Scanlon P D, Connett J E, Waller L A, Altose M D, Bailey W C, Buist A S, Tashkin D P
Division of Pulmonary and Critical Care Medicine, Mayo Foundation, Rochester, Minnesota 55905, USA.
Am J Respir Crit Care Med. 2000 Feb;161(2 Pt 1):381-90. doi: 10.1164/ajrccm.161.2.9901044.
Previous studies of lung function in relation to smoking cessation have not adequately quantified the long-term benefit of smoking cessation, nor established the predictive value of characteristics such as airway hyperresponsiveness. In a prospective randomized clinical trial at 10 North American medical centers, we studied 3, 926 smokers with mild-to-moderate airway obstruction (3,818 with analyzable results; mean age at entry, 48.5 yr; 36% women) randomized to one of two smoking cessation groups or to a nonintervention group. We measured lung function annually for 5 yr. Participants who stopped smoking experienced an improvement in FEV(1) in the year after quitting (an average of 47 ml or 2%). The subsequent rate of decline in FEV(1) among sustained quitters was half the rate among continuing smokers, 31 +/- 48 versus 62 +/- 55 ml (mean +/- SD), comparable to that of never-smokers. Predictors of change in lung function included responsiveness to beta-agonist, baseline FEV(1), methacholine reactivity, age, sex, race, and baseline smoking rate. Respiratory symptoms were not predictive of changes in lung function. Smokers with airflow obstruction benefit from quitting despite previous heavy smoking, advanced age, poor baseline lung function, or airway hyperresponsiveness.
先前有关戒烟与肺功能关系的研究，并未充分量化戒烟的长期益处，也未确定诸如气道高反应性等特征的预测价值。在北美10个医学中心进行的一项前瞻性随机临床试验中，我们研究了3926名患有轻至中度气道阻塞的吸烟者（3818名有可分析结果；入组时平均年龄48.5岁；36%为女性），他们被随机分为两个戒烟组之一或一个非干预组。我们每年测量肺功能，持续5年。戒烟的参与者在戒烟后的第一年FEV(1)有所改善（平均增加47毫升或2%）。持续戒烟者中FEV(1)随后的下降速率是继续吸烟者的一半，分别为31±48与62±55毫升（平均值±标准差），与从不吸烟者相当。肺功能变化的预测因素包括对β受体激动剂的反应性、基线FEV(1)、乙酰甲胆碱反应性、年龄、性别、种族和基线吸烟率。呼吸道症状并不能预测肺功能的变化。患有气流阻塞的吸烟者，无论先前吸烟量多大、年龄多大、基线肺功能多差或气道高反应性如何，戒烟均有益处。
