83 to 1.301.181.130.85 to 1.521.151.271.04 to 1.55
 SOB (n = 6494)0.750.810.61 to 1.070.881.240.87 to 1.770.871.000.77 to 1.29
 Nocturnal attacks SOB
( n = 6539)
0.900.950.72 to 1.251.101.200.84 to 1.711.161.220.96 to 1.56
Lung function Difference4-152 Difference4-153 95% CI 4-153 Difference4-152 Difference4-153 95% CI 4-153 Difference4-152 Difference4-153 95% CI 4-153
 FEV1 (n = 5740)91.152.923.0 to 82.333.027.9−12.9 to 68.783.260.031.4 to 88.6
 FVC (n = 5633)117.879.042.3 to 115. 766.318.2−32.2 to 68.6105.475.240.2 to 110.2
  • SOB = Shortness of breath.

  • 4-150 Unadjusted prevalence odds ratios (OR), presented for subjects in the 90th percentile versus those subjects in the 10th percentile of antioxidant intake—that is, for vitamin C intake 144.9 mg, for vitamin E intake 14.4 mg, and for β-carotene intake 2.50 mg.

  • 4-151 Prevalence odds ratios (with 95% confidence interval) adjusted for age, sex, energy intake, smoking status, pack years of smoking, presented for subjects in the 90th percentile versus those subjects in the 10th percentile of antioxidant intake.

  • 4-152 Difference in FEV1 and FVC (in ml for a standard height of 1.70 m) between subjects in the 90th percentile and those in the 10th percentile of antioxidant intake adjusted for age, age squared, and sex.

  • 4-153 Difference in FEV1 and FVC (in ml for a standard height of 1.70 m) with 95% confidence interval (95% CI) between subjects in the 90th percentile and those in the 10th percentile of antioxidant intake adjusted for age, age squared, sex, energy intake, smoking status, pack years of smoking.