The associations between smoking, physical inactivity, obesity, and asthma severity in the general US population

Basis of preventive and non-pharmacological interventions in asthma

Asthma is one of the most common atopic disorders in all stages of life. Its etiology is likely due to a complex interaction between genetic, environmental, and lifestyle factors. Due to this, different non-pharmacological interventions can be implemented to reduce or alleviate the symptoms caused by this disease. Thus, the present narrative review aimed to analyze the preventive and non-pharmacological interventions such as physical exercise, physiotherapy, nutritional, ergonutritional, and psychological strategies in asthma treatment. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Asthma is an immune-mediated inflammatory condition characterized by increased responsiveness to bronchoconstrictor stimuli. Different factors have been shown to play an important role in the pathogenesis of asthma, however, the treatments used to reduce its incidence are more controversial. Physical activity is focused on the benefits that aerobic training can provide, while physiotherapy interventions recommend breathing exercises to improve the quality of life of patients. Nutritional interventions are targeted on implement diets that prioritize the consumption of fruits and vegetables and supplementation with antioxidants. Psychological interventions have been proposed as an essential non-pharmacological tool to reduce the emotional problems associated with asthma.

The longitudinal association between asthma severity and physical fitness among new York City public school youth

Severe persistent childhood asthma is associated with low physical activity and may be associated with poor physical fitness. Research on the asthma severity-fitness association longitudinally and across sociodemographic subgroups is needed to inform fitness interventions targeting youth with asthma. We evaluated the relationship between asthma severity (categorized as severe, mild, or no asthma) and subsequent fitness in New York City (NYC) public school youth enrolled in grades 4-12 using the NYC Fitnessgram dataset (2010-2018). Longitudinal mixed models with random intercepts were fit to test the association between asthma severity and one-year lagged fitness z-scores by clustering repeated annual observations at the student level. Models were adjusted for sex, race/ethnicity, grade level, poverty status, time, and stratified by sociodemographic factors. The analytic sample included 663,137 students (51% male; 31% non-Hispanic Black, 40% Hispanic; 55% in grades 4-8, 70% high poverty; 87%, 11% and 1% with no, mild, and severe asthma, respectively). Students with severe asthma and mild asthma demonstrated -0.19 (95% CI, -0.20 to -0.17) and - 0.10 (95% CI, -0.11 to -0.10), respectively, lower fitness z-scores in the subsequent year relative to students without asthma. After stratifying by demographics, the magnitude of the asthma severity-fitness relationship was highest for non-Hispanic white vs. all other racial/ethnic subgroups, and was similar across sex, grade level, and household poverty status. Overall, we observed an inverse longitudinal relationship between asthma severity and subsequent fitness among urban youth, particularly non-Hispanic Whites. Future research should examine how neighborhood-level factors impact the asthma severity-fitness relationship across racial/ethnic subgroups.

Housing environments and asthma outcomes within population-based samples of adults and children in NYC

Exposure to indoor environmental risk factors is associated with patterns of asthma morbidity. In this study, we assessed the relationship between housing type (i.e., home ownership, public housing, rental assistance, rent-controlled housing and other rental housing) and asthma outcomes among New York City (NYC) adults and children (ages 1-13). We used the 2019 NYC Community Health Survey (CHS) and 2019 NYC KIDS survey to analyze associations between housing type and ever having been diagnosed with asthma ("ever asthma") and experiencing a past-year asthma attack. We further examined whether associations were modified by smoking status (among adults), smoking within the home (among children), and overweight/obesity. Among adults, living in public housing, compared to home ownership, was associated with higher odds of ever asthma (odds ratio [OR] = 1.95; 95% confidence interval [CI] = 1.35, 2.84), and past-year asthma attack (OR = 2.24; 95% CI 1.21,4.18). Living in rental assistance housing was also significantly associated with ever asthma (OR = 1.75; 95% CI 1.16, 2.66). Associations between public or rental assistance housing and ever asthma were marginally non-significant among children. Associations between living in public or rental assistance housing and ever asthma were more pronounced among ever smokers than among never smokers. Housing environments remain important predictors of both pediatric and adult asthma morbidity. Associations between living in subsidized housing and asthma outcomes among adults are most apparent among ever smokers.

The challenge of addressing obesity in people with poorly controlled asthma

Objective

There is a high prevalence of obesity in people with asthma, and obesity is associated with poorly controlled asthma. Significant weight loss might improve asthma control: the purpose of this study was to investigate patient characteristics and factors that might affect implementation of a weight loss and/or roflumilast intervention, to target both obesity and asthma.

Methods

A cross-sectional study of people with obesity and poorly controlled asthma performed at 13 sites across the United States.

Results

One hundred and two people participated in this study. Median BMI was 37 (IQR 35-42). The majority, 55%, were African American and 76% were female. Fifty two percent had very poorly controlled asthma. Most participants were quite sedentary (70% reported being inactive or participating only in light-intensity activities according to the Stanford Brief Activity Survey). Participants reported significant impairments related to physical function on the Impact of Weight on Quality of Life-Lite questionnaire (median score 67 [IQR 41-84]). Thirty-five percent of participants reported mild, and 2 % moderate, depressive symptoms as assessed by the Patient Health Questionnaire-9.

Conclusions

Poorly controlled asthma and obesity often affect minority populations and are associated with significant impairments in health related to physical function and low levels of physical activity that might complicate efforts to lose weight. Interventions targeted at poorly controlled asthma associated with obesity in the United States need to address factors complicating health in underserved communities, such as increasing opportunities for physical activity, while also managing activity limitations related to the combination of asthma and obesity.

An international Delphi consensus study to define motivational communication in the context of developing a training program for physicians

Poor health behaviors (e.g., smoking, poor diet, and physical inactivity) are major risk factors for noncommunicable chronic diseases (NCDs). Evidence supporting traditional advice-giving approaches to promote behavior change is weak or short lived. Training physicians to improve their behavior change counseling/communication skills is important, yet the evidence for the efficacy and acceptability of existing training programs is lacking and there is little consensus on the core competencies that physicians should master in the context of NCD management. The purpose of this study is to generate an acceptable, evidence-based, stakeholder-informed list of the core communication competencies that physicians should master in the context of NCD management. Using a modified Delphi process for consensus achievement, international behavior change experts, physicians, and allied health care professionals completed four phases of research, including eight rounds of online surveys and in-person meetings over 2 years (n = 13-17 participated in Phases I, III, and IV and n = 39-46 in Phase II). Eleven core communication competencies were identified: reflective listening, expressing empathy, demonstrating acceptance, tolerance, and respect, responding to resistance, (not) negatively judging or blaming, (not) expressing hostility or impatience, eliciting "change-talk"/evocation, (not) being argumentative or confrontational, setting goals, being collaborative, and providing information neutrally. These competencies were used to define a unified approach for conducting behavior change counseling in medical settings: Motivational Communication. The results may be used to inform and standardize physician training in behavior change counseling and communication skills to reduce morbidity and mortality related to poor health behaviors in the context of NCD prevention and management.

Heterogeneity of Paucigranulocytic Asthma: A Prospective Cohort Study with Hierarchical Cluster Analysis

BACKGROUND

Asthma, a heterogeneous disease, can be divided into 4 inflammatory phenotypes using induced sputum cell counts-eosinophilic asthma (EA), neutrophilic asthma (NA), mixed granulocytic asthma, and paucigranulocytic asthma (PGA). Although research has focused on EA and NA, there is little known about PGA.

OBJECTIVE

To study the heterogeneity of PGA and identify possible PGA clusters to guide clinical treatment.

METHODS

Patients with PGA were grouped by hierarchical cluster analysis and enrolled into a prospective cohort study to validate the clusters, relative to future risk of asthma exacerbations in a real-world setting. Clusters were validated by tree analysis in a separate population. Finally, we explored PGA stability.

RESULTS

Cluster analysis of 145 patients with PGA identified 3 clusters: cluster 1 (n = 110, 75.9%) was "mild PGA," cluster 2 (n = 20, 13.8%) was "PGA with psychological dysfunction and rhinoconjunctivitis and other allergic diseases," and cluster 3 (n = 15, 10.3%) was "smoking-associated PGA." Cluster 3 had significantly increased risk of severe exacerbation (relative risk [RR] = 6.43, P = .01), emergency visit (RR = 8.61, P = .03), and hospitalization (RR = 12.94, P < .01). Results of the cluster analysis were successfully validated in an independent PGA population classified using decision tree analysis. Although PGA can transform into or develop from other phenotypes, 70% were stable over time.

CONCLUSIONS

Among 3 identified PGA clusters, cluster 3 had a higher risk of severe exacerbation. PGA heterogeneity indicates the requirement of novel targeted interventions.

Are adults with asthma less physically active? A systematic review and meta-analysis

OBJECTIVE

To systematically review the evidence on whether having current, ever asthma and asthma control is associated with levels of total, moderate and vigorous physical activity.

METHODS

We searched EMBASE, MEDLINE, and CINAHL databases, limiting searches to English language papers from inception until Oct 2019. We synthesized the evidence comparing levels of total, moderate and vigorous physical activity between adults with and without current asthma or ever asthma by random effects meta-analyses.

RESULTS

A total of 25 studies were included, with 18 of these included in meta-analyses. A meta-analysis of 4 case-control studies found that adults with current asthma were less active, with 942.12 steps fewer per day, than adults without current asthma (SMD = -0.39, 95%CI: -0.54, -0.24, I² = 0). Meta-analysis of four-high quality cross-sectional studies found that those with current or ever asthma were more likely to be inactive than those without asthma (binary OR _{current asthma} = 0.85, 95%CI: 0.82, 0.89, I² = 45.6%, and binary OR _{ever asthma} = 0.83, 0.75, 0.91, I² = 0, respectively). Meta-analysis, inclusive of all 10 cross-sectional studies with binary ORs, supported this finding. There was also some evidence that adults with current asthma and ever asthma (6 studies with categorical ORs) were less likely to exercise moderately and vigorously, but these meta-analyses were limited by high heterogeneity. No synthesis of the studies considering asthma control was possible.

CONCLUSION

Adults with current or ever asthma had lower levels of total, moderate and vigorous physical activity than those without asthma and may be missing out on the health benefits of being physically active. The association between asthma control and physical activity warrants further investigation.

The risk of osteoporosis in patients with asthma

It is well-known that use of continuous systemic corticosteroids (SG) affects bone metabolism, bone mineral density (BMD), and ultimately increases the risk of osteoporosis. In patients with asthma, on the other hand, the effects of long-term high-dose inhaled corticosteroids (ICS) on BMD and risk of osteoporotic fractures is controversial. The reasons for this inconsistency could be explained by the fact that only few long-term studies investigating the effect of ICS in patients with asthma exist. The studies are characterized by different study designs and duration of ICS exposure, small study populations, and differences between the used ICS. The aim of this article is to unravel which factors, if any, that contribute to an increased risk of osteoporosis in patients with asthma and to summarize the evidence regarding adverse effects of ICS on bone metabolism, BMD and osteoporotic fractures in patients with asthma.

Barriers to daily life physical activities for Brazilian children with asthma: a cross-sectional study

BackgroundObjective: To identify barriers to daily life physical activities (DLPA) and to evaluate physical activity levels for children with asthma and without asthma.Method: This is a cross-sectional study that enrolled 130 children with asthma and 54 non-asthma, from 7 to 12 years old. All of the children in both groups used an accelerometer for 6 consecutive days to assess DLPA and completed a questionnaire to evaluate barriers to physical activity. Accelerometer was used to measure each child's total number of steps, as well as the number of steps and the time spent in moderate-to-vigorous physical activity (MVPA). The barrier questionnaire to DLPA included 11 questions, divided into three domains: personal, social and environmental.Results: The most commonly described barrier to DLPA in the asthma and non-asthma groups was an unsafe environment (23.6% vs 28.5%, respectively). The asthma group reported having asthma (19%) and lack of parental encouragement (17.3%) as being other important barriers to DLPA. It was also observed that the asthma and non-asthma groups presented similar values for the total number of steps (13,379 ± 3,837 vs 14,055 ± 3,914, respectively, p > 0.05), number of steps in MVPA (5,654 ± 1,988 vs. 6,025 ± 2,058, p > 0.05), and time spent in MVPA (46 ± 16 min vs. 50.8 ± 14.7 min, p > 0.05).Conclusions: An unsafe environment is the main barrier to physical activity for Brazilian children. Moreover, a lack of parental encouragement and having asthma were considered to be barriers to physical activity. And lastly, children have similar levels of physical activity whether they have asthma or do not have asthma.

Prevalence and determinants of asthma among aboriginal adolescents in Canada

Objective: The objective of the study was to determine the prevalence and associated risk factors of asthma in Aboriginal adolescents in Canada based on the Canadian Aboriginal Peoples Survey (APS) 2012. Few studies have investigated the prevalence and risk factors of asthma in Aboriginal adolescents in Canada. Methods: Data from the cross-sectional APS 2012 were analyzed to accomplish the objective. Logistic regression analysis was utilized to determine significant risk factors of lifetime diagnosis of asthma among Aboriginal adolescents. The outcome of interest for adolescents was based on the question: "Do you have asthma that have been diagnosed by a health professional?" Individual, environmental, and contextual factors were tested for an association with lifetime diagnosis of asthma among adolescents. Results: The overall prevalence of lifetime diagnosis of asthma was 16.0%. The prevalence of lifetime diagnosis of asthma was 16.8% for adolescent boys and 15.3% for adolescent girls. Based on multivariable logistic regression analysis, the risk factors of lifetime diagnosis of asthma were: age, income, being overweight, smoking inside the home, having one to two children under 18 years in the household, history of bronchitis, living in an urban residence, education, and geographical location. Female sex was reported to have a protective effect on or reduce risk of the prevalence of lifetime diagnosis of asthma compared to the male sex. Conclusions: Lifetime diagnosis of asthma prevalence appears to be lower in Aboriginal adolescent girls than in adolescent boys. Lifetime diagnosis of asthma prevalence in these adolescents is associated with age, income, education, being overweight, smoking inside the home, history of bronchitis, and location of residence, both geographical region and urban residence. The prevalence of lifetime diagnosis of asthma among Aboriginal adolescent is higher compared to the general adolescent population in Canada.

Physical activity among Canadian adults with obstructive respiratory diseases

The objective of this study was to investigate the amount and modes of physical activity in which adults with obstructive respiratory disease engage. Data from respondents with self-reported asthma (n = 4293), chronic obstructive pulmonary disease (COPD) (n = 3118), both diseases (n = 1569), and neither obstructive respiratory disease (n = 64 175); these data are from the Canadian Community Health Survey (2011-2012). Logistic regressions were used to assess associations between modes of physical activity and type of respiratory disease. Linear regressions were used to investigate the association between daily energy expenditure and respiratory disease. Adults with COPD and both diseases had the lowest participation in all modes of physical activity. Those with both diseases were less likely to report walking (odds ratio (OR) = 0.74, 95% confidence interval (CI) = 0.63-0.88), while those with COPD were less likely to report participation in endurance activities (OR = 0.79, 95% CI = 0.68-0.92), compared with those with neither obstructive respiratory disease. Those with asthma had similar daily energy expenditure levels and physical activity preferences compared with those with neither obstructive respiratory disease. In conclusion, adults with COPD and both asthma and COPD were less likely to engage in common activities such as walking, while physical activity levels among adults with asthma did not differ from the general population.

Asthma-related health services and asthma control among women in Puerto Rico

Objectives:

This study evaluates social, behavioral, and environmental determinants to differentiate between active and inactive asthma and how predisposing, enabling, and need factors elucidate asthma-related health services and asthma control among women in Puerto Rico.

Methods:

This study analyzed secondary cross-sectional data from a subsample of 625 adult females who participated in the Asthma Call Back Survey in Puerto Rico. Logistic and multinomial regression analyses were conducted to examine associations between explanatory variables and asthma outcomes.

Results:

In total, 63% of women reported active asthma, from which 37.9% have not well controlled or very poorly controlled asthma. Women with active asthma were significantly more likely to be out of work, have middle income (US$25,000–<US$35,000), and be obese (≥30 kg/m²). Perceived need of health status is a good predictor to know the odds ratio of women to use emergency room. Women with poorly controlled asthma were significantly associated with increased units of physician urgent visits and emergency room visits.

Conclusion:

The findings confirmed significant determinants for active asthma and adds information on odds ratio for sensitive subgroups that utilize asthma-related health services in higher proportion than their counterparts. These associations suggest a development of asthma management plan targeting women to control the condition and reduce health-care utilization.

A Systematic Review of Associations of Physical Activity and Sedentary Time with Asthma Outcomes

BACKGROUND

Physical inactivity and high sedentary time are associated with adverse health outcomes in several diseases. However, their impact in asthma is less clear.

OBJECTIVE

We aimed to synthesize the literature characterizing physical activity and sedentary time in adults with asthma, to estimate activity levels using meta-analysis, and to evaluate associations between physical activity and sedentary time and the clinical and physiological characteristics of asthma.

METHODS

Articles written in English and addressing the measurement of physical activity or sedentary time in adults ≥18 years old with asthma were identified using 4 electronic databases. Meta-analysis was used to estimate steps/day in applicable studies.

RESULTS

There were 42 studies that met the inclusion criteria. Physical activity in asthma was lower compared with controls. The pooled mean (95% confidence interval) steps/day for people with asthma was 8390 (7361, 9419). Physical activity tended to be lower in females compared with males, and in older people with asthma compared with their younger counterparts. Higher levels of physical activity were associated with better measures of lung function, disease control, health status, and health care use. Measures of sedentary time were scarce, and indicated a similar engagement in this behavior between participants with asthma and controls. High sedentary time was associated with higher health care use, and poorer lung function, asthma control, and exercise capacity.

CONCLUSIONS

People with asthma engage in lower levels of physical activity compared with controls. Higher levels of physical activity may positively impact on asthma clinical outcomes. Sedentary time should be more widely assessed.

Asthma and smoking-induced airway disease without spirometric COPD

Due to the high prevalence rates of cigarette smoking and asthma, current and ex-smokers frequently develop chronic airway disease without spirometric evidence of chronic obstructive pulmonary disease (COPD), either alone or associated with asthma. This review considers the classification, clinical outcomes, inflammatory and imaging variables, phenotypes, and management of current and ex-smokers with airway disease without COPD, focusing on overlaps in those with and without asthma. These individuals have more respiratory symptoms, worse quality of life, increased exacerbation rates, reduced lung function and more comorbidities than never-smokers with asthma or healthy never-smokers. As well as clinical features, airway inflammatory and structural changes in smoking-induced airway disease without COPD overlap with those found in smokers with asthma. Cigarette smoking is associated with worse clinical outcomes in some phenotypes of asthma. Management involves public health measures to control exposure to tobacco smoke, personal advice on smoking cessation and the use of appropriate targeted therapies, although evidence is limited on their effectiveness. Understanding the mechanisms, natural history and management of current and ex-smokers with asthma and smoking-induced airway disease without COPD is a priority for future research.

Physical activity and incident asthma in adults: the HUNT Study, Norway

OBJECTIVE

We aimed to investigate the associations of physical activity and change in physical activity with incident asthma in a cohort of Norwegian adults.

DESIGN

We conducted a prospective cohort study using data on self-reported physical activity from 3 waves of the Nord-Trøndelag Health Study. Physical activity was reported at the first and second surveys (1985-1986 and 1995-1997). Physical activity was defined from the second survey as inactive or active and the active group was further defined as very low, low, moderate and high. Change in physical activity was defined from the first and second surveys.

SETTING

A large population-based health survey in Norway.

PARTICIPANTS

We followed 18 894 adults over 11 years who were free from asthma at baseline in 1995-1997.

OUTCOME

Incident asthma was reported in the third survey (2006-2008).

RESULTS

The cumulative incidence of asthma was 3.6% over the 11 years. The adjusted OR for incident asthma among active participants compared with inactive participants was 0.95 (95% CI 0.69 to 1.34). The adjusted OR for those who were active in the first or second survey versus those who were inactive in both surveys was 0.64 (95% CI 0.34 to 1.38); however, this association was strongly attenuated in sensitivity analysis (OR 0.93, 95% CI 0.38 to 3.09).

CONCLUSIONS

We did not observe statistically significant associations of physical activity or change in physical activity with incident asthma in adults over the 11-year follow-up.

Pulmonary effects of active smoking and secondhand smoke exposure among adolescent students in Juárez, Mexico

BACKGROUND

Youth smoking trends among Latin American countries, including Mexico, are on the rise. Notably, although the high prevalence of smoking in teens has been well documented in the literature, few studies have evaluated the impact of smoking and secondhand smoke (SHS) exposure on their respiratory system.

OBJECTIVE

To investigate the effects of smoking and SHS exposure on the respiratory health and lung function among eighth-grade students in Juárez, Mexico.

METHODS

A cross-sectional study was undertaken on a sample of convenience. The study outcomes centered on evaluating 300 students' lung function by spirometry (forced expiratory volume in 1 second [FEV1], forced expiratory volume in 1 second/forced vital capacity ratio [FEV1/FVC], and forced mid-expiratory flow rate [FEF25%-75%]) and their respiratory health (smoking behavior and SHS exposure) by their self-reported responses to a standardized respiratory questionnaire. The study outcomes were compared among three distinct groups: 1) nonsmokers/nonexposed to SHS; 2) nonsmokers/exposed to SHS; and 3) smokers.

RESULTS

The majority of the study participants were 14 years old (85%), females (54%), who attended eighth grade in a public school setting (56%). Approximately, half reported being of low socioeconomic status (49%) and nonsmokers/exposed to SHS (49%). The lung function parameters of smokers were found to be lower (FEV1 =62.88±10.25; FEV1/FVC =83.50±14.15; and FEF25%-75% =66.35±12.55) than those recorded for the nonsmokers/exposed to SHS (FEV1 =69.41±11.35; FEV1/FVC =88.75±15.75; and FEF25%-75% =78.90±14.65) and significantly reduced when compared to the nonsmokers/nonexposed to SHS (FEV1 =79.14±13.61; FEV1/FVC =94.88±21.88; and FEF25%-75% =87.36±17.02) (P<0.001). Similarly, respiratory complaints were more prevalent among smokers and those exposed to SHS when compared to nonsmokers/nonexposed to SHS.

CONCLUSION

Our findings suggest that initiation of cigarette smoking and, to a lesser extent, exposure to SHS in adolescence leads to increased respiratory symptoms and reduction of pulmonary function test values. Public health initiatives that aim to prevent smoking initiation, assist in cessation, and lessen SHS exposure of adolescents need to be school-based and employed as early as middle school.

Sociodemographic, health-related and lifestyle correlates of physical activity in adults with current asthma

OBJECTIVE

Regular physical activity is associated with better asthma control; however, little is known of the determinants of physical activity in a population of adults with asthma. Thus, the purpose of this study was to identify important sociodemographic, health and lifestyle correlates of physical activity among adults with asthma.

METHODS

Data from adults with asthma aged 18-44 years (n = 2740) from the Canadian Community Health Survey (CCHS), 2011-2012 annual component were used for analysis. The main outcome was Daily Energy Expenditure (DEE). This variable was based on frequency and duration of leisure activities in the past 3 months. Self-reported sociodemographic (age, sex, total household income, highest education level, and ethnicity), health-related (body mass index (BMI), self-perceived health, mood disorder, anxiety disorder, and asthma symptoms/attacks, past year) and lifestyle (type of smoker, sedentary time, fruit and vegetable consumption) variables were assessed as correlates for DEE. Data were analysed using linear regressions.

RESULTS

In the final model, sociodemographic correlates accounted for 4.2% of the variation in DEE. Adding health correlates increased the R² to 12.1%. Finally, adding lifestyle correlates increased the R² to 17.6%.

CONCLUSIONS

In adults with current asthma, the main correlates of physical activity are age, total household income, BMI, self-perceived health, anxiety disorder, sedentary time, and fruit and vegetable consumption. These data are important for informing education and exercise interventions for adults with asthma. Future research is needed to determine asthma-specific correlates of physical activity.

Identification of vitamin D sensitive pathways during lung development

BACKGROUND

We have previously shown that vitamin D deficiency has a detrimental impact on lung development. In this study, we aimed to identify the mechanisms linking vitamin D with lung development using a mouse model of dietary manipulation.

METHODS

Female offspring were euthanized at different time-points; embryonic day (E)14.5, E17.5 or postnatal day (P)7. Lung tissue was collected for mass spectrometry-based proteomic analysis. Label-free quantitation was used to identify the differentially expressed proteins and ELISA confirmed the expression of selected proteins. Lungs from separate groups of mice were fixed and processed for stereological assessment of lung structure.

RESULTS

No differences in protein expression between vitamin D deficient and replete mice were detected at E14.5 and E17.5, whereas 66 proteins were differentially expressed in P7 lungs. The expression of pulmonary surfactant-associated protein B (SP-B) and peroxiredoxin 5 (PRDX5) were reduced in P7 lungs of vitamin D deficient mice, while the production of collagen type Ι alpha 1 (COL1A1) was higher in lungs of vitamin D deficient mice. There were no differences in lung volume, parenchymal volume, volume of airspaces or surface area of airspaces between vitamin D deficient and vitamin D replete mice across three time-points.

CONCLUSIONS

The difference in protein expression during the early postnatal time-point suggests that vitamin D deficiency may induce alterations of lung structure and function in later life during alveolarization stage through impaired pulmonary surfactant production and anti-oxidative stress ability as well as enhanced collagen synthesis. These data provided a plausible mechanism linking maternal vitamin D deficiency with altered postnatal lung function.

Sex difference in the association between obesity and asthma in U.S. adults: Findings from a national study

BACKGROUND

Obesity and asthma are both prevalent in the U.S. The a few studies that have examined the differences in association between obesity and asthma by sex provided mixed results. Reason for the sex differences is not well understood.

OBJECTIVE

Using U.S. nationally representative data we aimed to examine the association between obesity and asthma and potential sex differences.

METHODS

Data were obtained from the 2012 National Health Interview Survey (n = 33,153 adults, 4197 had asthma). Asthma was determined by a positive response to the question "Has a doctor or health care professional ever told you had asthma?" Obesity was determined as a Body Mass Index (BMI)≥30. Obese status was categorized as BMI = 30-34.9 (Class I obesity), BMI = 35-39.9 (Class II obesity), and BMI≥40 (Class III obesity).

RESULTS

The prevalence of asthma was 12.6% (11.0% in men, 14.2% in women), and was higher in the obese than non-obese individuals (16.6% vs. 11.1%, p < 0.0001). After controlling for potential confounders, Class I obesity (OR = 1.27, 95% CI = 1.11-1.44), Class II obesity (OR = 1.55, 95% CI = 1.31-1.84), Class III obesity (OR = 1.85, 95% CI = 1.54-2.21) were positively associated with asthma. The association between Class III obesity and asthma was stronger in women than men (2.11 (1.70-2.63) vs. 1.40 (1.01-1.96), p < 0.05), although the sex difference in the association between BMI and asthma was not significant. Positive associations between class II and class III obesity and asthma were observed among young and middle-aged women compared to young and middle-aged men. Stratified by allergic status, obesity remained being positively associated with asthma.

CONCLUSION

The prevalence of asthma was higher in women than men. Obesity (and BMI) was positively associated with asthma, overall or stratified by allergic status. The association between Class III obesity and asthma was stronger in women. Obesity and sex may be taken into consideration for the management of asthmatic patients.

Cigarette smoking and emergency care utilization among asthmatic adults in the 2011 Asthma Call-back Survey

OBJECTIVE

Estimate the association between smoking and emergency care in the past 12 months among asthmatic adults in a nationally representative sample.

METHODS

Using the 2011 Asthma Call-Back Survey, the association between smoking status and emergency department (ED) and urgent visits among asthmatic adults (n = 12 339) was assessed through multivariable logistic regression by a cross-sectional study design. Analyses used survey weights for US population-based estimates. Attributable and population attributable risk were calculated to describe the potential benefits of smoking cessation.

RESULTS

Adjusting for potential confounders, during the past 12 months former smokers had 1.30 (95% CI: 0.97, 1.74) times the odds and current smokers had 1.46 (95% CI: 1.05, 2.03) times the odds of visiting the ED compared to never smokers. Former smokers had 1.28 (95% CI: 0.99, 1.65) times the odds and current smokers had 1.29 (95% CI: 0.96, 1.73) times the odds of urgent visits compared to never smokers. Among adult asthmatics, an estimated 9% of ED visits and 6% of urgent visits can be attributed to current smoking while 7% of ED visits and 7% of urgent visits can be attributed to former smoking.

CONCLUSIONS

Current and former smokers are more likely to need emergency care than never smokers. About 10% of emergency care visits among asthmatics can be attributed to smoking assuming smoking is causally related to emergency care. Long-term effective management of asthma, particularly the prevention and cessation of smoking, could reduce emergency care use and health care costs.

Vitamin D deficiency at 16 to 20 weeks' gestation is associated with impaired lung function and asthma at 6 years of age

RATIONALE

Vitamin D deficiency is associated with chronic lung disease. We have previously shown in an in vivo mouse model that maternal vitamin D deficiency is associated with alterations in early life lung structure and function. However, there are limited data to support a relationship between maternal vitamin D deficiency during the early stages of lung development and postnatal lung function in human populations.

OBJECTIVES

To assess the association between maternal vitamin D deficiency, postnatal lung function, and asthmatic status in a longitudinal birth cohort.

METHODS

Serum was collected at 16 to 20 weeks' gestation at the time of recruitment in a community-based prospective birth cohort for measurement of vitamin D (25[OH]D). Lung function was assessed by spirometry according to American Thoracic Society guidelines in children at 6 and 14 years of age. Demographic and clinical history data were collected by questionnaire at recruitment and at the follow-up visits.

MEASUREMENTS AND MAIN RESULTS

FVC Z-scores in both sexes (β, 0.007 [95% confidence interval (CI), 0.001-0.013]; P = 0.02) and FEV1 Z-scores in girls (β, 0.007 [95% CI, 0.001-0.013]; P = 0.02) were positively associated with maternal serum 25(OH)D at 6 years of age. These associations were mostly absent at 14 years of age. Maternal vitamin D deficiency was positively associated with asthma at 6 years of age but only in boys (odds ratio, 3.03 [95% CI, 1.02-9.02]; P = 0.04).

CONCLUSIONS

This study supports the notion that vitamin D deficiency during lung development may impact on postnatal lung growth and increase the risk of developing lung disease.

Vitamin D deficiency causes airway hyperresponsiveness, increases airway smooth muscle mass, and reduces TGF-β expression in the lungs of female BALB/c mice

Vitamin D deficiency is associated with disease severity in asthma. We tested whether there is a causal association between vitamin D deficiency, airway smooth muscle (ASM) mass, and the development of airway hyperresponsiveness (AHR). A physiologically relevant mouse model of vitamin D deficiency was developed by raising BALB/c mice on vitamin D‐deficient or ‐replete diets. AHR was assessed by measuring lung function responses to increasing doses of inhaled methacholine. Five‐micron sections from formalin‐fixed lungs were used for ASM measurement and assessment of lung structure using stereological methods. Transforming growth factor (TGF)‐β levels were measured in bronchoalveolar lavage fluid (BALF). Lungs were dissected from embryonic day (E) 17.5 vitamin D‐deficient and ‐replete fetal mice for quantification of ASM density and relative gene expression of TGF‐β signaling pathway molecules. Eight‐week‐old adult vitamin D‐deficient female mice had significantly increased airway resistance and ASM in the large airways compared with controls. Vitamin D‐deficient female mice had a smaller lung volume, volume of parenchyma, and alveolar septa. Both vitamin D‐deficient male and female mice had reduced TGF‐β levels in BALF. Vitamin D deficiency did not have an effect on ASM density in E17.5 mice, however, expression of TGF‐β1 and TGF‐β receptor I was downregulated in vitamin D‐deficient female fetal mice. Decreased expression of TGF‐β1 and TGF‐β receptor I during early lung development in vitamin D‐deficient mice may contribute to airway remodeling and AHR in vitamin D‐deficient adult female mice. This study provides a link between vitamin D deficiency and respiratory symptoms in chronic lung disease.

Vitamin D deficiency caused airway hyperresponsiveness and increased airway smooth muscle mass in the airways of adult female mice. Vitamin D deficiency also reduced transforming growth factor (TGF)‐β1 protein levels in both male and female mice, as well as reduced gene expression of TGF‐β1 and TGF‐β receptor I in female E17.5 fetal pups. These observations may provide a link between vitamin D deficiency and respiratory symptoms in chronic lung disease.

Managing older patients with coexistent asthma and chronic obstructive pulmonary disease: diagnostic and therapeutic challenges

Asthma and chronic obstructive pulmonary disease (COPD) are common obstructive airway diseases, especially among older people. These conditions are associated with a significant and increasing disease burden. The diagnosis and management of asthma and COPD in older populations are complex, and consequently clinicians are faced with many therapeutic and diagnostic challenges. Both aging and obstructive airway diseases are associated with complex co-morbidities and these coexisting illnesses confound management. Moreover, the age-related physiological changes that occur in the lungs may lead to airflow limitation, and this may be difficult to distinguish from an active disease state. In practice, management of asthma and COPD is informed by disease-specific clinical practice guidelines; however, most older people with these conditions are excluded from clinical trials that are designed to inform practice, creating major evidence gaps. Furthermore, seldom do clinical practice guidelines consider the complexities of management in older populations. The problems experienced by older people are complex and multifactorial and our approach to management must reflect these challenges. Opportunities exist to improve the management and outcomes for older people with obstructive airway disease and there is an urgent need for clinical trials to test management approaches in this population; current research must consider the challenges and evidence gaps that exist.

Vitamin D deficiency and the lung: disease initiator or disease modifier?

Vitamin D deficiency is a global public health problem and has been associated with an increased incidence and severity of many diseases including diseases of the respiratory system. These associations have largely been demonstrated epidemiologically and have formed the basis of the justification for a large number of clinical supplementation trials with a view to improving disease outcomes. However, the trials that have been completed to date and the ongoing experimental studies that have attempted to demonstrate a mechanistic link between vitamin D deficiency and lung disease have been disappointing. This observation raises many questions regarding whether vitamin D deficiency is truly associated with disease pathogenesis, is only important in the exacerbation of disease or is simply an indirect biomarker of other disease mechanisms? In this review, we will briefly summarize our current understanding of the role of vitamin D in these processes with a focus on lung disease.

State quitlines and cessation patterns among adults with selected chronic diseases in 15 states, 2005-2008

Introduction

The death rate of people who have a chronic disease is lower among former smokers than current smokers. State tobacco cessation quitlines are available for free in every state. The objective of our study was to compare demographic characteristics, use of quitline services, and quit rates among a sample of quitline callers.

Results

Among 195,057 callers, 32.3% reported having 1 or more of the following chronic diseases: 17.7%, asthma; 5.9%, coronary artery disease; 11.1%, chronic obstructive pulmonary disease; and 9.3%, diabetes; 9.0% had 2 or more chronic diseases. Callers who had a chronic disease were older and better educated; more likely to be female, have Medicaid or other health insurance, and have used tobacco for 20 years or more; and less likely to quit smoking (22.3%) at 7 months than callers who had none of these chronic diseases (29.7%).

Conclusion

About one-third of tobacco users who call state quitlines have a chronic disease, and those who have a chronic disease are less likely to quit using tobacco. Continued efforts are needed to ensure cessation treatments are reaching tobacco users who have a chronic disease and to develop and test ways to increase quit rates among them.

Obesity and other modifiable factors for physical inactivity measured by accelerometer in adults with knee osteoarthritis

OBJECTIVE

To investigate the public health impact of obesity and other modifiable risk factors related to physical inactivity in adults with knee osteoarthritis (OA).

METHODS

The frequency of inactivity as defined by the US Department of Health and Human Services was assessed from objective accelerometer monitoring of 1,089 participants (ages 49-84 years) with radiographic knee OA during the Osteoarthritis Initiative 48-month visit (2008-2010). The relationship between modifiable factors (weight status, dietary fat, fiber, smoking, depressive symptoms, knee function, knee pain, and knee confidence) with inactivity was assessed using odds ratios (ORs) and attributable fractions (AFs), controlling for descriptive factors (age, sex, race, education, lives alone, employment, frequent knee symptoms, and comorbidity).

RESULTS

Almost half (48.9%) of participants with knee OA were inactive. Being overweight (OR 1.8, 95% confidence interval [95% CI] 1.2-2.5) or obese (OR 3.9, 95% CI 2.6-5.7), having inadequate dietary fiber intake (OR 1.6, 95% CI 1.2-2.2), severe knee dysfunction (OR 1.9, 95% CI 1.3-2.8), and severe pain (OR 1.7, 95% CI 1.1-2.5) were significantly related to inactivity, controlling for descriptive factors. Modifiable factors with significant average AFs were being overweight or obese (AF 23.8%, 95% CI 10.5-38.6%) and inadequate dietary fiber (AF 12.1%, 95% CI 0.1-24.5%), controlling for all factors.

CONCLUSION

Being obese or overweight, the quality of the diet, severe pain, and severe dysfunction are significantly associated with physical inactivity in adults with knee OA. All components should be considered in designing physical activity interventions that target arthritis populations with low activity levels.

Clinical outcomes and inflammatory biomarkers in current smokers and exsmokers with severe asthma

BACKGROUND

Clinical outcomes are worse in current smokers and exsmokers with mild-to-moderate asthma compared with never smokers, but little is known about the influence of smoking status in patients with severe asthma.

OBJECTIVES

We sought to examine the association of current or previous cigarette smoking with clinical and inflammatory variables in patients with severe asthma.

METHODS

We compared patients' demographics, disease characteristics, and biomarkers of inflammation in current smokers (n=69 [9%]), exsmokers (n=210 [28%]), and never smokers (n=461 [62%]) with severe asthma (n=760) recruited to the British Thoracic Society Severe Asthma Registry.

RESULTS

Current smokers had poorer asthma control, more unscheduled health care visits, more rescue courses of oral steroids, and higher anxiety and depression scale scores than exsmokers or never smokers. Current smokers had a reduced proportion of sputum eosinophils compared with never smokers (1% and 4%, respectively) and lower fraction of expired nitric oxide (50 mL/s; 14 ppb and 35 ppb, respectively). Exsmokers compared with never smokers had an increased proportion of sputum neutrophils (59% and 43%, respectively) but a similar proportion of sputum eosinophils (3%) and fraction of expired nitric oxide (50 mL/s; 35 ppb). Both current smokers and exsmokers had reduced serum specific IgE levels to several common environmental allergens.

CONCLUSION

Current smokers with severe asthma exhibit worse clinical and health care outcomes compared with exsmokers and never smokers with severe asthma. Their inflammatory profiles in sputum and blood differ.

Effect of montelukast for treatment of asthma in cigarette smokers

OBJECTIVE

Many asthmatic patients are unable to quit cigarettes; therefore information is needed on treatment options for smokers. This study evaluates 10 mg/d montelukast and 250 μg of fluticasone propionate twice daily, each compared with placebo, in patients with self-reported active smoking (unable to quit) and asthma.

METHODS

Patients (ages 18-55 years, with asthma [≥1 year], FEV1 of 60% to 90% of predicted value, airway reversibility [≥12%], and self-reported active smoking [≥0.5 to ≤2 packs per day]) were randomized (after a 3-week, single-blind, placebo, run-in period) to 1 of 3 parallel, 6-month, double-blind treatment arms. The primary efficacy end point was the percentage of days with asthma control during treatment. Adverse experiences (AEs) were also evaluated.

RESULTS

There were 347, 336, and 336 patients randomized to montelukast, fluticasone, and placebo, respectively. The mean percentage of days with asthma control over 6 months of treatment was 45% (montelukast, P < .05 vs placebo), 49% (fluticasone, P < .001 vs placebo), and 39% (placebo); the difference between montelukast and fluticasone was not significant (P = .14). Patients with a smoking history of ≤11 pack years (the median value) tended to show more benefit with fluticasone, whereas those with a smoking history of >11 pack years tended to show more benefit with montelukast. AEs occurred in similar proportions among treatment groups.

CONCLUSIONS

In a population of asthmatic patients actively smoking cigarettes, both 10 mg/d montelukast and 250 μg of fluticasone propionate twice daily significantly increased the mean percentage of days with asthma control compared with placebo.

Asthma and aerobic exercise: a review of the empirical literature

OBJECTIVE

The purpose of the present article was to provide a comprehensive review of the empirical literature on the association between asthma and aerobic exercise among adults.

METHODS

A literature search was conducted utilizing electronic search engines (i.e., PsycINFO and PubMed) using the following keyword algorithms: asthma AND (exercise OR physical activity).

RESULTS

These searches resulted in approximately 5665 citations. Only results that were directly relevant were included in the present review.

CONCLUSIONS

Overall, empirical evidence suggests that (1) individuals with asthma are less likely to engage in physical activity than those without asthma, (2) individuals with asthma are not biased in their subjective reporting of symptoms during aerobic exercise, (3) physical inactivity among individuals with asthma is associated with negative health consequences and increased asthma-related difficulties, and (4) regular aerobic exercise improves asthma symptom management, lung function, and mental health.

Physical activity and asthma: a systematic review and meta-analysis

INTRODUCTION

This review aims to give an overview of available published evidence concerning the association between physical activity and asthma in children, adolescents and adults.

METHODS

We included all original articles in which both physical activity and asthma were assessed in case-control, cross-sectional or longitudinal (cohort) studies. Excluded were studies concerning physical fitness, studies in athletes, therapeutic or rehabilitation intervention studies such as physical training or exercise in asthma patients. Methodological quality of the included articles was assessed according to the Newcastle-Ottawa Scale (NOS).

RESULTS

A literature search was performed until June 2011 and resulted in 6,951 publications derived from PubMed and 1,978 publications from EMBASE. In total, 39 studies met the inclusion criteria: 5 longitudinal studies (total number of subjects n = 85,117) with physical activity at baseline as exposure, and asthma incidence as outcome. Thirty-four cross-sectional studies (n = 661,222) were included. Pooling of the longitudinal studies showed that subjects with higher physical activity levels had lower incidence of asthma (odds ratio 0.88 (95% CI: 0.77-1.01)). When restricting pooling to the 4 prospective studies with moderate to good study quality (defined as NOS≥5) the pooled odds ratio only changed slightly (0.87 (95% CI: 0.77-0.99)). In the cross-sectional studies, due to large clinical variability and heterogeneity, further statistical analysis was not possible.

CONCLUSIONS

The available evidence indicates that physical activity is a possible protective factor against asthma development. The heterogeneity suggests that possible relevant effects remain hidden in critical age periods, sex differences, or extremes of levels of physical activity (e.g. sedentary). Future longitudinal studies should address these issues.

Therapeutic options for severe asthma

As the overall prevalence of asthma has escalated in the past decades, so has the population of patients with severe asthma. This condition is often difficult to manage due to the relative limitation of effective therapeutic options for the physician and the social and economic burden of the disease on the patient. Management should include an evaluation and elimination of modifiable risk factors such as smoking, allergen exposure, obesity and non-adherence, as well as therapy for co-morbidities like gastro-esophageal reflux disease and obstructive sleep apnea. Current treatment options include conventional agents such as inhalational corticosteroids, long acting β(2) agonists, leukotriene antagonists, and oral corticosteroids. Less conventional treatment options include immunotherapy with methotrexate, cyclosporine and tacrolimus, biological drugs like monoclonal antibodies, tumor necrosis factor-α blockers and oligonucleotides, phosphodiesterase inhibitors, antimicrobials and bronchial thermoplasty.

Higher prevalence of obesity among children with asthma

The aim of this study is to investigate the association between childhood obesity and asthma, and whether this relationship varies by race/ethnicity. For this population-based, cross-sectional study, measured weight and height, and asthma diagnoses were extracted from electronic medical records of 681,122 patients aged 6-19 years who were enrolled in an integrated health plan 2007-2009. Weight class was assigned based on BMI-for-age. Overall, 18.4% of youth had a history of asthma and 10.9% had current asthma. Adjusted odds of current asthma for overweight, moderately obese, and extremely obese youth relative to those of normal weight were 1.22 (95% confidence interval (CI): 1.20, 1.24), 1.37 (95% CI: 1.34, 1.40), and 1.68 (95% CI: 1.64, 1.73), respectively (P trend < 0.001). Black youth are nearly twice as likely (adjusted odds ratio (OR) = 1.93, 95% CI: 1.89, 1.99), and Hispanic youth are 25% less likely (adjusted OR = 0.75, 95% CI: 0.74, 0.77), to have current asthma than to non-Hispanic white youth. However, the relationship between BMI and asthma was strongest in Hispanic and weakest in black youth. Among youth with asthma, increasing body mass was associated with more frequent ambulatory and emergency department visits, as well as increased inhaled and oral corticosteroid use. In conclusion, overweight, moderate, and extreme obesity are associated with higher odds of asthma in children and adolescents, although the association varies widely with race/ethnicity. Increasing BMI among youth with asthma is associated with higher consumption of corticosteroids and emergency department visits.

Results from a community-based program evaluating the effect of changing smoking status on asthma symptom control

Background

Cigarette smoking has been associated with accelerated decline in lung function, increased health services use and asthma severity in patients with asthma. Previous studies have provided insight into how smoking cessation improves lung function among asthma patients, however, fail to provide measurable asthma symptom-specific outcomes after smoking cessation. The objective of this study was to measure the effect of changing smoking status on asthma symptom control and health services use in adults with asthma.

Methods

The study was conducted in eight primary care practices across Ontario, Canada participating in a community-based, participatory, and evidence-based Asthma Care Program. Patients aged 18 to 55 identified with physician-diagnosed mild to moderate asthma were recruited. In addition to receiving clinical asthma care, participants were administered a questionnaire at baseline and 12-month follow-up visits to collect information on demographics, smoking status, asthma symptoms and routine health services use. The effect of changing smoking status on asthma symptom control was compared between smoking groups using Chi-square and Fisher’s exact tests where appropriate. Mixed effect models were used to measure the impact of the change in smoking status on asthma symptom and health services use while adjusting for covariates.

Results

This study included 519 patients with asthma; 11% of baseline smokers quit smoking while 4% of baseline non-smokers started smoking by follow-up. Individuals who quit smoking had 80% lower odds of having tightness in the chest (Odds ratio (OR) = 0.21, 95% CI: 0.06, 0.82) and 76% lower odds of night-time symptoms (OR = 0.24, 95% CI: 0.07, 0.85) compared to smokers who continued to smoke. Compared to those who remained non-smokers, those who had not been smoking at baseline but self-reported as current smoker at follow-up had significantly higher odds of chest tightness (OR = 1.36, 95% CI: 1.10, 1.70), night-time symptoms (OR = 1.55, 95% CI: 1.09, 2.20), having an asthma attack in the last six months (OR = 1.43, 95% CI: 1.17, 1.75) and visiting a walk-in clinic for asthma (OR = 4.57, 95% CI: 1.44, 14.49).

Conclusions

This study provides practitioners measurable and clinically important findings that associate smoking cessation with improved asthma control. Health practitioners and asthma programs can use powerful education messages to emphasize the benefits of smoking cessation as a priority to current smokers.

Improved patient outcome with smoking cessation: when is it too late?

Smoking is the leading modifiable risk factor for chronic obstructive pulmonary disease (COPD), cardiovascular disease (CVD), and lung cancer. Smoking cessation is the only proven way of modifying the natural course of COPD. It is also the most effective way of reducing the risk for myocardial infarction and lung cancer. However, the full benefits of tobacco treatment may not be realized until many years of abstinence. All patients with COPD, regardless of severity, appear to benefit from tobacco treatment. Similarly, patients with recent CVD events also benefit from tobacco treatment. The risk of total mortality and rate of recurrence of lung cancer is substantially lower in smokers who manage to quit smoking following the diagnosis of early stage lung cancer or small cell lung cancer. Together, these data suggest that tobacco treatment is effective both as a primary and a secondary intervention in reducing total morbidity and mortality related to COPD, CVD, and lung cancer. In this paper, we summarize the evidence for tobacco treatment and the methods by which smoking cessation can be promoted in smokers with lung disease.

Vitamin D deficiency causes deficits in lung function and alters lung structure

RATIONALE

The prevalence of vitamin D deficiency is increasing and has been linked to obstructive lung diseases including asthma and chronic obstructive pulmonary disease. Recent studies suggest that vitamin D deficiency is associated with reduced lung function. The relationship between vitamin D deficiency and lung function is confounded by the association between physical activity levels and vitamin D status. Thus, causal data confirming a relationship between vitamin D and lung function are lacking.

OBJECTIVES

To determine if vitamin D deficiency alters lung structure and function.

METHODS

A physiologically relevant BALB/c mouse model of vitamin D deficiency was developed by dietary manipulation. Offspring from deficient and replete colonies of mice were studied for somatic growth, lung function, and lung structure at 2 weeks of age.

MEASUREMENTS AND MAIN RESULTS

Lung volume and function were measured by plethysmography and the forced oscillation technique, respectively. Lung structure was assessed histologically. Vitamin D deficiency did not alter somatic growth but decreased lung volume. There were corresponding deficits in lung function that could not be entirely explained by lung volume. The volume dependence of lung mechanics was altered by deficiency suggesting altered tissue structure. However, the primary histologic difference between groups was lung size rather than an alteration in architecture.

CONCLUSIONS

Vitamin D deficiency causes deficits in lung function that are primarily explained by differences in lung volume. This study is the first to provide direct mechanistic evidence linking vitamin D deficiency and lung development, which may explain the association between obstructive lung disease and vitamin D status.

Effect of Smoking on the Association Between Environmental Triggers and Asthma Severity Among Adults in New England

To identify environmental triggers associated with asthma severity and the potential modifying effect of cigarette smoke, the authors examined the relationship between sociodemographic characteristics, controller medication use, environmental triggers, and actions taken to reduce triggers on asthma severity among adults (≥18 years) residing in New England using the Behavior Risk Factor Surveillance Survey (BRFSS) Asthma Call-Back data. Asthma severity was categorized as intermittent, mild persistent, moderate persistent, and severe persistent according to the National Asthma Education and Prevention Program guidelines. In weighted logistic regression models, asthma severity was analyzed for 3075 adults with active asthma in Connecticut, Massachusetts, Maine, New Hampshire, and Vermont from 2006 to 2007. The odds of more severe asthma were 1.8 for smokers as compared with nonsmokers (95% confidence interval [CI] = 1.1, 3.1). Among current smokers, the odds of more severe asthma among those who were exposed to wood stoves was 2.4 (95% CI = 1.1, 5.7) as compared with those who were not exposed to wood stoves. Among nonsmokers, those who had a high school education or less (odds ratio [OR] = 2.0, 95% CI = 1.2, 3.3), had some college or technical school education (OR = 2.1, 95% CI = 1.2, 3.7), or had any comorbidity factors such as chronic obstructive pulmonary disease, emphysema, or bronchitis (OR = 2.5, 95% CI = 1.6, 3.8) were significantly associated with more severe asthma. Furthermore, the odds for more severe asthma were 2.1 (95% CI = 1.1, 4.0) among nonsmokers who were exposed to environmental tobacco smoke (ETS) as compared with those who were not exposed to ETS. The effect of environmental triggers on asthma severity differs among smokers and nonsmokers, even after controlling for sociodemographic factors, medication use, and actions taken to reduce triggers. Targeting smokers with asthma and making modifications to the environment may be important for reducing asthma severity among a high-risk population.

Asthma and cigarette smoking: a review of the empirical literature

The purpose of this review paper is to present and evaluate the empirical literature on the association between asthma and cigarette smoking. The authors conducted a literature search utilizing electronic search engines (i.e., PsycINFO and MEDLINE) to examine databases using the following key word algorithms: smoking OR nicotine OR tobacco AND asthma. Only articles that focused on active tobacco smoking and analyzed groups with asthma patients only were examined in the present review. Overall, empirical evidence suggests that (1) smoking is more prevalent among individuals with asthma than those without; (2) smoking is a risk candidate for the development of asthma; (3) smoking is associated with decreased asthma control and increased risk of mortality and asthma attacks and exacerbations; (4) smokers with and without asthma may have different risk factors for smoking onset as well as different smoking motives and outcome expectancies; and (5) smoking cessation is associated with improvements in lung functioning and asthma symptoms. Future work in this domain of study will lead to clinically relevant health care advances as well as the development of theoretically driven, methodologically diverse lines of research exploring asthma-smoking comorbidity issues.

Challenges of treating asthma in people who smoke

Cigarette smoking is common in asthma and is associated with poor symptom control and a reduced therapeutic response to inhaled and oral corticosteroids as compared with nonsmokers with asthma. This review examines the range of adverse health effects of smoking in asthma, the inflammatory mechanisms that may influence the efficacy of current drugs and discusses potential future therapeutic directions.

Baseline characteristics of patients enrolled in EXCELS: a cohort study

BACKGROUND

The Epidemiologic Study of Xolair (omalizumab): Evaluating Clinical Effectiveness and Long-term Safety in Patients with Moderate-to-Severe Asthma (EXCELS) is a unique opportunity to evaluate the prospective, long-term clinical safety and effectiveness of the anti-IgE antibody omalizumab (Xolair) in real-world clinical practice.

OBJECTIVES

To describe the study design and study cohorts of EXCELS at baseline and to compare the characteristics of this population with other large asthma cohorts.

METHODS

Patients with moderate-to-severe persistent asthma and a positive skin test result or in vitro reactivity to a perennial aeroallergen were eligible for EXCELS. Two cohorts of patients with asthma were enrolled: those treated with omalizumab and those not treated with omalizumab. We analyzed baseline demographic and clinical characteristics, including asthma history and control and allergy history.

RESULTS

Large proportions of patients enrolled in EXCELS had historically severe and poorly or not well-controlled asthma at the time of enrollment, objective evidence of airway obstruction, a history of long-term oral corticosteroid use, and/or other allergic disorders. Minor differences were observed between the omalizumab and nonomalizumab cohorts. Our total patient cohort was generally similar to other large cohorts. In a subgroup analysis, patients who had received omalizumab within 7 days before enrollment had more severe asthma and greater degrees of impairment at baseline than nonomalizumab patients.

CONCLUSIONS

This study of baseline characteristics in EXCELS offers a unique opportunity to better understand the history of allergic patients with moderate-to-severe asthma in a real-world treatment setting. This analysis of EXCELS baseline data sets the foundation for long-term assessment of the safety and effectiveness of omalizumab.

Association between obesity and asthma in US children and adolescents

BACKGROUND

To explore the association between obesity and asthma in US children and adolescents with adjustment of other structural and behavioral factors.

METHOD

Prevalence and associated risk factors of asthma were explored in 102,273 children and adolescents in the National Survey of Children's Health (2003-2004). Subgroup analysis was performed for subjects of 0-6 year-old, 7-12 year-old, and 13-17 year-old. Crude and adjusted odds ratios for the potential risk factors were examined in univariate and multivariate logistic regressions.

RESULTS

The overall prevalence of obesity was 24.5% and that of asthma was 12.5%. The adjusted odds ratio of asthma with obesity remains significantly bigger than 1 for children in the 7-12 and the 13-17 year-old age-groups. Gender and race were significantly associated with asthma in all age groups. The two parent family structure showed significant protectiveness against asthma with children in the 0-6 year-old age group. Poverty was positively associated with asthma in the 7-12 years old age group. Having a smoker in the household increased the odds of asthma by 29% and 23.5% in the 0-6 and 13-17 year-old age-groups, respectively. Higher education level of the parents and access to healthcare showed positive association with asthma in the 13-17 year-old age group.

CONCLUSION

Gender and race were significantly associated with asthma. In the 13-17 year-old age-groups, obesity, household education level, healthcare coverage, and household smoking were positively associated with asthma. Further studies should characterize how the family structure and household education level influence childhood asthma in 0-6 and 13-17 year-old age-groups respectively.

CXCL5 drives obesity to diabetes, and further

We have recently shown that the CXCL5 chemokine is secreted by adipose tissue in the obese state. We demonstrated that adipose tissue-derived CXCL5 mediates insulin resistance in muscle. We speculate in this paper that CXCL5 could also mediate other obesity, and diabetes-derived pathologies, such as cardiovascular disease, retinopathy, or inflammatory bowel disease. In this scenario CXCL5 targeted therapy would prevent not only the development of type II diabetes in obese subjects, but also several other obesity-related co morbidities. Finally we propose to analyze the CXCL5 gene to find particular polymorphisms that could predict the development of type II diabetes in obese subjects.

Asthma in smokers: challenges and opportunities

PURPOSE OF REVIEW

Cigarette smoking in asthma is associated with poor symptom control and reduced sensitivity to corticosteroids. We summarize recent evidence supporting the adverse effects of smoking in asthma and consider strategies to manage these patients.

RECENT FINDINGS

Smokers have more severe symptoms and are more likely to be admitted to hospital due to poorly controlled asthma compared with nonsmokers with asthma. Possible causes of reduced sensitivity to inhaled corticosteroids in smokers with asthma are noneosinophilic airway inflammation, impaired glucocorticoid receptor function, and/or reduced histone deacetylase activity. Smoking cessation improves asthma control, but quit rates are low. The optimal drug therapy for smokers with asthma is not established due, in part, to the small number of clinical trials performed in these patients. Preliminary data, however, suggest that leukotriene-receptor antagonists may have a beneficial effect in smokers with mild asthma.

SUMMARY

Cigarette smoking in asthma is a risk factor for poor asthma control and reduced sensitivity to corticosteroids. Every effort should be made to encourage individuals with asthma who smoke to quit. Clinical trials are required to identify therapies that restore corticosteroid sensitivity or directly improve symptom control in individuals with asthma who are unable to stop smoking.

The association of BMI and sedentary time with respiratory symptoms and asthma in 5th grade schoolchildren in Kaohsiung, Taiwan

This study aimed to evaluate the association of body fatness and sedentary status with asthma and respiratory symptoms in schoolchildren in Kaohsiung, Taiwan. A questionnaire study elicited episodes of respiratory symptoms and data on lifestyle and anthropometric parameters in 1329 5th grade schoolchildren. Results showed that 12.4% of boys and 9.5% of girls had physician-diagnosed asthma, whereas 15.1% of boys and 12.4% of girls had suspected asthma. Significantly greater proportions of boys had non-exercise-induced respiratory symptoms than girls (p < 0.05). The number of respiratory symptoms was positively correlated with TV-watching time per day and self-reported sedentary time per weekend-day in girls (p < 0.05). Underweight was positively associated with one of the seven respiratory symptoms in girls (p < 0.05). At risk of overweight was positively associated with two of the seven respiratory symptoms in boys and one of the seven respiratory symptoms in girls (all p < 0.05). The risk of having physician-diagnosed asthma and suspected asthma increased 93% and 72%, respectively, in schoolchildren at risk of overweight (p < 0.05). Overweight was associated with a 78% increase in physician-diagnosed asthma (adjusted odd ratio (aOR) = 1.78, 95% CI = 1.08-2.91, p < 0.05). Higher sedentary time was significantly associated with more occurrences of one of the seven respiratory symptoms in girls (aOR = 1.05, 95% CI = 1.00-1.11, p < 0.05). Higher body mass index (BMI) was significantly correlated with longer TV-watching time per day in girls and longer self-reported sedentary time per weekday in boys (p < 0.05). In summary, schoolchildren who are at risk of overweight or overweight and/or have more sedentary time have increased risk of respiratory symptoms and asthma. Weight and sedentary statuses of schoolchildren can affect their respiratory health.