Ambient ozone and asthma hospital admissions in Texas: a time-series analysis
Many studies have evaluated associations between asthma emergency department (ED) visits, hospital admissions (HAs), and ambient ozone (O3) across the US, but not in Texas. We investigated the relationship between O3 and asthma HAs, and the potential impacts of outdoor pollen, respiratory infection HAs, and the start of the school year in Texas.
We obtained daily time-series data on asthma HAs and ambient O3 concentrations for Dallas, Houston, and Austin, Texas for the years 2003–2011. Relative risks (RRs) and 95% confidence intervals (CIs) of asthma HAs per 10-ppb increase in 8-h maximum O3 concentrations were estimated from Poisson generalized additive models and adjusted for temporal trends, meteorological factors, pollen, respiratory infection HAs, day of the week, and public holidays. We conducted a number of sensitivity analyses to assess model specification.
We observed weak associations between total asthma HAs and O3 at lags of 1 day (RR10 ppb = 1.012, 95% CI: 1.004–1.021), 2 days (RR10 ppb = 1.011, 95% CI: 1.002–1.019), and 0–3 days (RR10 ppb = 1.017, 95% CI: 1.005–1.030). The associations were primarily observed in children aged 5–14 years (e.g., for O3 at lag 0–3 days, RR10 ppb = 1.037, 95% CI: 1.011–1.064), and null in individuals 15 years or older. The effect estimates did not change significantly with adjustment for pollen and respiratory infections, but they attenuated considerably and lost statistical significance when August and September data were excluded. A significant interaction between time around the start of the school year and O3 at lag 2 day was observed, with the associations with pediatric asthma HAs stronger in August and September (RR10 ppb = 1.040, 95% CI: 1.012–1.069) than in the rest of the year (October–July) (RR10 ppb = 1.006, 95% CI: 0.986–1.026).
We observed small but statistically significant positive associations between total and pediatric asthma HAs and short-term O3 exposure in Texas, especially in August and September. Further research is needed to determine how the start of school could modify the observed association between O3 and pediatric asthma HAs.
Associations between serum 25(OH)D concentrations and prevalent asthma among children living in communities with differing levels of urbanization: a cross-sectional study
Prior evidence suggests that vitamin D deficiency may increase the risk of asthma and atopy and impair pulmonary function in children.
In this cross-sectional analysis nested in a case-control study, we analyzed serum 25(OH)D concentrations in 413 children with asthma and 471 children without asthma living in two geographically adjacent study communities (Pampas and Villa El Salvador). We measured total and antigen-specific IgE levels, pulmonary function, asthma control, and exhaled nitric oxide.
Mean 25(OH)D concentrations were 25.2 ng/mL (SD 10.1) in children with asthma and 26.1 ng/mL (SD 13.7) in children without asthma (p = 0.28). Vitamin D deficiency (25(OH)D < 20 ng/ml) was more common in Pampas than in Villa El Salvador (52.7% vs. 10.5%; p < 0.001). In the overall study population, a 10 ng/ml decrease in serum 25(OH)D concentrations was not significantly associated with odds of asthma (OR 1.09, 95% CI: 0.94 to 1.25). However, vitamin D deficiency was associated with a 1.6-fold increase in odds of asthma in the overall cohort (95% CI: 1.14 to 2.25). After stratifying by site, a 10 ng/mL decrease in serum 25(OH)D concentrations was associated with 18% higher odds of having asthma in Pampas (OR = 1.18, 95% CI 1.02 to 1.38), whereas there was no significant association between 25(OH)D concentrations and asthma in Villa El Salvador (OR = 0.95, 95% CI 0.87 to 1.05). Combined data from these geographically adjacent populations suggests a possible threshold for the relationship between 25(OH)D levels and asthma at approximately 27.5 ng/ml. Serum 25(OH)D concentrations were not clearly associated with asthma control, total serum IgE, atopy, or airway inflammation.
Serum 25(OH)D concentrations were inversely associated with asthma in one study community with a high prevalence of deficiency. Studies are needed to investigate a possible threshold 25(OH)D concentration after which higher vitamin D levels show no further benefit for asthma.
Asthma: epidemiology of disease control in Latin America – short review
Asthma is reported as one of the most common chronic diseases in childhood, impairing the quality of life of patients and their families and incurring high costs to the healthcare system and society. Despite the development of new drugs and the availability of international treatment guidelines, asthma is still poorly controlled, especially in Latin America. Original and review articles on asthma control or epidemiology with high levels of evidence have been selected for analysis among those published in PubMed referenced journals during the last 20 years, using the following keywords: “asthma control” combined with “Latin America”, ” epidemiology”, “prevalence”, “burden”, “mortality”, “treatment and unmet needs”, “children”, “adolescents”, and “infants”. There was a high prevalence and severity of asthma during the period analyzed, especially in children and adolescents. Wheezing in infants was a significant reason for seeking medical care in Latin American health centers. Moreover, the frequent use of quick-relief bronchodilators and oral corticosteroids by these patients indicates the lack of a policy for providing better care for asthmatic patients, as well as poor asthma control. Among adults, studies document poor treatment and control of the disease, as revealed by low adherence to routine anti-inflammatory medications and high rates of emergency care visits and hospitalization. In conclusion, although rare, studies on asthma control in Latin America repeatedly show that patients are inadequately controlled and frequently overestimate their degree of asthma control according to the criteria used by international asthma treatment guidelines. Additional education for doctors and patients is essential for adequate control of this illness, and therefore also for reduction of the individual and social burden of asthma.
Asthma in the elderly: a double-blind, placebo-controlled study of the effect of montelukast
Published: 17 April 2017
Little is known about asthma in the elderly as most studies of this condition have not included this patient group. It is unclear whether leukotriene antagonists benefit older asthmatics. We studied the effect of adding montelukast to the asthma treatment of elderly subjects.
Twenty-five subjects 65 years old and older with asthma were evaluated at week 0, 1, 5, 9, 13, and 17. Each subject received montelukast 10 mg and placebo each for 8 weeks in a cross-over design.
Montelukast for 4 or 8 weeks did not significantly affect ACT, daily symptom scores, number of puffs of albuterol, spirometric values, peripheral blood eosinophils, or serum IgE vs. baseline or placebo. Similar results were obtained when analyzing subgroups of patients with lower ACT, lower FEV1, and higher eosinophils.
In this study of elderly asthmatics, montelukast had no effect on asthma symptoms, number of puffs of albuterol, spirometric values, peripheral blood eosinophils or serum IgE. These results will require confirmation in larger patient cohorts and in patients with uncontrolled asthmatic symptoms.
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Gender-specific determinants of asthma among U.S. adults
Asthma, a chronic respiratory disease affecting over 18.7 million American adults, has marked disparities by gender, race/ethnicity and socioeconomic status. Our goal was to identify gender-specific demographic and socioeconomic determinants of asthma prevalence among U.S. adults using data from the Behavioral Risk Factors Surveillance System (BRFSS) and the National Health and Nutrition Examination Survey (NHANES).
Gender-specific regression analyses were performed to model the relationship between asthma prevalence with age, race/ethnicity, income, education level, smoking status, and body mass index (BMI), while taking into account the study designs.
Based on BRFSS data from 1,003,894 respondents, weighted asthma prevalence was 6.2% in males and 10.6% in females. Asthma prevalence among grade 2 obese and grade 3 obese vs. not overweight or obese women was 2.5 and 3.5 times higher, respectively, while that in men was 1.7 and 2.4 times higher; asthma prevalence among current vs. never smoker women was 1.4 times higher, while that in men was 1.1 times higher. Similar results were obtained with NHANES data from 13,364 respondents: asthma prevalence among grade 2 obese and grade 3 obese vs. not overweight or obese respondents was 2.0 and 3.3 times higher for women, though there was no significant difference for men; asthma prevalence among current vs. never smokers was 1.8 times higher for women and not significantly different in men. Asthma prevalence by race/ethnicity and income levels did not differ considerably between men and women.
Our results underscore the importance of obesity and smoking as modifiable asthma risk factors that most strongly affect women.
Asthma costs and social impact
In recent decades, both asthma prevalence and incidence have been increasing worldwide, not only due to the genetic background, but mainly because of the effect of a wide number of environmental and lifestyle risk factors.
In many countries noncommunicable diseases, like asthma, are not yet considered a healthcare priority. This review will analyze and discuss disparities in asthma management in several countries and regions, such as access to healthcare human resources and medications, due to limited financial capacity to develop strategies to control and prevent this chronic disease.
This review tries to explore the social and economic burden of asthma impact on society. Although asthma is generally accepted as a costly illness, the total costs to society (direct, indirect and intangible asthma costs) are difficult to estimate, mainly due to different disease definitions and characterizations but also to the use of different methodologies to assess the asthma socio-economic impact in different societies.
The asthma costs are very variables from country to country, however we can estimate that a mean cost per patient per year, including all asthmatics (intermittent, mild, moderate and severe asthma) in Europe is $USD 1,900, which seems lower than USA, estimated mean $USD 3,100.
Preacutionary labelling of cross-reactive foods: The case of rapeseed
Alessandro Fiocchi, Lamia Dahdah, Carla Riccardi, Oscar Mazzina and Vincenzo Fierro
Food allergic individuals are exposed to unnecessary dietary restrictions due to precautionary food allergy labelling (PFAL). Two forms of PFAL exist: type I identifies the possible presence of allergenic contaminaion in foods (‘may content…’), type II indicates as potentially dangerous ingredients or contaminants that do no belong to official list of food allergens. PFAL type II is based on the fear of cross-reactivity with foods belonging to that list. PFAL type II is less known, but may be tempting for the legal offices of food companies, for clinicians in a ‘defensive medicine’ key, and even for legislators. We identify here a case of PFAL type II, allergy to rapeseed (belonging to the family of Brassicaceae). Increasingly used for their nutritional and nutraceutic value in asthma prevention, rapeseed has been indicated by regulatory authorities in Canada and Europe as potential cross-reactor with mustard. In this review, we provide the elements for a risk assessment of cross-reactivity of rapeseed/mustard allergy in the general population both clinically and from the point of view of the molecular allergy. Three findings emerge:
1. Allergic reactions to rapeseed are exceptional
2. The allergens identified in rapeseed and mustard are similar, but not identical
3. Reactions to rapeseed have never been described in mustard-allergic patients.
On the ground of existing evidence, a precautionary labeling for rapeseed as potentially dangerous for patients allergic to mustard is not justified. In the interest of patients with multiple food allergy, PFAL type II must be avoided.