Study results show that the majority of adult-onset asthma patients had uncontrolled or poorly controlled asthma. A separate study found that exposure to bleach in the home increased the risk of non-allergic adult-onset asthma in women.
The long-term prognosis of adult-onset asthma has remained unclear because of a lack of follow-up studies that included smokers. To clarify the prognosis of adult-onset asthma and the factors associated with this prognosis, the Seinäjoki Adult-onset Asthma Study (SAAS), a 12-year, Finnish single-center follow-up study, enrolled 203 patients with new-onset asthma diagnosed during adulthood and treated in primary and specialty care. Results of this study were recently reported in Respiratory Medicine.
The SAAS investigators reported that two-thirds (66%, or 134) of the specialist-diagnosed adult-onset asthma patients they studied had uncontrolled or poorly controlled asthma according to Global Initiative for Asthma 2010 definitions after 12 years of follow-up. Moreover, only 3% (6) of the SAAS study group reported asthma remission 12 years after diagnosis. Remission was defined as the absence of asthma symptoms and no asthma medication use for 6 months.
In addition, the SAAS investigators used multinomial multivariate logistic regression to analyze factors associated with current asthma control. This analysis determined that elevated blood eosinophils and good lung function (as assessed by forced expiratory volume in 1 second) at baseline protected patients from uncontrolled asthma.
In contrast, the following factors were identified as predictors of uncontrolled asthma:
Gender, age at asthma onset, and baseline symptoms as assessed by the Airways Questionnaire 20 did not predict uncontrolled asthma in SAAS patients.
Results of another study published in Respiratory Medicine found that the use of bleach in home cleaning was associated with increased risk of non-allergic adult-onset asthma in women.
Although the adverse respiratory health effects of the occupational use of this cleaning product have been recognized, whether common domestic use of bleach poses a risk of asthma has remained unclear.
To assess whether domestic use of bleach for home cleaning is associated with asthma and other adverse respiratory outcomes, a team of Parisian researchers analyzed data from skin prick tests, bronchial responsiveness challenge, and white blood cells in 607 women who participated in the follow-up phase of the Epidemiological Study on the Genetics and Environment of Asthma (EGEA). Information on the respiratory symptoms and cleaning habits of these women was obtained by questionnaire. Bleach use was categorized as less than 1 day/week, 1—2 days/week, and 4–7 days/week, or frequent.
Frequent bleach users were more likely to have current asthma than non-users [adjusted odds ratio (AOR) = 1.7; 95% confidence interval (CI), 1.0—3.0], and bleach use was associated with non-allergic asthma (AOR = 3.3; CI 1.5–7.1), particularly the adult-onset type (AOR = 4.9; CI, 2.0–11.6). In asthmatic women, frequent use of bleach was associated with higher blood neutrophil counts to a statistically significant degree. And among women without allergic sensitization, significant positive associations were consistently found between use of bleach and bronchial hyperresponsiveness, asthma-like symptoms, and chronic cough.
Based on these findings, the Parisian team concluded that frequent use of bleach for home cleaning is associated with non-allergic adult-onset asthma, elevated neutrophil counts, and lower-airway symptoms in women. As a result, they stressed that clinicians need to consider exposure to bleach as a precipitating or worsening factor in women with non-allergic asthma.