Ulrik C S, Frederiksen J
Department of Clinical Physiology and Nuclear Medicine, National University Hospital, Copenhagen, Denmark.
Chest. 1995 Jul;108(1):10-5. doi: 10.1378/chest.108.1.10.
According to national health statistics, mortality rates for asthma have been increasing steadily over the past decades. Mortality and markers of risk of death from asthma were studied among asthmatics attending a chest clinic in Copenhagen between 1974 and 1990.
The study group consisted of 1,075 asthmatics in whom the diagnosis of asthma had been verified by objective/paraclinical criteria; they were compared with a sex- and age-matched group of nonasthmatic patients. Both groups of subjects comprised 425 men (mean age, 37.3 years [SD 15.2]) and 650 women (mean age, 38.5 years [SD 16.0]), and the mean follow-up period was 8.6 years (SD 4.2) in both asthmatics and controls.
Mortality from all causes was significantly increased in the asthmatic subjects (93 deaths) compared with the control group (41 deaths); relative risk [RR], 2.4; 95% confidence interval [CI], 1.6 to 3.4). The predominant cause of excess mortality was obstructive pulmonary disease, that is, status asthmaticus (14 vs 0 deaths, RR 8.2) and COPD not classified as status asthmaticus (19 vs 0 deaths, RR 8.3). Overall, 91% of the asthmatic cohort survived the mean follow-up period of almost 9 years compared with 96% of the controls. Mortality analysis employing the multiple regression model of Cox revealed that age, pack-years of smoking, eosinophilia, level of FEV1 percent predicted, and degree of reversibility in FEV1 were significant predictors of death from asthma, whereas no association was found between previous hospital admissions for asthma and subsequent death from asthma. In subjects with eosinophil (> 0.45 mia [10(9)/L]), the risk of dying from asthma was 7.4 (CI 2.8 to 19.7) greater than in those without eosinophilia. Compared with subjects with 15 to 24% reversibility in FEV1, the subjects with 25 to 49% and > 50% reversibility had a 2.7 and 7.0 higher risk of death from asthma, respectively.
Mortality was significantly increased in asthmatics compared with matched controls, primarily because of death from acute and chronic asthma. Furthermore, the present findings suggest that eosinophilia and pronounced increase in FEV1 after bronchodilator are strong markers of subsequent risk of death from asthma.
根据国家卫生统计数据，在过去几十年中，哮喘死亡率一直在稳步上升。对1974年至1990年间在哥本哈根一家胸部诊所就诊的哮喘患者的死亡率及死亡风险标志物进行了研究。
研究组由1075名哮喘患者组成，其哮喘诊断已通过客观/辅助临床标准得到证实；将他们与性别和年龄匹配的非哮喘患者组进行比较。两组受试者均包括425名男性（平均年龄37.3岁[标准差15.2]）和650名女性（平均年龄38.5岁[标准差16.0]），哮喘患者组和对照组的平均随访期均为8.6年（标准差4.2）。
与对照组（41例死亡）相比，哮喘患者组的全因死亡率显著增加（93例死亡）；相对风险[RR]为2.4；95%置信区间[CI]为1.6至3.4）。额外死亡率的主要原因是阻塞性肺疾病，即哮喘持续状态（14例死亡对0例死亡，RR 8.2）和未归类为哮喘持续状态的慢性阻塞性肺疾病（19例死亡对0例死亡，RR 8.3）。总体而言，哮喘队列中有91%的患者在近9年的平均随访期内存活，而对照组为96%。采用Cox多元回归模型进行的死亡率分析显示，年龄、吸烟包年数、嗜酸性粒细胞增多、预计第一秒用力呼气容积（FEV1）百分比水平以及FEV1的可逆程度是哮喘死亡的重要预测因素，而既往因哮喘住院与随后的哮喘死亡之间未发现关联。在嗜酸性粒细胞（>0.45×10⁹/L）的受试者中，死于哮喘的风险比无嗜酸性粒细胞增多的受试者高7.4倍（CI 2.8至19.7）。与FEV1可逆性为[15%至24%]的受试者相比，FEV1可逆性为[25%至49%]和>[50%]的受试者死于哮喘的风险分别高2.7倍和7.0倍。
与匹配的对照组相比，哮喘患者的死亡率显著增加，主要原因是急性和慢性哮喘死亡。此外，目前的研究结果表明，嗜酸性粒细胞增多和支气管扩张剂后FEV1的显著增加是随后死于哮喘风险的有力标志物。
