Table 3.

Effects of antioxidant micronutrients on inflammatory cytokines and oxidative stress markers in plasma by current smoking status

Biomarkersn placebo/antioxidants*Placebo, mean (SD)Antioxidants, mean (SD)*Absolute treatment effects, mean (95% CI)Relative treatment effectsP§
Nonsmokers
IL-6 (pg/mL)13/13
    Baseline1.26 (1.94)2.04 (2.83)
    4 mo2.46 (2.02)1.51 (1.82)−0.97 (−2.13 to 0.19)0.380.10
TNF-α (pg/mL)12/14
    Baseline2.29 (1.60)2.69 (1.50)
    4 mo3.85 (1.98)2.22 (1.33)−2.02 (−2.87 to −1.17)0.50<0.0001
F2-isoprostane (pg/mL)13/14
    Baseline2,047 (788)2,090 (2,157)
    4 mo2,253 (807)1,835 (620)−461 (−1,678 to 755)0.800.44
CySS (μmol/L/mL)12/14
    Baseline32.6 (32.6)40.8 (20.6)
    4 mo41.5 (15.9)24.5 (13.9)−25.1 (−43.1 to −7.2)0.470.008
Current smokers
IL-6 (pg/mL)9/9
    Baseline1.20 (1.66)0.52 (2.53)
    4 mo1.74 (2.45)1.87 (2.14)0.94 (−0.82 to 2.70)2.480.27
TNF-α (pg/mL)9/9
    Baseline2.80 (1.50)3.49 (2.21)
    4 mo3.28 (1.37)3.63 (1.69)−0.33 (−1.72 to 1.05)0.890.61
F2-isoprostane (pg/mL)8/8
    Baseline1,855 (535)1,650 (552)
    4 mo2,133 (755)2,665 (997)736 (−377 to 1,850)1.400.18
CySS (μmol/L/mL)10/9
    Baseline41.8 (25.3)31.4 (20.7)
    4 mo42.3 (13.5)27.8 (13.2)−4.0 (−26.7 to 18.6)0.880.71
  • *The antioxidant cocktail consists of 800 mg dl-α-tocopherol acetate, 24 mg β-carotene, 1.0 g vitamin C, 200 μg l-selenomethionine, 7.2 mg riboflavin, 80 mg niacin, 60 mg zinc, and 5 mg manganese, given daily over 4 mo.

  • Absolute treatment effect is the absolute change from baseline to follow-up in the treatment group minus the absolute change from baseline to follow-up in the placebo group from mixed model.

  • Relative treatment effect is defined as (treatment group follow-up/treatment group baseline)/(placebo follow-up/placebo baseline). The interpretation of the relative effect is similar to that of an odds ratio (e.g., a relative effect of 2.0 would mean that the relative proportional change in the treatment group was twice as great as that in the placebo group).

  • §P values for baseline to follow-up differences between placebo group and active treatment group from mixed model.

  • Geometric means with SDs are reported, calculated by exponentiating the mean of the log-transformed values.