Natural history of chronic asthma and its long-term effects on pulmonary function

Self-Efficacy Intervention Programs in Patients with Chronic Obstructive Pulmonary Disease: Narrative Review

Chronic obstructive pulmonary disease (COPD) is a common chronic disease whose development is irreversible, which leads to more than six million deaths each year. There is no treatment confirmed effective for the improvement of impaired lung function, but the combination of drug therapy with non-drug therapy such as pulmonary rehabilitation training has demonstrated a great potential in reducing the occurrence of complications and delaying the progression of COPD. Self-efficacy is the core of cognitive theory, which is crucial for chronic disease management. It has been proposed as an important component of disease management to help people develop skills to manage diseases more effectively. This study reviewed the development of self-efficacy and its application in patients with COPD, with the purpose of providing a better clinical reference for the treatments of COPD.

Asthma in Children and Adults-What Are the Differences and What Can They Tell us About Asthma?

Asthma varies considerably across the life course. Childhood asthma is known for its overall high prevalence with a male predominance prior to puberty, common remission, and rare mortality. Adult asthma is known for its female predominance, uncommon remission, and unusual mortality. Both childhood and adult asthma have variable presentations, which are described herein. Childhood asthma severity is associated with duration of asthma symptoms, medication use, lung function, low socioeconomic status, racial/ethnic minorities, and a neutrophilic phenotype. Adult asthma severity is associated with increased IgE, elevated FeNO, eosinophilia, obesity, smoking, and low socioeconomic status. Adult onset disease is associated with more respiratory symptoms and asthma medication use despite higher prebronchodilator FEV1/FVC. There is less quiescent disease in adult onset asthma and it appears to be less stable than childhood-onset disease with more relapses and less remissions.

Improving the differential diagnosis of chronic obstructive pulmonary disease in primary care

Chronic obstructive pulmonary disease (COPD) and asthma represent a substantial portion of primary care practice. In adults, differentiating asthma from COPD can be difficult but is important because of the marked differences in treatment, disease progression, and outcomes between the 2 conditions. Currently, clinical COPD is often misdiagnosed or undiagnosed until late in the disease. Earlier diagnosis could markedly reduce morbidity and improve quality of life. Establishing a diagnosis of COPD requires spirometry testing, interpreted in the context of the patient's symptoms, smoking status, age, and comorbidities. Additional tests and tools may be helpful in the differential diagnosis, including questionnaires specifically developed to discriminate between COPD and asthma and, in special cases, imaging studies. Follow-up and monitoring of asthma and COPD are always necessary and provide additional benefit in patients in whom only continued care and reassessment can confirm the final diagnosis, such as younger individuals with fixed airway obstruction, smokers with asthma, and patients with both disorders. Key areas for improvement include enhanced case identification, improved quality and interpretation of findings on spirometry, and increased use of tools such as differential diagnosis questionnaires and algorithms to guide the diagnostic and monitoring process. To achieve optimal outcomes, the primary care team should make every effort to establish a firm diagnosis. For this review, we conducted a PubMed search with no time limits using the Medical Subject Headings chronic obstructive pulmonary disease or COPD and asthma, in association with the following search terms: diagnosis, differential diagnosis, mixed or comorbid disease, diagnostic techniques, spirometry, questionnaires, and primary care.

Long-term deterioration of lung function in asthmatic outpatients

BACKGROUND

Although the long-term deterioration of lung function in asthmatic patients has been described, the exact mechanism remains to be determined.

OBJECTIVES

The aim of this study was to find correlations between age, sex, atopic status, duration of asthma, asthma severity and the decline in pulmonary function.

METHOD

The medical histories of 1,006 randomly chosen asthmatic outpatients were studied and retrospective data on asthma duration, spirometry results, treatment and symptomatology were gathered. A screening spirometry was performed.

RESULTS

598 women and 408 men (age: 44.59, range 12-95 years) participated in the study. Intermittent asthma was diagnosed in 35.4%, chronic mild asthma in 33.4%, moderate asthma in 23.8% and severe asthma in 7.45% of the patients. Statistically significant correlations between patient age, asthma duration and lung function measurements were found. Linear regression revealed the following differences in lung functions per year of asthma duration: FEV1: -0.882% of predicted; FVC: -0.509% of predicted; FEV1/FVC: -0.324% of predicted. The unadjusted annual decline was 80.1 ml/year (p = 0.00003) in FEV1 and 20.5 ml/year (p = 0.036) in FVC. A multiple regression model revealed that asthma severity appears to be the strongest factor influencing pulmonary function (beta = -0.55, p < 0.001 for FEV1). Also, significant associations between pulmonary function measurements, patient age, atopic status and male sex were noted.

CONCLUSIONS

The results of this large cohort study show that asthmatic patients develop a progressive decline in pulmonary function correlated with age, sex, duration of asthma and asthma severity. Early diagnosis and intervention is necessary to ameliorate any potential negative impact of asthma on lung function.

Anti-inflammatory treatment for recurrent wheezing in the first five years of life

Medications identified for the treatment of recurrent wheezing in preschool children by the Expert Panel Report of the NHLBI Guidelines for the Diagnosis and Management of Asthma include inhaled corticosteroids, chromones, theophylline, and leukotriene pathway modifiers. However, these various agents differ in their mechanism, extent of action on the airway inflammatory process, and degree of clinical efficacy. Inhaled corticosteroids can control symptoms in many young children with even severe persistent wheezing, but data on their long-term safety when administered in preschool-age children are scarce. There is some information on the uninterrupted use of inhaled corticosteroids in school-age children and the absence of an adverse effect on ultimate adult height. Despite laboratory evidence of adrenal suppression in some studies, few pediatric cases of clinical adrenal insufficiency have been reported. Low-dose inhaled corticosteroid (<400 mcg/day for beclomethasone), which is adequate for controlling mild persistent symptoms, is generally safe. Chromones have a remarkable safety profile, but they are most effective for symptoms of mild severity. Promising data have been published on the efficacy and safety of leukotriene pathway modifiers when used in young children with persistent symptoms. It is uncertain whether early introduction and long-term administration of inhaled corticosteroids prevent development of irreversible airway obstruction. Nevertheless, they may be especially useful for patients with moderate to severe disease in whom other agents (chromones or leukotriene pathway modifiers) will most likely fail to control symptoms. Pediatr Pulmonol. 2003; 35:241-252.

The early course of newly diagnosed asthma

PURPOSE

We describe the intensity of therapy for patients with newly diagnosed asthma and how it changed during subsequent years in relation to age, sex, and initial level of therapy.

METHODS

We examined a cohort of 13,671 patients in Saskatchewan, Canada, who were initially between the ages of 5 and 44 years. Patients were followed prospectively, and the intensity of asthma therapy was measured during successive 12-month periods.

RESULTS

Based on the intensity of asthma drug therapy during the first year after entry into the cohort, 6661 patients (48.7%) were initially prescribed therapy judged to be appropriate for mild asthma, and 977 (7.1%) were dispensed medications in a manner suggesting their asthma was severe; the remaining 6033 (44.1%) were classified as receiving treatment of intermediate intensity. Among patients initially classified as receiving treatment appropriate for mild disease, only about 3% were dispensed medications that suggested that their asthma had become severe during up to 5 years of follow-up. Intensity of therapy waned in a substantial proportion of patients who were initially classified as having severe asthma, especially if they were initially younger than 15 years of age. Thirty-four per 100 patients initially younger than 15 years old were receiving medications appropriate for mild asthma, and 23 per 100 such patients received no medication for asthma during a 12-month period when followed up to 5 years.

CONCLUSION

Patients with asthma who are initially treated with therapy appropriate for mild asthma are rarely treated later with therapy suggesting the advent of severe disease. Patients initially dispensed medications suggesting the presence of severe asthma often see the intensity of treatment wane over time.

Factors associated with persistent airflow limitation in severe asthma

Persistent airflow limitation can develop in nonsmoking patients with asthma. However, the prevalence and risk factors for airways obstruction with incomplete reversibility in asthma are unknown. We assessed the prevalence of persistent airflow limitation (defined as postbronchodilator FEV(1) or FEV(1)/VC < 75% predicted) in 132 nonsmoking outpatients with severe asthma visiting chest physicians in general hospitals in The Netherlands. They had used inhaled corticosteroids (> or = 1,600 microg/d) and/or daily oral prednisone and long-acting bronchodilators for > 1 yr. In addition, we examined whether persistent airways obstruction in these patients was associated with specific clinical characteristics (age at onset, smoking history, atopic status, bronchodilator reversibility, provocative concentration of histamine causing a 20% decrease in FEV(1) [PC(20)histamine]) or markers of inflammation (exhaled nitric oxide [NO], blood eosinophils, total IgE; and eosinophilia or neutrophilia in induced sputum). Multiple logistic regression analyses were used to calculate adjusted odds ratios (OR). Persistent airflow limitation was observed in 49% of the patients in the study, and apart from older age and longer asthma duration, was strongly associated with a sputum eosinophils percent > or = 2% (OR = 7.7; confidence interval [CI]: 2.4 to 25), PC(20)histamine < or = 1.0 mg/ml (OR = 3.9; CI: 1.2 to 13), and adult onset (> or = 18 yr) of asthma (OR = 3.3; CI: 1.2 to 9). Only sputum eosinophilia appeared to be independently associated with persistent airflow limitation (OR = 8.9; CI: 1.3 to 59). In conclusion, persistent airflow limitation is common in adult patients with severe asthma, and is associated with adult onset of the disease, airway hyperresponsiveness, and most importantly, sputum eosinophilia. These findings suggest that eosinophilic airway inflammation contributes to persistent airflow limitation in severe asthma. Whether reduction of sputum eosinophils with more vigorous treatment leads to a better prognosis in severe asthma is still an open question.