By Ves Dimov, MD
Allergist/Immunologist, Assistant Professor of Medicine and Pediatrics
University of Chicago
Posted: 12 October 2012
Obesity is associated with decreased airway inflammation in obese people with asthma
Obesity is a risk factor for asthma but the reasons for this are poorly understood. This study recruited a cohort of obese women with asthma and obese control women. They were followed for 12 months after bariatric surgery.
Obesity was associated with increased markers of inflammation in serum and adipose tissue and yet decreased airway inflammation in obese people with asthma; these patterns reversed with bariatric surgery. Leptin and other adipokines may be important mediators of airway disease in obesity through direct effects on the airway rather than by enhancing airway inflammation.
Sideleva O, Suratt BT, Black KE, Tharp WG, Pratley RE et al. Obesity and Asthma: an inflammatory disease of adipose tissue not the airway. American Journal of Respiratory and Critical Care Medicine 2012; 186(7): 598-605.
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Wheezing disorders in preschool children: an evidence-based approach
There is poor agreement on definitions of different phenotypes of preschool wheezing disorders. The European Respiratory Society (ERS) Task Force proposed to use of the following terms:
- episodic (viral) wheeze to describe children who wheeze intermittently and are well between episodes
- multiple-trigger wheeze for children who wheeze both during and outside discrete episodes
Allergen avoidance may be considered when sensitization has been established.
Maintenance treatment with inhaled corticosteroids is recommended for multiple-trigger wheeze; however, benefits are often small. Montelukast is recommended for the treatment of episodic (viral) wheeze and can be started when symptoms of a viral cold develop.
Given the large overlap in phenotypes, and the fact that patients can move from one phenotype to another, inhaled corticosteroids and montelukast may be considered on a trial basis in a preschool child with recurrent wheeze, but should be discontinued if there is no clear clinical benefit.
Large well-designed randomized controlled trials with clear descriptions of patients are needed to improve the present recommendations.
Brand PLP, Baraldi E, Bisgaard H, Boner AL, Castro-Rodriguez JA et al. Definition, assessment and treatment of wheezing disorders in preschool children: an evidence-based approach. European Respiratory Journal 2008; 32(4): 1096-1110.
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Sputum inflammatory phenotypes are not stable in children with asthma
Two distinct, stable inflammatory phenotypes have been described in adults with asthma: eosinophilic and non-eosinophilic. This study evaluated sputum cytology in 51 children with severe asthma and 28 with mild to moderate asthma who were followed over 3 to 6 months.
78% of the children had increased levels of inflammatory cells in at least one sputum sample. In the longitudinal analysis, 63% of children demonstrated two or more phenotypes. Change in phenotype was not related to change in inhaled corticosteroid (ICS) dose or asthma control, nor was it reflected in a change in exhaled nitric oxide (FENO). Remarkably, 41% of children fulfilled the criteria for non-eosinophilic asthma on one occasion and eosinophilic on another. There were no differences in severity, asthma control, atopy, ICS dose or FEV1 between those who were always non-eosinophilic and those always eosinophilic.
The authors concluded that sputum inflammatory phenotypes are not stable in children with asthma.
Fleming L, Tsartsali L, Wilson N, Regamey N, Bush A. Sputum inflammatory phenotypes are not stable in children with asthma. Thorax 2012; 67(8):675-681.
Posted: 12 October 2012