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ANTIOXIDANT SUPPLEMENTATION AND LUNG FUNCTIONS AMONG ASTHMATIC CHILDREN EXPOSED TO HIGH LEVELS OF AIR POLLUTANTS
Citation:
Romieu, I., J. J. SienraMonge, M. Ramirez, M. M. TellezRojo, H. MorenoMacias, N. I. ReyesRuiz, B. E. del RioNavarro, G. E. Hatch, R. Slade, AND M. HernandezAvila. ANTIOXIDANT SUPPLEMENTATION AND LUNG FUNCTIONS AMONG ASTHMATIC CHILDREN EXPOSED TO HIGH LEVELS OF AIR POLLUTANTS. AMERICAN JOURNAL OF RESPIRATORY AND CRITICAL CARE MEDICINE 166:703-709, (2002).
Description:
Abstract
Air pollutant exposure has been related to adverse respiratory effects, in particular, in asthmatics. This effect could be the consequence of the oxidative stress caused by air pollutants on the lung. Antioxidant vitamins are free- radical scavengers, and could have a protective effect against photo-oxidant exposure. To evaluate whether acute effects of ozone and PM10 could be attenuated by antioxidant vitamin supplementation, we conducted a randomized trial using a double-blinded design. Asthmatic children (n=158) residents of Mexico City were randomly assigned to take a daily supplement (50 mg/day vitamin E, 250 mg/day vitamin C) or a placebo and were followed from October 1998 to April 2000. Pulmonary function tests were done twice a week in the morning. During the follow-upobservation period, the mean 1-h maximum ozone level was 102 ppb (SD= 47) and the mean 24-h average PM10 level was 56.7 mg/m3 (SD=27.4). Ozone levels 1 day prior to the spirometry were inversely associated significantly with FEF25-75 (-14.32 m.l s-1/ 10 ppb; p<0.01) and FEV1 (-5.79 ml 10/ppb; p<0.05) in the placebo groups among moderate and severe asthmatics. No significant changes were observed in the supplement group. The modulation of the effect of ozone on lung function by the supplement was calculated to be 3.6% for FEF25-75 and 1.5% for FEV1 for an increase of 50 ppb in 1-hr maximum ozone levels one day prior to the spirometry. When we restricted the analysis to days having PM10 levels exceeding 70 mg/m3, the modulating effect reached 7.0% for FEF25-75 and 2.3% for FEV1. We conclude that supplementation with antioxidants modulate the impact of air pollutants levels in children with moderate to severe asthma.