What Is New In Small Airways Research
By Ves Dimov, MD
Assistant Professor of Medicine and Pediatrics
University of Chicago
The purpose of this meta-analysis (6 RTCs) was to estimate the risk of asthma exacerbation in stable asthmatics who reduce inhaled corticosteroids (ICS) compared to those who maintain a stable ICS dose.
The relative risk of an asthma exacerbation in individuals who reduced ICS compared to those who maintained the same ICS dose was 1.25 in studies with a mean follow-up of 22 weeks (5.5 months). Individuals who reduced ICS had a decreased% predicted FEV1 of 0.87% and a decreased mean morning peak expiratory flow of 9.57 l/min compared to those individuals who maintained a stable ICS dose.
Asthma exacerbations were statistically no more likely among individuals who reduced ICS compared to those who maintained their ICS dose, supporting current guidelines which recommend decreasing ICS by 50% after a period of asthma stability.
Source: Hagan JB, Samant SA, Volcheck GW, Li JT, Hagan CR, Erwin PJ, Rank MA. The risk of asthma exacerbation after reducing inhaled corticosteroids: a systematic review and meta-analysis of randomized controlled trials. Allergy 2014; 69(4):510-516. (doi:10.1111/all.12368).
Image Source: From “Section 4, Stepwise Approach for Managing Asthma in Youths ≥12 Years of Age and Adult”, in Expert Panel Report 3: Guidelines for the Diagnosis and Management of Asthma. National Asthma Education and Prevention Program, Third Expert Panel on the Diagnosis and Manage of Asthma, Bethesda (MD): National Heart, Lung, and Blood Institute: 2007 Aug, NCBI Bookshelf ID: NBK7222, public domain.
Asthma in pregnancy: a hit for two (2014 full text review)
Asthma is common in pregnant women and there are well-known risks particularly among females with moderate-to-severe asthma and exacerbations during pregnancy:
- low birth weight and small for gestational age
- preterm birth, especially with oral steroid use
- a small but statistically significant increased risk of congenital malformations, particularly of cleft lip with or without cleft palate
- an increased risk of neonatal hospitalization and death
Active management may reduce these risks, possibly through reductions in exacerbations.
Viral infections are an important trigger of asthma exacerbations in pregnancy. In the vast majority of cases, benefits outweigh the risks of indicated asthma medication use in pregnancy. Poor medication adherence despite worsening asthma symptoms in pregnancy is a problem.
Improving asthma control in pregnancy has the potential to improve not only the mother’s health but also that of her child.
Source: Murphy VE and Schatz M. Asthma in pregnancy: a hit for two. European Respiratory Review 2014; 23(131): 64-68.
Children with severe asthma have 32 times higher risk for developing COPD
The aim of this longitudinal, prospective study was to evaluate for an association between childhood asthma and adult COPD.
The study included 6- to 7-year-old children who have been evaluated every 7 years to the current analysis at 50 years of age (197 patients). Participants completed respiratory questionnaires and lung function spirometry with postbronchodilator response.
At the age of 50, patients were classified to the following subgroups: non-asthmatics, asthma remission, current asthma and COPD. COPD was defined by FEV1 to FVC ratio postbronchodilator of less than 0.7.
As compared with children without symptoms of wheeze to the age of 7, (non-asthmatics) children with severe asthma had an adjusted 32 times higher risk for developing COPD. Of note, 43% of the COPD group had never smoked.
There was no evidence of a difference in the rate of decline in FEV1 between the COPD group (17 mL/year) and the other groups.
Source: Tai A, Tran H, Roberts M, Clark N, Wilson J, Robertson C. The association between childhood asthma and adult chronic obstructive pulmonary disease. Thorax 2014. (doi:10.1136/thoraxjnl-2013-204815)