Household Environmental Factors for Incidence of Respiratory Symptoms in Adolescents

背景：氣喘是孩童和青少年時期最常見的慢性呼吸道發炎性疾病，盛行率在世界多數國家包括台灣仍呈現一個上升的趨勢。氣喘發作時易在夜間或清晨反覆出現呼吸喘鳴、呼吸困難、胸悶及咳嗽等症狀，有時與支氣管炎的臨床表現常不易區別，但兩者皆會影響青少年的生活及學習，帶給個人、家庭及社會重大的衝擊及損耗。氣喘及支氣管炎的致病機轉相當複雜，基本上可分為宿主及環境因子兩大類，環境因素包含室內過敏原、感染及菸害等，過去針對室內環境因子對於呼吸道健康的相關性研究多來自橫斷性或病例對照研究，且針對青少年族群也相對較少。 研究方法：本研究設計為追蹤研究，我們於2007年在台灣隨機選取14個不同社區內國中7、8、9年級的學生(12-14歲)，以問卷收集個人及家庭健康狀況和室內環境因子及菸害暴露資料，當年度完成問卷者有5091位學生，回答率為87.7%。在2009年追蹤研究時我們排除了2007年為8、9年級學生共957位學生，對當時為7年級4134位青少年進行追蹤問卷研究。在結果定義方面，如2007年回答無呼吸道症狀而在2009年回答有的青少年，即視為一個呼吸道症狀新發生個案；暴露及相關干擾因子資料則以基礎問卷獲得。室內環境因子與菸害對於呼吸道疾病及症狀發生藉由布阿松迴歸(Poisson regression)模型來檢視其相關性，對於研究設計上的多重檢定影響，則以Bonferroni法進行校正。 研究結果：2009年追蹤到的總人數為3909人(追蹤率94.6%)。呼吸道症狀的兩年累積發生率介於1.4?18.5%。經過校正年齡、性別、父母的氣喘及過敏病史，母親在懷孕過程中有無吸菸、青少年的身體質量指數及社區之後，青少年本身吸菸會增加運動中或運動後呼吸道喘鳴(RR=1.45; 95% CI=1.01-2.08)、慢性咳嗽(RR=1.77; 95% CI=1.04-3.00)及沒感冒時就胸腔卡痰或咳痰危險性( RR=1.65; 95% CI= 1.03-2.66)，而且青少年的吸菸量及菸齡對於慢性咳嗽及沒感冒時就胸腔卡痰或咳痰的危險性呈現劑量效應關係。二手菸暴露會造成慢性咳嗽發生危險性增加，不論是由終生暴露(RR=1.40; 95% CI=1.04-1.88)或目前仍有暴露來看皆有顯著的相關性(RR=1.35; 95% CI=1.01-1.81)，且接觸二手菸時間長短與慢性咳嗽的發生危險性上呈現劑量效應。青少年已有氣喘或喘鳴疾病史並接觸二手菸，不論是終生暴露或是目前仍有暴露，會顯著增加沒感冒時就胸腔卡痰或咳痰發生的危險性，且具有交互作用(p for interaction=0.05; 0.03)。在本研究中，室內家中飼養寵物及潮濕因子對於呼吸道疾病的發生並無顯著的統計相關。 結論：本研究發現在台灣青少年中，自己吸菸會增加運動中或運動後呼吸道喘鳴及支氣管症狀發生的危險性；在家中暴露於二手菸則與支氣管症狀發生具有正相關。Background: The risk of asthma and respiratory symptoms associated with indoor environmental risk factors and tobacco smoke has been examined in both cross-sectional and prospective studies of younger children. However, few studies have investigated the role of the same exposures on respiratory symptoms onset during adolescence. We examined the association of indoor environmental factors and tobacco smoke with the subsequent development of asthma and respiratory symptoms among cohorts of Taiwanese adolescents. Methods: Risk factors for the development of asthma, wheezing disorders and bronchitic symptoms were examined in Taiwan Children Health Study (TCHS) of 3909 7th grade adolescents from 14 different communities in Taiwan at 2007 entry into the study, who were followed for up to 2 years. Newly diagnosed cases of respiratory conditions were identified by follow-up questionnaire in 2009. The risk associated with indoor risk factors and tobacco smoke assessed by questionnaire at entry into the study was examined using Poisson regression model with Bonferroni adjustment for multiple comparison. Results: The cumulative incidences of asthma, wheezing disorders and bronchitic symptoms are between 1.4~18.5%. Tobacco smoke was associated with increased risks of developing exercise induced wheeze and bronchitic symptoms. Adolescents who reported smoking had a relative risk (RR) of 1.45(95% confidence interval [CI]=1.01-2.08) for new-onset exercise induced wheeze compared with nonsmokers . The effects of current (RR=1.35; 95% CI=1.01-1.81) and lifetime (RR=1.40; 95% CI=1.04-1.88) secondhand smoke (SHS) were associated with increased risk on chronic cough. An increased risk on developing chronic cough (RR=1.77; 95% CI=1.04-3.00) and phlegm without having cold (RR=1.65; 95% CI=1.03-2.66) with active smoking were noted. The interaction of SHS with asthma or wheeze history of participants at baseline was significant on developing bronchitic symptoms. In our study, there was no significant association between raising furry pets at home, indoor dampness and respiratory symptoms development. Conclusion: We conclude that tobacco smoke is a risk factor for new-onset exercise induced wheeze and bronchitic symptoms in Taiwanese adolescents