哮喘联盟

    背景：许多研究发现，空气质量的改善能减少死亡率，我们研究组也发现，空气微粒水平的下降能明显抑制成人肺功能的下降。本试验研究PM10（微粒的空气动力学直径< 10微米）的降低是否与呼吸系统症状发生率下降有关。
    方法：7019名研究对象在1991年进行了全面的基线检查，并开始随访性面谈至2002年。以模型为基础，对每位对象健康检查前12个月暴露的平均PM10进行估算，用他们的差值作为暴露变量（DeltaPM10）。根据基线症状进行分层分析，随访期间DeltaPM10和症状变化之间的关系根据重要的基线特征、随访期间吸烟状态和季节进行校正。然后对随访期间症状的校正优势比以及因为PM10下降而减少的有症状患者的数量进行评估。
    结果：2002年居民PM10的暴露显著低于1991年（平均下降6.2 microg/m3, SD = 3.9 microg/m3）。由于PM10水平的变化，估计受益者（每10000人）为：常规咳嗽患者中小于259人（95%-CI: 102～416）；慢性咳嗽或粘痰患者中小于179人（30～328）；无呼吸的喘息患者中小于137人（9～266）。
    结论：在11年的随访期中，空气微粒水平下降对于成人呼吸道症状的发生具有有益影响。

（林江涛 审校）
Schindler C, et al. Am J Respir Crit Care Med. 2009 Jan 22. [Epub ahead of print]

Improvements in PM10-Exposure and Reduced Rates of Respiratory Symptoms in a Cohort of Swiss Adults (SAPALDIA-study).

BACKGROUND: Reductions in mortality following improvements in air quality were documented by several studies and our group has found decreasing particulate levels to attenuate lung function decline in adults. We therefore aimed to investigate whether decreases in PM10 (particulates with an aerodynamic diameter < 10 microm) were also associated with lower rates of reporting respiratory symptoms (i.e., decreased morbidity) on follow-up.
METHODS: The present analysis includes 7019 subjects who underwent detailed baseline examinations in 1991 and a follow-up interview in 2002. Each subject was assigned model-based estimates of average PM10 during the 12 months preceding each health assessment and their difference was used as exposure variable of interest (DeltaPM10). Analyses were stratified by symptom status at baseline and associations between DeltaPM10 and change in symptom status during follow-up were adjusted for important baseline characteristics, smoking status at follow-up and season. We then estimated adjusted odds ratios for symptoms at follow-up and numbers of symptomatic cases prevented due to the observed reductions in PM10.
RESULTS: Residential exposure to PM10 was lower in 2002 than in 1991 (mean decline 6.2 microg/m(3), SD = 3.9 microg/m(3)). Estimated benefits (per 10,000 persons) attributable to the observed changes in PM10-levels were: 259 (95%-CI: 102 to 416) fewer subjects with regular cough, 179 (30 to 328) fewer subjects with chronic cough or phlegm and 137 (9 to 266) fewer subjects with wheezing with breathlessness.
Interpretation: Reductions in particle levels in Switzerland over the 11 year follow-up period had a beneficial effect on respiratory symptoms among adults.