The Role of Smoking in Allergy and Asthma: Lessons from the ECRHS.

Curr Allergy Asthma Rep. 2012 Apr 17;

Authors: Accordini S, Janson C, Svanes C, Jarvis D

Abstract
The European Community Respiratory Health Survey is an international multicenter cohort study of asthma, allergy, and lung function that began in the early-1990s with recruitment of population-based samples of 20- to 44-year-old adults, mainly in Europe. The aims of the study are broad ranging but include assessment of the role of in utero exposure to tobacco smoke, exposure to environmental tobacco smoke, and active smoking on the incidence, prevalence, and prognosis of allergy and asthma. Cross-sectional and longitudinal analyses looking at these associations have been conducted, sometimes only using information collected in one country, and on other occasions using information collected in all the participating centers. This article summarizes the results from these various publications from this large epidemiologic study.

PMID: 22528471 [PubMed - as supplied by publisher]

Asthma Severity, Exacerbation Risk, and Controller Treatment Burden in Underweight and Obese Children.

J Asthma. 2012 Apr 25;

Authors: Lang JE, Hossain J, Smith K, Lima JJ

Abstract
Objective. The relationship between weight status and asthma characteristics in children remains inadequately defined. Very little has been published on the risk of exacerbation, physician perception of severity, and the level controller treatment prescribed to underweight and obese children with asthma in a real-world setting. Methods. We assessed the diagnostic severity, pulmonary function, exacerbation prevalence, and controller treatment level in 10,559 new asthma patients seen at one of four pediatric asthma subspecialty clinics among three BMI groups. Participants were analyzed by body mass index (BMI)-percentile based on Centers for Disease Control & Prevention classification. Multivariable logistic regression models were used to assess the associations between BMI-percentile cohort group and asthma outcomes. Results. Underweight asthmatics were rare (2.5%) relative to obese asthmatics but appeared to have the greatest impairment in forced vital capacity and had the greatest controller treatment burden. Obese asthmatic children made up 26.2% of our cohort and were more likely to have severe disease (odds ratio (OR) 1.40, 95% confidence interval (CI) 1.06-1.85) and airflow obstruction (OR 1.36, 95% CI 1.16-1.59) compared to normal weight asthmatics. Obese asthmatics were not at greater risk for exacerbation (OR 1.41, 95% CI 0.64-3.11) or high treatment burden (OR 1.03, 95% CI 0.83-1.28). Conclusions. Obesity is more common than underweight status among children with asthma. Both underweight and obese children with asthma have worse lung function and asthma-related outcomes compared to similar normal weight children, though the phenotypic characteristics of underweight and obese asthmatics differed considerably.

PMID: 22530959 [PubMed - as supplied by publisher]

Although many guidelines recommend regular exercise for adults with asthma, the empirical evidence on the effect of exercise on adult asthma has been inconsistent and there are no previous systematic reviews on this topic. To fill in this gap of knowledge, we synthesized the data on the effects of regular exercise on physical fitness, asthma control and quality of life of adult asthmatics.

We performed a Medline search from 1980 through June 2011. In the systematic review we included all clinical trials that provided information on the effects of regular exercise on adult asthma. We conducted meta-analyses of maximal oxygen consumption (VO(2)max) and forced expiratory volume in 1 s (FEV(1)) based on 9 studies. A total of 11 studies were included in the analyses, but only 6 of them had a non-exercising reference group of asthmatics. The meta-analyses of randomized controlled trials showed that regular exercise significantly improved VO(2)max. There was no obvious improvement in lung function measurements. Some individual studies showed evidence of improvement in quality of life and asthma control.

Meta-analyses provided evidence that regular physical exercise improves physical fitness of adult asthmatics. The results on effects on lung function were inconclusive. There is insufficient evidence to assess the effects of exercise on asthma control and quality of life.

Vitamin D metabolites are important immune-modulatory hormones and are able to suppress Th2-mediated allergic airway disease. Some genetic factors that may contribute to asthma are regulated by vitamin D, such as vitamin D receptor (VDR), human leukocyte antigen genes (HLA), human Toll-like receptors (TLR), matrix metalloproteinases (MMPs), a disintegrin and metalloprotein-33 (ADAM-33), and poly(ADP-ribosyl) polymerase- 1 (PARP-1).

Vitamin D has also been implicated in asthma through its effects on the obesity, bacillus Calmettee Guérin (BCG) vaccination and high vitamin D level, vitamin D supplement, checkpoint protein kinase 1 (Chk1), plasminogen activator inhibitor-1 (PAI-1) and gamma delta T cells (gdT). Vitamin D plays a role in asthma and exerts its action through either genomic and/or non-genomic ways.