Lim T K, Taylor R G, Watson A, Joyce H, Pride N B
Department of Medicine, Royal Postgraduate Medical School, Hammersmith Hospital, London.
Thorax. 1988 Aug;43(8):599-604. doi: 10.1136/thx.43.8.599.
Bronchial hyperresponsiveness to inhaled histamine in smokers is associated with an accelerated annual decline in FEV1 and low baseline FEV1 values. The evolution of bronchial hyperresponsiveness and whether it precedes or follows the accelerated decline in FEV1 and reduction in FEV1 is unknown. Measurements of the provocative concentration of inhaled histamine required to reduce FEV1 by 20% (PC20) were repeated after a four year interval in 27 male smokers (mean age 59 years, smoking on average 27 cigarettes a day in 1986) and 16 men who were ex-smokers in 1982 and who remained non-smokers until 1986 (mean age 53 years in 1986). These men were originally recruited to a prospective study in 1974 and had their first PC20 measurement in 1982. PC20 was positively related to baseline FEV1 in both smokers and ex-smokers in both 1982 and 1986 (r ranging from 0.56 to 0.76, p less than 0.01). In smokers mean FEV1 fell from 83% to 77% predicted (p less than 0.001) and geometric mean PC20 from 7.11 to 3.27 mg/ml (p less than 0.001) between 1982 and 1986. The change in PC20 in individual smokers over the four years was related to change in FEV1 (p = 0.012). In ex-smokers mean FEV1 was 93% predicted both in 1982 and in 1986 and there was no significant difference in geometric mean PC20 between 1982 (6.68 mg/ml) and 1986 (5.98 mg/ml). Thus in smokers there was an accelerated annual decline in FEV1 and an increase in bronchial hyperresponsiveness as FEV1 fell. The ex-smokers had comparable levels of bronchial hyperresponsiveness in 1982. Mean PC20 values were unchanged in 1986 in these men, who showed a normal age related decline in FEV1. These longitudinal results emphasise the importance of baseline airway geometry in influencing bronchial hyperresponsiveness to histamine in middle aged smokers and ex-smokers.
吸烟者对吸入组胺的支气管高反应性与第一秒用力呼气容积（FEV1）的年下降加速及FEV1的低基线值相关。支气管高反应性的演变以及它是先于还是后于FEV1的加速下降和FEV1的降低尚不清楚。对27名男性吸烟者（平均年龄59岁，1986年平均每天吸烟27支）和16名1982年已戒烟且至1986年仍不吸烟的男性（1986年平均年龄53岁），在间隔四年后重复测量使FEV1降低20%所需的吸入组胺激发浓度（PC20）。这些男性最初于1974年被纳入一项前瞻性研究，并于1982年首次进行PC20测量。在1982年和1986年，吸烟者和已戒烟者的PC20均与基线FEV1呈正相关（r范围为0.56至0.76，p<0.01）。在吸烟者中，1982年至1986年间，FEV1预计值从83%降至77%（p<0.001），几何平均PC20从7.11降至3.27mg/ml（p<0.001）。个体吸烟者在四年间PC20的变化与FEV1的变化相关（p = 0.012）。在已戒烟者中，1982年和1986年FEV1预计值均为93%，1982年（6.68mg/ml）和1986年（5.98mg/ml）的几何平均PC20无显著差异。因此，在吸烟者中，随着FEV1下降，FEV1年下降加速且支气管高反应性增加。已戒烟者在1982年有相当水平的支气管高反应性。这些男性在1986年的平均PC20值未改变，其FEV1随年龄呈正常下降。这些纵向研究结果强调了基线气道几何结构在影响中年吸烟者和已戒烟者对组胺的支气管高反应性方面的重要性。
