Childhood measles may cause postbronchodilator airflow obstruction in middle age
It appears that childhood measles infection contributes to postbronchodilator airflow obstruction (post-BD AO) through the associations between current clinical asthma and smoking in middle-aged adults, suggests a recent study.
“[W]e have found a novel interaction between the effects of childhood measles and the combination of current clinical asthma and smoking on a key diagnostic criterion for COPD [chronic obstructive pulmonary disease] in middle‐aged adults,” researchers said.
“While we did not find measles to have an independent effect on its own, our stratification has raised the possibility of a measles-related adult asthma phenotype that most likely originated in childhood,” they added.
A total of 950 (69 percent) participants had a history of childhood measles. Childhood measles appeared to compound the combined adverse effect of current asthma and smoking ≥10 pack-years on post-BD forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) in middle age (z score, –0.70; 95 percent CI, –1.1 to –0.3 vs –1.36; –1.6 to –1.1; three-way interaction: p=0.009), especially for those with childhood-onset asthma. [Respirology 2018;23:780-787]
Surprisingly, the increased odds for post-BD AO were not significant in the presence of childhood measles for never- and ever-smokers of <10 pack-years who had current asthma symptoms vs those without childhood measles (odds ratio, 12.0; 3.4–42 vs 2.17; 0.9–5.3).
“These findings, if replicated by others, may give rise to opportunities for ‘personalized prevention’, especially for developing countries which have high personal smoking rates and are home to the majority of the world's unvaccinated children,” researchers said. [www.who.int/mediacentre/factsheets/fs339/en/#; www.who.int/mediacentre/factsheets/fs286/en/]
Researchers have reported the concept of an interaction between asthma and smoking in relation to post-BD AO in their previous work, but the finding on modification by childhood measles is a novel one. [Am J Respir Crit Care Med 2013;187:42-48; Lancet 2015;385:1778-1788]
“The measles virus is highly contagious for all nonimmunized individuals who have not had the disease, and so was highly prevalent in this preimmunization era group, but we found no independent effect of measles on its own,” they said. [Lancet 1968;2:610-613]
From an epidemiological perspective, childhood measles is not sufficient to cause disease on its own, but together with other component causes it could contribute towards causing disease, according to researchers. [Am J Epidemiol 1976;104:5875-5892]
In the present study, the population-based Tasmanian Longitudinal Health Study cohort born in 1961 (n=8,583) underwent spirometry in 1968 before immunization was introduced. School medical records were used to obtain the history of childhood measles. A subgroup underwent further lung function measurements (n=1,389) during the fifth decade follow-up (n=5,729 responses).
Researchers used multiple regression to estimate relevant main associations and interactions by asthma and/or smoking on post-BD FEV1/FVC (continuous variable) and AO (FEV1/FVC < lower limit of normal).