Positive Exercise Test and Obstructive Spirometry in Young Male Conscripts Associated with Persistent Asthma 20 years Later

Abstract

Background. Asthma often begins in childhood or early adulthood and is a common disease among conscripts. The identification of long-term predictive factors for persistent asthma may lead to improved treatment opportunities and better disease control. Objective. Our aim was to study the prognostic factors of the severity of asthma among 40-year-old male conscripts whose asthma began in youth. Methods. We studied 119 conscripts who were referred to the Central Military Hospital during 1987–1990 due to asthma and who attended a follow-up visit approximately 20 years later. Asthma severity was evaluated during military service according to the medical records, and 20 years later during a follow-up visit using Global Initiative for Asthma guidelines. We used the results of lung function and allergy tests at baseline as predictors of current persistent asthma. Results. Compared with baseline, asthma was less severe at follow-up: 11.8% of subjects were in remission, 42.0% had intermittent asthma, 10.9% had mild persistent asthma, and 35.3% had moderate/severe persistent asthma (p < .001). In multivariate models, a positive exercise test at baseline yielded an odds ratio (OR) of 3.2 (95% CI 1.0–9.8, p = .046), a decreased FEV₁/FVC % predicted an OR of 4.0 (95% CI 1.7–9.3, p = .002), and a decreased FEF_50% % predicted an OR of 2.8 (95% CI 1.3–6.4, p = .012) for current persistent asthma. Conclusions. About half of the men had persistent asthma at the 20-year follow-up. Positive exercise tests and obstructive spirometry results were related to the persistence of asthma and may be useful long-term prognostic factors for asthma severity.

• asthma
• epidemiology
• exercise test
• forced expiratory flow rate at 50% of vital capacity
• prognostic factors
• spirometry

Acknowledgments

The authors thank Outi Fisher and the study nurses.

Declaration of Interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. This study was supported by the The Finnish Work Environment Fund, Finnish Defence Forces, and Ida Montin Foundation.