Smoking occurs frequently in patients with asthma. Recent surveys on smoking prevalence report 21-26% current smokers in populations of patients with asthma. Detrimental effects of active smoking in asthma include worse asthma control, an impaired response to corticosteroids and accelerated lung function decline.

Population

Stable asthmatic patients (however smokers, or non-smokers) will be included (stable asthmatic defined as no emergency clinic or hospital visit, oral corticosteroid prescription, or change in asthma treatment in the past month) and (Current smoking was defined as 5 or more cigarettes per day and a smoking history of 5 pack years or greater).

Brief Title

Interrelation Between Bronchial Asthma and Smoking

Official Title

Interrelation Between Bronchial Asthma and Smoking

Brief Summary

Smoking occurs frequently in patients with asthma. Recent surveys on smoking prevalence <br /> report 21-26% current smokers in populations of patients with asthma. Detrimental effects of <br /> active smoking in asthma include worse asthma control, an impaired response to <br /> corticosteroids and accelerated lung function decline.

Detailed Description

The mechanisms by which cigarette smoking contributes to disease severity in asthma are
incompletely understood, but it has been suggested that cigarette smoking may change
inflammation and airway remodelling in asthma to become more similar to that in COPD (chronic
obstructive pulmonary disease).

Any form of tobacco use, especially cigarette smoking, plays an important role in this
disease. Asthmatic smokers are prone to several negative outcomes. Cigarette smoking by
itself is associated with airway inflammation and features of airway remodelling including
increased epithelial proliferation, squamous cell metaplasia, goblet cell hyperplasia, smooth
muscle hypertrophy, and increases in bronchial glands mass.

Corticosteroid insensitivity is an important clinical feature of asthma, particularly in
patients with severe disease and smokers. The mechanisms of corticosteroid insensitivity in
asthmatic patients are poorly understood.

One of the major problems in the treatment of smoking asthma patients is the lack of efficacy
data in this group of patients as smokers have almost always been excluded from studies on
asthma due to perceived concerns about recruiting patients with COPD. Therefore, there is a
lack of specific information about the treatment of asthma in smokers. The asthmatic smoker
is a special phenotype with important therapeutic and prognostic clinical implications.

Outcome Measures

Outcome measures are the tests that investigators perform to prove whether or not a treatment being tested in a clinical trial is having any effect.

Inclusion criteria:

  1. Stable asthmatic patients (however smokers, or non-smokers) will be included (stable
     asthmatic defined as no emergency clinic or hospital visit, oral corticosteroid
     prescription, or change in asthma treatment in the past month) and (Current smoking
     was defined as 5 or more cigarettes per day and a smoking history of 5 pack years or
     greater).

  2. Treatment with long-acting b2-agonists, and leukotriene receptor antagonists was
     allowed.

Exclusion criteria:

  1. Acute severe asthma.

  2. Causes of airway obstruction other than asthma as COPD patients, bronchiectasis……etc.

  3. Age <18 and >45 years old.

  4. Body mass index >35.

  5. Requirement for treatment with or the presence of conditions likely to be exacerbated
     by oral corticosteroids

  6. The intention to stop smoking. Eligibility for the study required demonstration of
     reversible airflow obstruction (FEV1 bronchodilator response to b2 agonist of >12%
     [and >200 mL]) or a positive methacholine test result. All lung function assessments
     met relevant international consensus guidelines.