Effect of Vitamin E on Exhaled Ethane in Cigarette Smokers: Results
The demographic profiles of the subjects recruited for this study appear in Table 1. Most subjects were male (86%), reflecting the largely male population of patients at the Veterans Affairs Medical Center. They ranged in age from 42 to 75 years with the mean (± SD) being 59.5 (± 10.4) years. These subjects smoked a mean (± SD) of 50.9 (± 20.52) pack-years overall with a range of between 7.5 and 90 pack-years. Mean (± SD) FEV1 as percent predicted was 78.6% (± 21.6) with a range from 40 to 121%. The Mean FEV1/FVC ratio was 63.9% with a range of 49 to 86%.
The results of the food frequency questionnaire showed an average daily vitamin A intake of 8,996.9 IU, a vitamin C intake of 115.2 mg, and vitamin E intake of 8.4 tocopherol equivalents (Table 2). Total caloric intake was within the acceptable normal range.
There were no statistically significant differences in ethane values measured at any time point. Values for exhaled ethane were (mean ± SD)(pm/min/kg) as follows: at baseline (study entry), 7.39 ± 5.39; postplacebo run-in, 6.86 ± 4.09; after vitamin E, 6.36 ± 3.02; and final, 7.23 ± 4.63. Since ethane values at study entry were performed when vitamin intake was uncontrolled, ethane exhaled may be influenced by both prooxidant and antioxidant vitamins so purchase zyrtec. Since vitamin intake was better controlled at the last three time points, it is on these three time points that we concentrate our analysis and discussion.
Figure 1 shows the association between pack-years and exhaled ethane level after placebo run-in (top, A), after vitamin E (center, B), and at the final visit (bottom, C). At all time points, there was a positive association between oxidant load and exhaled ethane. These correlations were statistically significant only after vitamin E treatment (Fig 1, center, B).
Figure 2 shows the relationship between pack-years and one measurement of lung function (FEV1/ FVC). As expected, there was a significant negative association between these two variables.
|Age, yr, mean ± SD||59.5 ± 10.4|
|FEVj, % predicted, mean ± SD||78.6 ± 21.6|
|FEVj/FVC, %, mean ± SD||63.9 ± 11.5|
|FEVj, L, mean ± SD||2.25 ± 0.74|
|Pack-years ± SD||50.97 ± 20.52|
Table 2—Daily Dietary Intake as per Food Frequency Questionnaire
|Vitamin A, IU||8,996.9||6,428.1||4-5,000|
|Vitamin C, mg||115.2||88.8||60|
|Vitamin E, TE mg||8.4||4.2||8-10|
Figure 1. Effect of pack-years of smoking on exhaled ethane after placebo run-in (top, A), after vitamin E treatment (center, B), and at final visit (bottom, C). After supplementation with vitamin E (center, B), there was a statistically significant positive correlation between exhaled ethane and pack-years of smoking.
Figure 2. As expected, pack-years of smoking was inversely related to lung function as measured by the FEV1/FVC ratio.