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Age of asthma onset and vulnerability to ambient air pollution: an observational population-based study of adults from Southern Taiwan.

Wu TJ, Wu CF, Chen BY, Lee YL, Guo YL - BMC Pulm Med (2016)

Bottom Line: Data from 23,551 participants remained satisfactory with a response rate of 66 %.Among 20,508 participants aged 26-50 years, 703 questionnaire-determined asthmatics were identified and included for analysis.In adulthood, exposure to PM10 has a greater effect on late-onset asthma than early-onset asthma and deserves greater attention among ambient air pollutants.

View Article: PubMed Central - PubMed

Affiliation: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University, 17, Syujhou Road, Taipei, 100, Taiwan.

ABSTRACT

Background: Late-onset asthma (onset > 12 years) is pathologically distinct from early-onset asthma. The mechanism of air pollution is not a classic allergic inflammation and could have differential effect on late-onset and early-onset asthma. However, there is little known about the association of onset-age phenotype and air pollution. In this population-based study, we aimed to determine the association of asthma severity outcomes and air pollution regarding age at onset of asthma.

Methods: In 2004, we conducted a cross-sectional questionnaire survey about respiratory health among schoolchildren's parents randomly selected from 94 of 816 elementary and middle schools in southern Taiwan. Participants ever having typical asthma symptoms were enrolled. We used kriging method to estimate individual exposure to ambient air pollution in the preceding year before the year of asthma severity survey. Ordered logistic regression was used to determine the association of exposure and asthma severity scores. Age at asthma onset of 12 years was used as a cut-off to define early- or late-onset asthma.

Results: The study surveyed 35,682 participants. Data from 23,551 participants remained satisfactory with a response rate of 66 %. Among 20,508 participants aged 26-50 years, 703 questionnaire-determined asthmatics were identified and included for analysis. Using the median of PM10 (66 μg/m(3)) as a cut-off, those exposed to higher PM10 were more likely to have higher severity scores (OR = 1.74; 95 % CI, 1.13 - 2.70) only for asthmatics with asthma onset at > 12 years.

Conclusions: In adulthood, exposure to PM10 has a greater effect on late-onset asthma than early-onset asthma and deserves greater attention among ambient air pollutants.

No MeSH data available.


Related in: MedlinePlus

The flow chart describing the enrollment of study subjects and follow-up approach
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Fig1: The flow chart describing the enrollment of study subjects and follow-up approach

Mentions: The aim of this study was to evaluate the impact of air pollution on asthma severity and age of asthma onset. This observational study used a longitudinal approach in terms of the exposure in the preceding year to predict asthma severity in the following year (Fig. 1). As hospitalization and emergency department visits due to asthma attack were associated with ambient particulate matter in previous publication (estimated odds ratio = 1.7 by median of PM10) [26], the minimum sample size to reach 90 % of power and 0.05 of significance level for PM10 was calculated accordingly. The sample size to discriminate asthma severity outcomes by PM10 levels was calculated by proportion of 0.63 and 0.37 for exposed and non-exposed groups, respectively. As a result, the sample must include 168 asthmatics. Thus the reported number of asthmatics in this study was considered adequate for testing our hypothesis.Fig. 1


Age of asthma onset and vulnerability to ambient air pollution: an observational population-based study of adults from Southern Taiwan.

Wu TJ, Wu CF, Chen BY, Lee YL, Guo YL - BMC Pulm Med (2016)

The flow chart describing the enrollment of study subjects and follow-up approach
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4837625&req=5

Fig1: The flow chart describing the enrollment of study subjects and follow-up approach
Mentions: The aim of this study was to evaluate the impact of air pollution on asthma severity and age of asthma onset. This observational study used a longitudinal approach in terms of the exposure in the preceding year to predict asthma severity in the following year (Fig. 1). As hospitalization and emergency department visits due to asthma attack were associated with ambient particulate matter in previous publication (estimated odds ratio = 1.7 by median of PM10) [26], the minimum sample size to reach 90 % of power and 0.05 of significance level for PM10 was calculated accordingly. The sample size to discriminate asthma severity outcomes by PM10 levels was calculated by proportion of 0.63 and 0.37 for exposed and non-exposed groups, respectively. As a result, the sample must include 168 asthmatics. Thus the reported number of asthmatics in this study was considered adequate for testing our hypothesis.Fig. 1

Bottom Line: Data from 23,551 participants remained satisfactory with a response rate of 66 %.Among 20,508 participants aged 26-50 years, 703 questionnaire-determined asthmatics were identified and included for analysis.In adulthood, exposure to PM10 has a greater effect on late-onset asthma than early-onset asthma and deserves greater attention among ambient air pollutants.

View Article: PubMed Central - PubMed

Affiliation: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University, 17, Syujhou Road, Taipei, 100, Taiwan.

ABSTRACT

Background: Late-onset asthma (onset > 12 years) is pathologically distinct from early-onset asthma. The mechanism of air pollution is not a classic allergic inflammation and could have differential effect on late-onset and early-onset asthma. However, there is little known about the association of onset-age phenotype and air pollution. In this population-based study, we aimed to determine the association of asthma severity outcomes and air pollution regarding age at onset of asthma.

Methods: In 2004, we conducted a cross-sectional questionnaire survey about respiratory health among schoolchildren's parents randomly selected from 94 of 816 elementary and middle schools in southern Taiwan. Participants ever having typical asthma symptoms were enrolled. We used kriging method to estimate individual exposure to ambient air pollution in the preceding year before the year of asthma severity survey. Ordered logistic regression was used to determine the association of exposure and asthma severity scores. Age at asthma onset of 12 years was used as a cut-off to define early- or late-onset asthma.

Results: The study surveyed 35,682 participants. Data from 23,551 participants remained satisfactory with a response rate of 66 %. Among 20,508 participants aged 26-50 years, 703 questionnaire-determined asthmatics were identified and included for analysis. Using the median of PM10 (66 μg/m(3)) as a cut-off, those exposed to higher PM10 were more likely to have higher severity scores (OR = 1.74; 95 % CI, 1.13 - 2.70) only for asthmatics with asthma onset at > 12 years.

Conclusions: In adulthood, exposure to PM10 has a greater effect on late-onset asthma than early-onset asthma and deserves greater attention among ambient air pollutants.

No MeSH data available.


Related in: MedlinePlus