Environmental management of asthma in clinical practice: Results from the 2012 National Ambulatory Medical Care Survey.

Background: The National Asthma Education and Prevention Program guidelines emphasize environmental control as an integral part of asthma management; however, limited national-level data exist on how clinicians implement environmental control recommendations. Objective: We analyzed data on clinicians' self-reported use of recommended environmental control practices in a nationally representative sample (n = 1645) of primary care physicians, asthma specialists, and advanced practice providers from the National Asthma Survey of Physicians, a supplemental questionnaire to the 2012 National Ambulatory Medical Care Survey. Methods: We examined clinician and practice characteristics as well as clinicians' decisions and strategies regarding environmental trigger assessment and environmental control across provider groups. Regression modeling was used to identify clinician and practice characteristics associated with implementation of guideline recommendations. Results: A higher percentage of specialists assessed asthma triggers at home, school, and/or work than primary care or advanced practice providers (almost always: 53.6% vs 29.4% and 23.7%, respectively, P < .001). Almost all clinicians (>93%) recommended avoidance of secondhand tobacco smoke, whereas recommendations regarding cooking appliances (eg, proper ventilation) were infrequent. Although assessment and recommendation practices differed between clinician groups, modeling results showed that clinicians who reported almost always assessing asthma control were 5- to 6-fold more likely to assess environmental asthma triggers. Use of asthma action plans was also strongly associated with implementation of environmental control recommendations. Conclusions: Environmental assessment and recommendations to patients varied among asthma care providers. High adherence to other key guideline components, such as assessing asthma control, was associated with environmental assessment and recommendation practices on environmental control.

Randomized Clinical Trial of Air Cleaners to Improve Indoor Air Quality and Chronic Obstructive Pulmonary Disease Health: Results of the CLEAN AIR Study.

Rationale: Indoor particulate matter is associated with worse chronic obstructive pulmonary disease (COPD) outcomes. It remains unknown whether reductions of indoor pollutants improve respiratory morbidity. Objectives: To determine whether placement of active portable high-efficiency particulate air cleaners can improve respiratory morbidity in former smokers. Methods: Eligible former smokers with moderate-to-severe COPD received active or sham portable high-efficiency particulate absolute air cleaners and were followed for 6 months in this blinded randomized controlled trial. The primary outcome was 6-month change in St. George's Respiratory Questionnaire (SGRQ). Secondary outcomes were exacerbation risk, respiratory symptoms, rescue medication use, and 6-minute-walk distance (6MWD). Intention-to-treat analysis included all subjects, and per-protocol analysis included adherent participants (greater than 80% use of air cleaner). Measurements and Main Results: A total of 116 participants were randomized, of which 84.5% completed the study. There was no statistically significant difference in total SGRQ score, but the active filter group had greater reduction in SGRQ symptom subscale (ß, -7.7 [95% confidence interval (CI), -15.0 to -0.37]) and respiratory symptoms (Breathlessness, Cough, and Sputum Scale, ß, -0.8 [95% CI, -1.5 to -0.1]); and lower rate of moderate exacerbations (incidence rate ratio, 0.32 [95% CI, 0.12-0.91]) and rescue medication use (incidence rate ratio, 0.54 [95% CI, 0.33-0.86]) compared with sham group (all P < 0.05). In per-protocol analysis, there was a statistically significant difference in primary outcome between the active filter versus sham group (SGRQ, ß -4.76 [95% CI, -9.2 to -0.34]) and in moderate exacerbation risk, Breathlessness, Cough, and Sputum Scale, and 6MWD. Participants spending more time indoors were more likely to have treatment benefit. Conclusions: This is the first environmental intervention study conducted among former smokers with COPD showing potential health benefits of portable high-efficiency particulate absolute air cleaners, particularly among those with greater adherence and spending a greater time indoors.

Home Dust Allergen Exposure Is Associated with Outcomes among Sensitized Individuals with Chronic Obstructive Pulmonary Disease.

Rationale: Environmental exposures have been associated with adverse outcomes in chronic obstructive pulmonary disease (COPD). Approximately one-third of individuals with COPD have allergic sensitization, but it is unknown whether exposure to allergens in the home is associated with outcomes. Objectives: To determine the prevalence and associations of allergen sensitization with exposure to common indoor allergens with symptoms and exacerbation risk in COPD. Methods: Allergen sensitization to five common indoor allergens was assessed in former smokers with COPD. Home settled dust was assessed for presence of corresponding allergens. Sensitization and exposure status was determined and associations evaluated in adjusted models with longitudinal outcomes including symptoms, lung function, and exacerbations. Interactions were assessed between sensitization/exposure status and lung function. Measurements and Main Results: One hundred eighty-three individuals studied were on average 67.3 years of age (SD, 8.22) with average FEV1 of 53.2% (SD, 17.6%). Seventy-seven percent of participants were exposed to at least one tested allergen, and 17% had sensitization with corresponding allergen exposure. After adjustment, sensitization with exposure was associated with lower lung function (ß, -8.29; 95% confidence interval [CI], -14.80 to -1.77), higher St. George's Respiratory Questionnaire Total Score (ß, 6.71; 95% CI, 0.17 to 13.25), and higher exacerbation risk (odds ratio, 2.31; 95% CI, 1.11 to 4.79). Associations appeared to be more pronounced among individuals with lower lung function. Conclusions: Allergen exposures are common in COPD and associated with adverse outcomes among those with concomitant allergen sensitization. This study establishes allergens as an important home exposure that potentially could be addressed with comprehensive home environmental modification strategies to improve COPD outcomes.

Clinical Phenotypes of Atopy and Asthma in COPD: A Meta-analysis of SPIROMICS and COPDGene.

BACKGROUND: Little is known about the concordance of atopy with asthma COPD overlap. Among individuals with COPD, a better understanding of the phenotypes characterized by asthma overlap and atopy is needed to better target therapies. RESEARCH QUESTION: What is the overlap between atopy and asthma status among individuals with COPD, and how are categories defined by the presence of atopy and asthma status associated with clinical and radiologic phenotypes and outcomes in the Genetic Epidemiology of COPD Study (COPDGene) and Subpopulation and Intermediate Outcome Measures in COPD Study (SPIROMICS)? STUDY DESIGN AND METHODS: Four hundred three individuals with COPD from SPIROMICS and 696 individuals from COPDGene with data about specific IgEs to 10 common allergens and mixes (simultaneous assessment of combination of allergens in similar category) were included. Comparison groups were defined by atopic and asthma status (neither, atopy alone, atopic asthma, nonatopic asthma, with atopy defined as any positive specific IgE (≥0.35 KU/L) to any of the 10 allergens or mixes and asthma defined as self-report of doctor-diagnosed current asthma). Multivariable regression analyses (linear, logistic, and zero inflated negative binomial where appropriate) adjusted for age, sex, race, lung function, smoking status, pack-years smoked, and use of inhaled corticosteroids were used to determine characteristics of groups and relationship with outcomes (exacerbations, clinical outcomes, CT metrics) separately in COPDGene and SPIROMICS, and then adjusted results were combined using meta-analysis. RESULTS: The prevalence of atopy was 35% and 36% in COPD subjects from SPIROMICS and COPDGene, respectively, and less than 50% overlap was seen between atopic status with asthma in both cohorts. In meta-analysis, individuals with nonatopic asthma had the most impaired symptom scores (effect size for St. George's Respiratory Questionnaire total score, 4.2; 95% CI, 0.4-7.9; effect size for COPD Assessment Test score, 2.8; 95% CI, 0.089-5.4), highest risk for exacerbations (incidence rate ratio, 1.41; 95% CI, 1.05-1.88) compared with the group without atopy or asthma. Those with atopy and atopic asthma were not at increased risk for adverse outcomes. INTERPRETATION: Asthma and atopy had incomplete overlap among former and current smokers with COPD in COPDGene and SPIROMICS. Nonatopic asthma was associated with adverse outcomes and exacerbation risk in COPD, whereas groups having atopy alone and atopic asthma had less risk.

Efficacy of Oscillation and Lung Expansion in Reducing Postoperative Pulmonary Complication.

BACKGROUND: Postoperative pulmonary complications (PPCs) cause high morbidity and mortality. Targeted treatment for patients at risk for PPCs can improve outcomes. This multicenter prospective trial examined the impact of oscillation and lung expansion (OLE) therapy, using continuous high-frequency oscillation and continuous positive expiratory pressure on PPCs in high-risk patients. METHODS: In stage I, CPT and ICD codes were queried for patients (n = 210) undergoing thoracic, upper abdominal, or aortic open procedures at 3 institutions from December 2014 to April 2016. Patients were selected randomly. Age, comorbidities, American Society of Anesthesiologists physical status classification scores, and PPC rates were determined. In stage II, 209 subjects were enrolled prospectively from October 2016 to July 2017 using the same criteria. Stage II subjects received OLE treatment and standard respiratory care. The PPCs rate (prolonged ventilation, high-level respiratory support, pneumonia, ICU readmission) were compared. We also compared ICU length of stay (LOS), hospital LOS, and mortality using t-tests and analysis of covariance. Data are mean ± SD. RESULTS: There were 419 subjects. Stage II patients were older (61.1 ± 13.7 years vs 57.4 ± 15.5 years; p < 0.05) and had higher American Society of Anesthesiologists scores. Treatment with OLE decreased PPCs from 22.9% (stage I) to 15.8% (stage II) (p < 0.01 adjusted for age, American Society of Anesthesiologists score, and operation time). Similarly, OLE treatment reduced ventilator time (23.7 ± 107.5 hours to 8.5 ± 27.5 hours; p < 0.05) and hospital LOS (8.4 ± 7.9 days to 6.8 ± 5.0 days; p < 0.05). No differences in ICU LOS, pneumonia, or mortality were observed. CONCLUSIONS: Aggressive treatment with OLE reduces PPCs and resource use in high-risk surgical patients.

Vitamin D Status Modifies the Response to Indoor Particulate Matter in Obese Urban Children with Asthma.

BACKGROUND: Indoor fine particulate air pollution (PM2.5) is linked to asthma morbidity; however, whether vitamin D status influences individual susceptibility to airborne exposures is unclear. OBJECTIVE: We aimed to determine if vitamin D modifies the effects of indoor PM2.5 on asthma symptoms in urban children. METHODS: A total of 120 children aged 5 to 12 years with physician-diagnosed asthma were evaluated at baseline and every 3 months for 9 months. Indoor PM2.5, serum 25-hydroxy vitamin D (25-OH D) levels, and asthma symptoms were simultaneously assessed at each time point. Adjusting for confounders, generalized estimating equations assessed the 3-way interaction effects of 25-OH D, obesity, and PM on asthma symptoms. RESULTS: Children were of mean (standard deviation [SD]) age 9.7 (2.2) years, 36% were obese, and 95% self-reported black race. Mean (SD) PM2.5 indoor exposure was 38.2 (42.9) µg/m3 and 25-OH D was 19.1 (7.5) ng/mL. Three-way interaction models demonstrated significantly greater PM2.5-associated effects on daytime asthma symptoms only among obese children with low 25-OH D levels (odds ratio [OR]PM2.5 = 1.26, P = .049 at vitamin D = 15.5 ng/mL, increasingly stronger PM effects at levels <15.5 ng/mL). In homes with increased PM2.5, higher 25-OH D was associated with decreased symptom odds (eg, ORVitamin D = 0.87; P = .049 at PM2.5 = 52.5 µg/m3, increasingly protective effects >52.5 µg/m3) among obese children. CONCLUSIONS: Among obese urban children with asthma, low individual 25-OH D enhanced adverse respiratory effects associated with indoor PM2.5. In high PM2.5 environments, 25-OH D was protective against asthma symptoms. Optimizing vitamin D status in children may help reduce asthma morbidity driven by indoor air pollution.

In-Home Secondhand Smoke Exposure Among Urban Children With Asthma: Contrasting Households With and Without Residential Smokers.

CONTEXT: Secondhand smoke exposure (SHSe) affects up to half of all children in the United States. Many studies have identified factors associated with in-home SHSe, but few have contrasted these factors between households with and without residential smokers. In the latter case, exposure occurs from only external sources that enter the home, such as visitors or environmental incursion. OBJECTIVE: Among children with SHSe at home, to examine demographic and psychosocial differences between households with and without residential smokers. DESIGN: Baseline analysis of an observational cohort. SETTING: Baltimore City, Maryland. PARTICIPANTS: A total of 157 children with asthma, aged 5 to 12 years. MEASURES: At-home airborne nicotine, caregiver-reported depression, asthma-related quality of life, functional social support, and demographics. Univariable comparisons were performed between SHS-exposed households with and without residential smokers. Multivariable logistic regression models were fit to examine associations between measured factors and absence of residential smokers. RESULTS: Children (78.3%) had at-home SHSe. Of these, 40.7% lived in households without residential smokers. Compared with households with residential smokers, these caregivers endorsed stronger beliefs in SHS harms and also worse functional social support and asthma-related stress, despite no differences in asthma morbidity. In adjusted models, SHS-exposed children with caregivers in the lowest tertile of functional social support (adjusted odds ratio, 3.50; 95% confidence interval, 1.12-10.99), asthma-related quality of life (2.90; 1.06-7.95), and those living alone (5.28; 1.26-22.15) had at least twice higher odds of having exclusively external SHSe than the highest tertile (P trends < .05). CONCLUSIONS: In-home SHS exposure remains alarmingly high in urban environments. However, a substantial proportion of this exposure appears to be occurring only from external sources that enter the home. Caregivers in these homes had higher desire but lower agency to avoid SHSe, driven by lack of functional support and physical isolation. Public policies targeting these factors may help remediate exposure in this especially vulnerable population.

Role of sublingual immunotherapy in the treatment of asthma: An updated systematic review.

BACKGROUND: The purpose of the systematic review is to evaluate the efficacy and safety of sublingual immunotherapy (SLIT) for the treatment of allergic asthma. METHODS: PubMed, Embase, and CENTRAL databases were searched, updating an earlier review (January 1, 2005 through May 8, 2017). Randomized, controlled studies (RCTs) were included, which reported one of the prespecified outcomes: asthma symptoms measured by control composite scores; quality of life; medication use; pulmonary physiology; and health-care utilization. For safety outcomes, RCTs and observational studies were included. Two independent reviewers extracted data, assessed risk of bias, and graded strength of evidence (SOE) for each outcome. RESULTS: Fourteen RCTs (n = 2585) assessed the efficacy of SLIT for asthma. The RCTs utilized house dust mite (HDM), birch, or grass allergen. SLIT improved asthma symptoms (high SOE), decreased use of long-term control medication, and improved forced expiratory volume in 1 second (FEV1 ) (moderate SOE). SLIT may decrease quick-relief medication use, and improve disease-specific quality of life (low SOE). For safety, 20 RCTs and 10 observational studies (n = 3621) were identified. Local (risk differences ranged from -0.03 to +0.765) and systemic allergic reactions (risk differences ranged from -0.03 to +0.06) were a common occurrence in SLIT and control groups. Life-threatening reactions were uncommon, with 3 cases of anaphylaxis and no deaths reported. CONCLUSION: There is moderate-to-high strength evidence that SLIT improves allergic asthma symptoms, reduces long-term control medication use, and improves FEV1 based on studies of HDM, birch, and grass. SLIT rarely is associated with life-threatening adverse events.

Allergen-Specific Immunotherapy in the Treatment of Pediatric Asthma: A Systematic Review.

CONTEXT: Treatment options for allergic asthma include allergen avoidance, pharmacotherapy, and allergen immunotherapy. OBJECTIVES: Summarize and update current evidence for the efficacy and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) in pediatric allergic asthma. DATA SOURCES: PubMed, Embase, Cochrane Central Register of Controlled Trials (January 1, 2005, through May 8, 2017), ClinicalTrials.gov, and the US Food and Drug Administration Adverse Event Reporting System. We reevaluated trials from our 2013 systematic review. STUDY SELECTION: We included studies with children ≤18 years of age in which researchers reported on prespecified outcomes and had an intervention arm receiving aeroallergen SCIT or SLIT. Only randomized controlled trials (RCTs) were included for efficacy. RCTs and non-RCTs were included for safety outcomes. DATA EXTRACTION: Two reviewers extracted data. We included 40 studies (17 SCIT trials, 11 SLIT trials, 8 non-RCTs for SCIT safety, and 4 non-RCTs for SLIT safety). RESULTS: We found moderate-strength evidence that SCIT reduces long-term asthma medication use. We found low-strength evidence that SCIT improves asthma-related quality of life and forced expiratory volume in 1 second. There was also low-strength evidence that SLIT improves medication use and forced expiratory volume in 1 second. There was insufficient evidence on asthma symptoms and health care use. LIMITATIONS: There were no trials in which researchers evaluated asthma symptoms using a validated tool. Study characteristics and outcomes were reported heterogeneously. CONCLUSIONS: In children with allergic asthma, SCIT may reduce long-term asthma medication use. Local and systemic allergic reactions are common, but anaphylaxis is reported rarely.

Diet Pattern and Respiratory Morbidity in the Atherosclerosis Risk in Communities Study.

RATIONALE: Dietary intake is a potential risk factor for respiratory morbidity in adult populations. Few studies capture the effect of dietary patterns, representative of the combination of nutrients consumed, on self-reported respiratory morbidity in combination with objective measures of lung function. OBJECTIVES: To evaluate patterns of dietary intake in relation to respiratory morbidity and objective measures of lung function in a U.S. METHODS: The ARIC (Atherosclerosis Risk in Communities) study investigators enrolled 15,792 participants from four U.S. communities between 1987 and 1989 and collected data using a validated food frequency questionnaire to assess diet. Principal component analysis was applied, and patterns representative of "Western" and "Prudent" diets emerged. We investigated cross-sectional associations between dietary patterns and pulmonary assessments that included asthma and chronic obstructive pulmonary disease (COPD) diagnosis, respiratory symptoms, and lung function. Multivariable Poisson regression models included quintiles of dietary patterns and potential confounders. Interaction of dietary patterns with obesity, sex, and smoking status was assessed in relation to all outcomes. RESULTS: Higher scores in the "Western" dietary pattern (quintile 5 vs. quintile 1) were associated with higher prevalence of COPD (prevalence ratio [PR], 1.62; 95% confidence ratio [CI], 1.33-1.97), wheeze (PR, 1.37; 95% CI, 1.11-1.69), cough (PR, 1.32; 95% CI, 1.32-1.59), and phlegm (PR, 1.27; 95% CI, 1.05-1.54) and lower percent predicted forced expiratory volume in 1 second (FEV1), percent predicted forced vital capacity (FVC), and FEV1/FVC ratio. Higher scores in the "Prudent" dietary pattern (quintile 5 vs. quintile 1) were associated with lower prevalence of COPD (PR, 0.82; 95% CI, 0.70-0.95) and cough (PR, 0.77; 95% CI, 0.67-0.89) and higher percent predicted FEV1 and FEV1/FVC ratio. The prevalence of asthma was not related to dietary intake. CONCLUSIONS: A "Western" dietary pattern was associated with respiratory symptoms, lower lung function, and COPD in ARIC participants.

Clinician Agreement, Self-Efficacy, and Adherence with the Guidelines for the Diagnosis and Management of Asthma.

BACKGROUND: The 2007 Guidelines for the Diagnosis and Management of Asthma provide evidence-based recommendations to improve asthma care. Limited national-level data are available about clinician agreement and adherence to these guidelines. OBJECTIVE: To assess clinician-reported adherence with specific guideline recommendations, as well as agreement with and self-efficacy to implement guidelines. METHODS: We analyzed 2012 National Asthma Survey of Physicians data for 1412 primary care clinicians and 233 asthma specialists about 4 cornerstone guideline domains: asthma control, patient education, environmental control, and pharmacologic treatment. Agreement and self-efficacy were measured using Likert scales; 2 overall indices of agreement and self-efficacy were compiled. Adherence was compared between primary care clinicians and asthma specialists. Logistic regression models assessed the association of agreement and self-efficacy indices with adherence. RESULTS: Asthma specialists expressed stronger agreement, higher self-efficacy, and greater adherence with guideline recommendations than did primary care clinicians. Adherence was low among both groups for specific core recommendations, including written asthma action plan (30.6% and 16.4%, respectively; P < .001); home peak flow monitoring, (12.8% and 11.2%; P = .34); spirometry testing (44.7% and 10.8%; P < .001); and repeated assessment of inhaler technique (39.7% and 16.8%; P < .001). Among primary care clinicians, greater self-efficacy was associated with greater adherence. For specialists, self-efficacy was associated only with increased odds of spirometry testing. Guideline agreement was generally not associated with adherence. CONCLUSIONS: Agreement with and adherence to asthma guidelines was higher for specialists than for primary care clinicians, but was low in both groups for several key recommendations. Self-efficacy was a good predictor of guideline adherence among primary care clinicians but not among specialists.

A randomised clinical trial of feedback on inhaler adherence and technique in patients with severe uncontrolled asthma.

In severe asthma, poor control could reflect issues of medication adherence or inhaler technique, or that the condition is refractory. This study aimed to determine if an intervention with (bio)feedback on the features of inhaler use would identify refractory asthma and enhance inhaler technique and adherence.Patients with severe uncontrolled asthma were subjected to a stratified-by-site random block design. The intensive education group received repeated training in inhaler use, adherence and disease management. The intervention group received the same intervention, enhanced by (bio)feedback-guided training. The primary outcome was rate of actual inhaler adherence. Secondary outcomes included a pre-defined assessment of clinical outcome. Outcome assessors were blinded to group allocation. Data were analysed on an intention-to-treat and per-protocol basis.The mean rate of adherence during the third month in the (bio)feedback group (n=111) was higher than that in the enhanced education group (intention-to-treat, n=107; 73% versus 63%; 95% CI 2.8%-17.6%; p=0.02). By the end of the study, asthma was either stable or improved in 54 patients (38%); uncontrolled, but poorly adherent in 52 (35%); and uncontrolled, but adherent in 40 (27%).Repeated feedback significantly improved inhaler adherence. After a programme of adherence and inhaler technique assessment, only 40 patients (27%) were refractory and adherent, and might therefore need add-on therapy.

The feasibility of an air purifier and secondhand smoke education intervention in homes of inner city pregnant women and infants living with a smoker.

OBJECTIVES: Secondhand smoke (SHS) and other air pollutants adversely affect the health of pregnant women and infants. A feasibility study aimed at reducing air pollution in homes of pregnant women or infants living with a smoker was completed. METHODS: In collaboration with the Baltimore City Health Department, women ≥ 18 years of age and either pregnant nonsmokers, or post-partum (any smoking status) with an infant age 0-12 months were recruited. Homes had at least one smoker. Intervention included two air purifiers and secondhand smoke education. Outcomes included feasibility, change in fine particulate matter (PM2.5), air nicotine, and salivary cotinine pre- and post-intervention. RESULTS: Fifty women were enrolled (mean age 27 years, 92% African American, 71% single, 94% Medicaid eligible, 34% reported smoking) and 86% completed the study. Of the 50 women, 32 had infants and 18 were pregnant at time of enrollment. Post- intervention, 70% of participants reported smokers were less likely to smoke indoors, and 77% had at least one air purifier turned on at the final visit. Participant satisfaction was high (91%) and 98% would recommend air purifiers. Indoor PM2.5 was significantly decreased (P < 0.001). Salivary cotinine was significantly decreased for non-smoking women (P < 0.01) but not infants, and no significant change in air nicotine occurred (P = 0.6). CONCLUSIONS: Air purifiers with SHS education is a feasible intervention in homes of women and infants. These data demonstrate reduction in indoor PM2.5 and salivary cotinine in non-smoking adults. Air purifiers are not an alternative for smoking cessation and a home/ car smoking ban. Smoking cessation should be strongly encouraged for all pregnant women, and nonsmoking mothers with infants should be counseled to completely avoid SHS exposure. This study provides support for a future intervention evaluating clinical endpoints.

Impact of Physical Activity on Reporting of Childhood Asthma Symptoms.

This study aims to determine the impact of physical activity on asthma symptom reporting among children living in an inner city. Among 147 children aged 5-12 years with physician-diagnosed asthma, we assessed asthma symptoms using twice-daily diaries and physical activity using the physical activity questionnaire for children during three 8-day periods (baseline, 3 and 6 months). Linear, logistic, and quasi-poisson regression models were used to determine the association between physical activity and asthma symptoms; adjusting for age, sex, race, BMI, caregiver's education, asthma severity, medication use, and season. A 1-unit increase in PAQ score was significantly associated with reporting more nocturnal symptoms [risk ratio (RR): 1.03; 95% CI 1.00-1.06], daytime symptoms (RR: 1.04; 95% CI 1.00-1.09), being bothered by asthma (RR: 1.05; 95% CI 1.00-1.09), and trouble breathing (RR: 1.05; 95% CI 1.00-1.10). Level of physical activity should be taken into account in clinical management of asthma and epidemiological studies of asthma symptom burden.

24-h Nitrogen dioxide concentration is associated with cooking behaviors and an increase in rescue medication use in children with asthma.

Exposure to nitrogen dioxide (NO2), a byproduct of combustion, is associated with poor asthma control in children. We sought to determine whether gas-fueled kitchen appliance use is associated with 24-h indoor NO2 concentrations and whether these concentrations are associated with asthma morbidity in children. Children aged 5-12 years old with asthma were eligible. Mean 24-h NO2 concentration was measured in the kitchen over a four-day sampling period and gas stove use was captured in time activity diaries. The relationship between stove and oven use and daily NO2 concentration was analyzed. Longitudinal analysis assessed the effect of daily NO2 exposure on symptoms, inhaler use, and lung function. Multivariate models were adjusted for age, sex, season, and maternal education. Thirty children contributed 126 participant days of sampling. Mean indoor 24-h NO2 concentration was 58(48)ppb with a median (range) of 45(12-276)ppb. All homes had gas stoves and furnaces. Each hour of kitchen appliance use was associated with an 18ppb increase in 24-h NO2 concentration. In longitudinal multivariate analysis, each ten-fold increase in previous-day NO2 was associated with increased nighttime inhaler use (OR = 4.9, p = 0.04). There were no associations between NO2 and lung function or asthma symptoms. Higher previous-day 24-h concentration of NO2 is associated with increased nighttime inhaler use in children with asthma.

A pilot feeding study for adults with asthma: The healthy eating better breathing trial.

RATIONALE: Evidence from observational studies and to a lesser extent clinical trials suggest that a healthy diet may improve symptoms and lung function in patients with asthma. We conducted a pilot study to determine the feasibility of conducting a larger scale dietary trial and to provide preliminary evidence on the impact of a healthy diet on asthma outcomes. METHODS: In a randomized, two period cross-over trial, participants with asthma received a 4-week dietary intervention followed by a usual diet (or vice versa), separated by a 4-week washout. The dietary intervention was a healthy diet rich in unsaturated fat. During the dietary intervention, participants ate three meals per week on site at the Johns Hopkins ProHealth Research Center. All remaining meals and snacks were provided for participants to consume off-site. During the control diet, participants were instructed to continue their usual dietary intake. Relevant biomarkers and asthma clinical outcomes were assessed at 0, 2, and 4 weeks after starting each arm of the study. RESULTS: Eleven participants were randomized, and seven completed the full study protocol. Among these seven participants, average age was 42 years, six were female, and six were African American. Participant self-report of dietary intake revealed significant increases in fruit, vegetable, and omega-3 fatty acid intake with the dietary intervention compared to usual diet. Serum carotenoids (eg. lutein and beta-cryptoxanthin) increased in the intervention versus control. Total cholesterol decreased in the intervention versus control diet. There was no consistent effect on asthma outcomes. CONCLUSIONS: The findings suggest that a feeding trial in participants with asthma is feasible. Larger trials are needed to definitively assess the potential benefits of dietary interventions on pulmonary symptoms and function in patients with asthma.