Asthma mortality in U.S. Hispanics of Mexican, Puerto Rican, and Cuban heritage, 1990-1995

Asthma morbidity measures across Black ethnic subgroups

BACKGROUND

Black adults are disproportionately affected by asthma and are often considered a homogeneous group in research studies despite cultural and ancestral differences.

OBJECTIVE

We sought to determine if asthma morbidity differs across adults in Black ethnic subgroups.

METHODS

Adults with moderate-severe asthma were recruited across the continental United States and Puerto Rico for the PREPARE (PeRson EmPowered Asthma RElief) trial. Using self-identifications, we categorized multiethnic Black (ME/B) participants (n = 226) as Black Latinx participants (n = 146) or Caribbean, continental African, or other Black participants (n = 80). African American (AA/B) participants (n = 518) were categorized as Black participants who identified their ethnicity as being American. Baseline characteristics and retrospective asthma morbidity measures (self-reported exacerbations requiring systemic corticosteroids [SCs], emergency department/urgent care [ED/UC] visits, hospitalizations) were compared across subgroups using multivariable regression.

RESULTS

Compared with AA/B participants, ME/B participants were more likely to be younger, residing in the US Northeast, and Spanish speaking and to have lower body mass index, health literacy, and <1 comorbidity, but higher blood eosinophil counts. In a multivariable analysis, ME/B participants were significantly more likely to have ED/UC visits (incidence rate ratio [IRR] = 1.34, 95% CI = 1.04-1.72) and SC use (IRR = 1.27, 95% CI = 1.00-1.62) for asthma than AA/B participants. Of the ME/B subgroups, Puerto Rican Black Latinx participants (n = 120) were significantly more likely to have ED/UC visits (IRR = 1.64, 95% CI = 1.22-2.21) and SC use for asthma (IRR = 1.43, 95% CI = 1.06-1.92) than AA/B participants. There were no significant differences in hospitalizations for asthma among subgroups.

CONCLUSIONS

ME/B adults, specifically Puerto Rican Black Latinx adults, have higher risk of ED/UC visits and SC use for asthma than other Black subgroups.

Immunogenetics and pharmacogenetics of allergic asthma in Africa

Asthma is a common chronic condition in children and in an African setting is often highly prevalent in urban areas as compared to rural areas. Asthma is a heritable disease and the genetic risk is often exacerbated by unique localised environmental factors. The Global Initiative for Asthma (GINA) recommendation for the control of asthma includes inhaled corticosteroids (ICS) alone or together with short-acting β₂-agonists (SABA) or long-acting β₂-agonists (LABA). While these drugs can relieve asthma symptoms, there is evidence of reduced efficacy in people of African ancestry. Whether this is due to immunogenetics, genomic variability in drug metabolising genes (pharmacogenetics) or genetics of asthma-related traits is not well defined. Pharmacogenetic evidence of first-line asthma drugs in people of African ancestry is lacking and is further compounded by the lack of representative genetic association studies in the continent. In this review, we will discuss the paucity of data related to the pharmacogenetics of asthma drugs in people of African ancestry, mainly drawing from African American data. We will further discuss how this gap can be bridged to improve asthma health outcomes in Africa.

Caribbean Latinx with moderate-severe asthma bear greater asthma morbidity than other Latinx

BACKGROUND

Hispanic/Latinx (HL) ethnicity encompasses racially and culturally diverse subgroups. Studies suggest that Puerto Ricans (PR) may bear greater asthma-related morbidity than Mexicans, but these were conducted in children or had limited clinical characterization.

OBJECTIVES

This study sought to determine whether disparities in asthma morbidity exist among HL adult subgroups.

METHODS

Adults with moderate-severe asthma were recruited from US clinics, including from Puerto Rico, for the Person Empowered Asthma Relief (PREPARE) trial. Considering the shared heritage between PR and other Caribbean HL (Cubans and Dominicans [C&D]), the investigators compared baseline self-reported clinical characteristics between Caribbean HL (CHL) (PR and C&D: n = 457) and other HLs (OHL) (Mexicans, Spaniards, Central/South Americans; n = 141), and between CHL subgroups (C&D [n = 56] and PR [n = 401]). This study compared asthma morbidity measures (self-reported exacerbations requiring systemic corticosteroids, emergency department/urgent care (ED/UC) visits, hospitalizations, health care utilization) through negative binomial regression.

RESULTS

CHL compared to OHL were similar in age, body mass index, poverty status, blood eosinophils, and fractional exhaled nitric oxide but were prescribed more asthma controller therapies. Relative to OHL, CHL had significantly increased odds of asthma exacerbations (odds ratio [OR]: 1.84; 95% CI: 1.4-2.4), ED/UC visits (OR: 1.88; 95% CI: 1.4-2.5), hospitalization (OR: 1.98; 95% CI: 1.06-3.7), and health care utilization (OR: 1.91; 95% CI: 1.44-2.53). Of the CHL subgroups, PR had significantly increased odds of asthma exacerbations, ED/UC visits, hospitalizations, and health care utilization compared to OHL, whereas C&D only had increased odds of exacerbations compared to OHL. PR compared to C&D had greater odds of ED/UC and health care utilization.

CONCLUSIONS

CHL adults, compared with OHL, adults reported nearly twice the asthma morbidity; these differences are primarily driven by PR. Novel interventions are needed to reduce morbidity in this highly impacted population.

Racial Inequities in Asthma Care

Racial inequities in asthma care are evolving as a recognized factor in long-standing inequities in asthma outcomes (e.g., hospitalization and mortality). Little research has been conducted regarding the presence or absence of racial inequities among patients seen in asthma specialist settings, this is an important area of future research given that asthma specialist care is recommended for patients experiencing the poor asthma outcomes disproportionately experienced by Black and Hispanic patients. This study provides a systematic review of racial asthma care inequities in asthma epidemiology, clinical assessment, medication prescription, and asthma specialist referral practices.

Socioeconomic status associates with worse asthma morbidity among Black and Latinx adults

BACKGROUND

Asthma disproportionately affects African American/Black (AA/B) and Hispanic/Latinx (H/L) patients and individuals with low socioeconomic status (SES), but the relationship between SES and asthma morbidity within these racial/ethnic groups is inadequately understood.

OBJECTIVE

To determine the relationship between SES and asthma morbidity among AA/B and H/L adults with moderate to severe asthma using multidomain SES frameworks and mediation analyses.

METHODS

We analyzed enrollment data from the PeRson EmPowered Asthma RElief randomized trial, evaluating inhaled corticosteroid supplementation to rescue therapy. We tested for direct and indirect relationships between SES and asthma morbidity using structural equation models. For SES, we used a latent variable defined by poverty, education, and unemployment. For asthma morbidity, we used self-reported asthma exacerbations in the year before enrollment (corticosteroid bursts, emergency room/urgent care visits, or hospitalizations), and Asthma Control Test scores. We tested for mediation via health literacy, perceived stress, and self-reported discrimination. All models adjusted for age, sex, body mass index, ethnicity, and comorbidities.

RESULTS

Among 990 AA/B and H/L adults, low SES (latent variable) was directly associated with hospitalizations (β = 0.24) and worse Asthma Control Test scores (β = 0.20). Stress partially mediated the relationship between SES and increased emergency room/urgent care visits and worse asthma control (β = 0.03 and = 0.05, respectively). Individual SES domains were directly associated with asthma morbidity. Stress mediated indirect associations between low educational attainment and unemployment with worse asthma control (β = 0.05 and = 0.06, respectively).

CONCLUSIONS

Lower SES is directly, and indirectly through stress, associated with asthma morbidity among AA/B and H/L adults. Identification of stressors and relevant management strategies may lessen asthma-related morbidity among these populations.

Reliever-Triggered Inhaled Glucocorticoid in Black and Latinx Adults with Asthma

BACKGROUND

Black and Latinx patients bear a disproportionate burden of asthma. Efforts to reduce the disproportionate morbidity have been mostly unsuccessful, and guideline recommendations have not been based on studies in these populations.

METHODS

In this pragmatic, open-label trial, we randomly assigned Black and Latinx adults with moderate-to-severe asthma to use a patient-activated, reliever-triggered inhaled glucocorticoid strategy (beclomethasone dipropionate, 80 μg) plus usual care (intervention) or to continue usual care. Participants had one instructional visit followed by 15 monthly questionnaires. The primary end point was the annualized rate of severe asthma exacerbations. Secondary end points included monthly asthma control as measured with the Asthma Control Test (ACT; range, 5 [poor] to 25 [complete control]), quality of life as measured with the Asthma Symptom Utility Index (ASUI; range, 0 to 1, with lower scores indicating greater impairment), and participant-reported missed days of work, school, or usual activities. Safety was also assessed.

RESULTS

Of 1201 adults (603 Black and 598 Latinx), 600 were assigned to the intervention group and 601 to the usual-care group. The annualized rate of severe asthma exacerbations was 0.69 (95% confidence interval [CI], 0.61 to 0.78) in the intervention group and 0.82 (95% CI, 0.73 to 0.92) in the usual-care group (hazard ratio, 0.85; 95% CI, 0.72 to 0.999; P = 0.048). ACT scores increased by 3.4 points (95% CI, 3.1 to 3.6) in the intervention group and by 2.5 points (95% CI, 2.3 to 2.8) in the usual-care group (difference, 0.9; 95% CI, 0.5 to 1.2); ASUI scores increased by 0.12 points (95% CI, 0.11 to 0.13) and 0.08 points (95% CI, 0.07 to 0.09), respectively (difference, 0.04; 95% CI, 0.02 to 0.05). The annualized rate of missed days was 13.4 in the intervention group and 16.8 in the usual-care group (rate ratio, 0.80; 95% CI, 0.67 to 0.95). Serious adverse events occurred in 12.2% of the participants, with an even distribution between the groups.

CONCLUSIONS

Among Black and Latinx adults with moderate-to-severe asthma, provision of an inhaled glucocorticoid and one-time instruction on its use, added to usual care, led to a lower rate of severe asthma exacerbations. (Funded by the Patient-Centered Outcomes Research Institute and others; PREPARE ClinicalTrials.gov number, NCT02995733.).

Metabolomic Associations of Asthma in the Hispanic Community Health Study/Study of Latinos

Asthma disproportionally affects Hispanic and/or Latino backgrounds; however, the relation between circulating metabolites and asthma remains unclear. We conducted a cross-sectional study associating 640 individual serum metabolites, as well as twelve metabolite modules, with asthma in 3347 Hispanic/Latino background participants (514 asthmatics, 15.36%) from the Hispanic/Latino Community Health Study/Study of Latinos. Using survey logistic regression, per standard deviation (SD) increase in 1-arachidonoyl-GPA (20:4) was significantly associated with 32% high odds of asthma after accounting for clinical risk factors (p = 6.27 × 10−5), and per SD of the green module, constructed using weighted gene co-expression network, was suggestively associated with 25% high odds of asthma (p = 0.006). In the stratified analyses by sex and Hispanic and/or Latino backgrounds, the effect of 1-arachidonoyl-GPA (20:4) and the green module was predominantly observed in women (OR = 1.24 and 1.37, p < 0.001) and people of Cuban and Puerto-Rican backgrounds (OR = 1.25 and 1.27, p < 0.01). Mutations in Fatty Acid Desaturase 2 (FADS2) affected the levels of 1-arachidonoyl-GPA (20:4), and Mendelian Randomization analyses revealed that high genetically regulated 1-arachidonoyl-GPA (20:4) levels were associated with increased odds of asthma (p < 0.001). The findings reinforce a molecular basis for asthma etiology, and the potential causal effect of 1-arachidonoyl-GPA (20:4) on asthma provides an opportunity for future intervention.

Toward a fine-scale population health monitoring system

Understanding population health disparities is an essential component of equitable precision health efforts. Epidemiology research often relies on definitions of race and ethnicity, but these population labels may not adequately capture disease burdens and environmental factors impacting specific sub-populations. Here, we propose a framework for repurposing data from electronic health records (EHRs) in concert with genomic data to explore the demographic ties that can impact disease burdens. Using data from a diverse biobank in New York City, we identified 17 communities sharing recent genetic ancestry. We observed 1,177 health outcomes that were statistically associated with a specific group and demonstrated significant differences in the segregation of genetic variants contributing to Mendelian diseases. We also demonstrated that fine-scale population structure can impact the prediction of complex disease risk within groups. This work reinforces the utility of linking genomic data to EHRs and provides a framework toward fine-scale monitoring of population health.

A randomized, open-label, pragmatic study to assess reliever-triggered inhaled corticosteroid in African American/Black and Hispanic/Latinx adults with asthma: Design and methods of the PREPARE trial

BACKGROUND

Asthma prevalence, morbidity, and mortality disproportionately impact African American/Black (AA/B) and Hispanic/Latinx (H/L) communities. Adherence to daily inhaled corticosteroid (ICS), recommended by asthma guidelines in all but the mildest cases of asthma, is generally poor. As-needed ICS has shown promise as a patient-empowering asthma management strategy, but it has not been rigorously studied in AA/B or H/L patients or in a real-world setting. Design and Aim The PeRson EmPowered Asthma RElief (PREPARE) Study is a randomized, open-label, pragmatic study which aims to assess whether a patient-guided, reliever-triggered ICS strategy called PARTICS (Patient-Activated Reliever-Triggered Inhaled CorticoSteroid) can improve asthma outcomes in AA/B and H/L adult patient populations. In designing and implementing the study, the PREPARE research team has relied heavily on advice from AA/B and H/L Patient Partners and other stakeholders. Methods PREPARE is enrolling 1200 adult participants (600 AA/Bs, 600H/Ls) with asthma. Participants are randomized to PARTICS + Usual Care (intervention) versus Usual Care (control). Following a single in-person enrollment visit, participants complete monthly questionnaires for 15 months. The primary endpoint is annualized asthma exacerbation rate. Secondary endpoints include asthma control; preference-based quality of life; and days lost from work, school, or usual activities. Discussion The PREPARE study features a pragmatic design allowing for the real-world assessment of a patient-centered, reliever-triggered ICS strategy in AA/B and H/L patients. Outcomes of this study have the potential to offer powerful evidence supporting PARTICS as an effective asthma management strategy in patient populations that suffer disproportionately from asthma morbidity and mortality.

Step-Up Therapy in Black Children and Adults with Poorly Controlled Asthma

BACKGROUND

Morbidity from asthma is disproportionately higher among black patients than among white patients, and black patients constitute the minority of participants in trials informing treatment. Data indicate that patients with inadequately controlled asthma benefit more from addition of a long-acting beta-agonist (LABA) than from increased glucocorticoids; however, these data may not be informative for treatment in black patients.

METHODS

We conducted two prospective, randomized, double-blind trials: one involving children and the other involving adolescents and adults. In both trials, the patients had at least one grandparent who identified as black and had asthma that was inadequately controlled with low-dose inhaled glucocorticoids. We compared combinations of therapy, which included the addition of a LABA (salmeterol) to an inhaled glucocorticoid (fluticasone propionate), a step-up to double to quintuple the dose of fluticasone, or both. The treatments were compared with the use of a composite measure that evaluated asthma exacerbations, asthma-control days, and lung function; data were stratified according to genotypic African ancestry.

RESULTS

When quintupling the dose of fluticasone (to 250 μg twice a day) was compared with adding salmeterol (50 μg twice a day) and doubling the fluticasone (to 100 μg twice a day), a superior response occurred in 46% of the children with quintupling the fluticasone and in 46% of the children with doubling the fluticasone and adding salmeterol (P = 0.99). In contrast, more adolescents and adults had a superior response to added salmeterol than to an increase in fluticasone (salmeterol-low-dose fluticasone vs. medium-dose fluticasone, 49% vs. 28% [P = 0.003]; salmeterol-medium-dose fluticasone vs. high-dose fluticasone, 49% vs. 31% [P = 0.02]). Neither the degree of African ancestry nor baseline biomarkers predicted a superior response to specific treatments. The increased dose of inhaled glucocorticoids was associated with a decrease in the ratio of urinary cortisol to creatinine in children younger than 8 years of age.

CONCLUSIONS

In contrast to black adolescents and adults, almost half the black children with poorly controlled asthma had a superior response to an increase in the dose of an inhaled glucocorticoid and almost half had a superior response to the addition of a LABA. (Funded by the National Heart, Lung, and Blood Institute; BARD ClinicalTrials.gov number, NCT01967173.).

Disparities in Mortality of Hispanic Patients with Cystic Fibrosis in the United States. A National and Regional Cohort Study

RATIONALE

Patients of Hispanic origin with cystic fibrosis (CF) are the largest growing minority, representing 8.5% of patients with CF in the United States. No national survival analysis of this group has ever been undertaken.

OBJECTIVES

We aimed to determine whether Hispanic ethnicity within the CF population is associated with worse outcomes and whether any geographic differences exist.

METHODS

Using U.S. Cystic Fibrosis Foundation Patient Registry data from 2010 to 2014, we performed a retrospective cohort analysis comparing survival rates between Hispanics and non-Hispanics using Kaplan-Meier and Cox regression analysis. A subject's residence was categorized into geographic regions based on U.S. Census Bureau data: Northeast, Midwest, West, and South.

MEASUREMENTS AND MAIN RESULTS

A total of 29,637 patients were included in the study; 2,493 identified themselves as Hispanic. Hispanics had a lower survival probability overall, with a mean age of death of 22.4 ± 9.9 years compared with non-Hispanics of 28.1 ± 10.0 years (P < 0.0001). Multivariate Cox proportional hazards modeling revealed that Hispanic patients with CF had a 1.27 times higher rate of death compared with non-Hispanics (95% confidence interval, 1.05-1.53) after adjusting for covariates including age, sex, genetic mutations, bacterial cultures, lung function, body mass index, use of CF respiratory therapies, low socioeconomic status, pancreatic enzyme use, and CF-related diabetes. When analyzed by region, Hispanics in the Midwest, Northeast, and West had shorter median survivals compared with non-Hispanics, which was not demonstrated in the South.

CONCLUSIONS

Patients with CF of Hispanic origin have a higher mortality rate than non-Hispanic patients with CF. This pattern was seen in the Midwest, Northeast, and West but not in the South.

Exacerbation-prone asthma in the context of race and ancestry in Asthma Clinical Research Network trials

BACKGROUND

Minority groups of African descent experience disproportionately greater asthma morbidity compared with other racial groups, suggesting that genetic variation from a common ancestry could influence exacerbation risk.

OBJECTIVE

We evaluated clinical trial measures in the context of self-reported race and genetic ancestry to identify risk factors for asthma exacerbations.

METHODS

One thousand eight hundred forty multiethnic subjects from 12 Asthma Clinical Research Network and AsthmaNet trials were analyzed for incident asthma exacerbations with Poisson regression models that included clinical measures, self-reported race (black, non-Hispanic white, and other), and estimates of global genetic African ancestry in a subgroup (n = 760).

RESULTS

Twenty-four percent of 1840 subjects self-identified as black. Black and white subjects had common risk factors for exacerbations, including a history of 2 or more exacerbations in the previous year and FEV₁ percent predicted values, whereas chronic sinusitis, allergic rhinitis, and gastroesophageal reflux disease were only associated with increased exacerbation risk in black subjects. In the combined multiethnic cohort, neither race (P = .30) nor percentage of genetic African ancestry as a continuous variable associated with exacerbation risk (adjusted rate ratio [RR], 1.26 [95% CI, 0.94-1.70; P = .13]; RR per 1-SD change [32% ancestry], 0.97 [95% CI, 0.78-1.19; P = .74]). However, in 161 black subjects with genetic data, those with African ancestry greater than the median (≥82%) had a significantly greater risk of exacerbation (RR, 3.06 [95% CI, 1.09-8.6; P = .03]).

CONCLUSION

Black subjects have unique risk factors for asthma exacerbations, of which global African genetic ancestry had the strongest effect.

Disparities in complementary alternative medicine use and asthma exacerbation in the United States

Background: Complementary and alternative medicines (CAM) are associated with poor asthma medication adherence, a major risk factor for asthma exacerbation. However, previous studies showed inconsistent relationships between CAM use and asthma control due to small sample sizes, demographic differences across populations studied, and poor differentiation of CAM types.Methods: We examined associations between CAM use and asthma exacerbation using a cross-sectional analysis of the 2012 National Health Interview Survey. We included adults ≥18 years with current asthma (n = 2,736) to analyze racial/ethnic differences in CAM use as well as the association between CAM use and both asthma exacerbation and emergency department (ED) visit for asthma exacerbation across racial/ethnic groups. We ran descriptive statistics and multivariable logistic regressions.Result: Blacks (OR = 0.63 [0.49-0.81]) and Hispanics (OR = 0.66 [0.48-0.92]) had decreased odds of using CAM compared to Whites. Overall, there was no association between CAM use and asthma exacerbation (OR = 0.99 [0.79-1.25]) but the subgroup of 'other complementary approaches' was associated with increased odds of asthma exacerbation among all survey respondents (1.90 [1.21-2.97]), Whites (OR = 1.90 [1.21-2.97]), and Hispanics (OR = 1.43 [0.98-2.09). CAM use was associated with decreased odds of an ED visit for asthma exacerbation (OR = 0.65 [0.45-0.93]). These associations were different among racial/ethnic groups with decreased odds of ED visit among Whites (OR = 0.50 [0.32-0.78]) but no association among Blacks and Hispanics.Conclusion: We found that both CAM use and the association between CAM use and asthma exacerbation varied by racial/ethnic group. The different relationship may arise from how CAM is used to complement or to substitute for conventional asthma management.

Measuring Micrometers of Matter and Inventing Indices: Entangling Social Perception within Discrete and Continuous Measurements of Air Quality

Environmental protection agencies around the globe are establishing different methods for measuring particulates, and then integrating those measurements into a single air quality index with other pollutants. At the same time, scientific inquiry has also shifted to a theory of measurement that incorporates discrete and continuous measurement. This article reviews the relationship between discrete measurements and indices, while also speculating on the way that the continuous measurement of air pollution could stimulate awareness and action. The paper argues that continuous measurement must include the way people of different backgrounds perceive air pollution in their lives. After reviewing the methods of measuring particulates and their inclusion into various indices, the article argues that in order to take action to mitigate the health impacts of air pollution, we must allow for the social perception of air pollution to become entangled within our scientific measurements.

Role of epigenetics and DNA-damage in asthma

PURPOSE OF REVIEW

Although asthma is a common disease worldwide, its pathogenesis remains to be fully elucidated. There is increasing evidence of the interaction between epigenetics, DNA-damage, and environmental allergens in the development of asthma. In this review, we will focus on the role of epigenetics and DNA-damage in asthma.

RECENT FINDINGS

There is growing evidence of environmental allergens, particularly house dust mite, stimulating oxidative DNA damage in airway epithelial cells. The repair of this DNA damage has been implicated in the secretion of Th2 cytokines and the induction of allergic inflammation.

SUMMARY

Studies of the role of epigenetics, DNA-damage, and environmental allergens have begun to reveal the their complex interactions and their roles in the development of asthma. Further study in these areas may lead to novel prevention and treatment approaches.

Psychosocial risk factors and asthma among adults in Puerto Rico

OBJECTIVE

Asthma and psychosocial stressors are common among Puerto Rican adults living in the United States. We estimated the prevalence of current asthma, and examined potential psychosocial risk factors and current asthma, among adults in Puerto Rico.

METHODS

Cross-sectional study of 3,049 Puerto Ricans aged 18-64 years living in Puerto Rico between May 2014 and June 2016. A structured interview was conducted to obtain information on demographics, lifestyle, mental disorders, and respiratory health. Current asthma was defined as self-reported physician-diagnosed asthma and still having asthma. Multivariable logistic regression was used to examine psychosocial risk factors and current asthma.

RESULTS

The estimated prevalence of current asthma was 10.2%. In a multivariable analysis, exposure to violence (odds ratio [OR] for each 1-point increment in a validated scale = 1.14, 95% confidence interval [CI] = 1.07 to 1.21) and a lifetime history of at least one suicide attempt (OR = 3.01, 95% CI = 1.80 to 5.01) were significantly associated with current asthma, independently of major depressive disorder. Moreover, a lifetime history of at least one suicide attempt was associated with co-existing asthma and chronic obstructive pulmonary disease (i.e., asthma-COPD overlap syndrome or ACOS (OR = 9.05, 95% CI = 3.32-24.67).

CONCLUSIONS

Our findings suggest that asthma is a major health problem among adults in Puerto Rico, with psychosocial risk factors playing a significant role in asthma and ACOS. Addressing chronic stressors and mental illness should be part of comprehensive strategies to reduce asthma burden in this population.

Health care access, concentrated poverty, and pediatric asthma hospital care use in California's San Joaquin Valley: A multilevel approach

BACKGROUND

California's San Joaquin Valley is a region with a history of poverty, low health care access, and high rates of pediatric asthma. It is important to understand the potential barriers to care that challenge vulnerable populations.

OBJECTIVE

The objective was to describe pediatric asthma-related utilization patterns in the emergency department (ED) and hospital by insurance coverage as well as to identify contributing individual-level indicators (age, sex, race/ethnicity, and insurance coverage) and neighborhood-level indicators of health care access.

METHODS

This was a retrospective study based on secondary data from California hospital and ED records 2007-2012. Children who used services for asthma-related conditions, were aged 0-14 years, Hispanic or non-Hispanic white, and resided in the San Joaquin Valley were included in the analysis. Poisson multilevel modeling was used to control for individual- and neighborhood-level factors.

RESULTS

The effect of insurance coverage on asthma ED visits and hospitalizations was modified by the neighborhood-level percentage of concentrated poverty (RR = 1.01, 95% CI = 1.01-1.02; RR = 1.03, 95% CI = 1.02-1.04, respectively). The effect of insurance coverage on asthma hospitalizations was completely explained by the neighborhood-level percentage of concentrated poverty.

CONCLUSIONS

Observed effects of insurance coverage on hospital care use were significantly modified by neighborhood-level measures of health care access and concentrated poverty. This suggests not only an overall greater risk for poor children on Medi-Cal, but also a greater vulnerability or response to neighborhood social factors such as socioeconomic status, community cohesiveness, crime, and racial/ethnic segregation.

Population Stratification in Genetic Association Studies

Population stratification (PS) is a primary consideration in studies of genetic determinants of human traits. Failure to control for PS may lead to confounding, causing a study to fail for lack of significant results, or resources to be wasted following false-positive signals. Here, historical and current approaches for addressing PS when performing genetic association studies in human populations are reviewed. Methods for detecting the presence of PS, including global and local ancestry methods, are described. Also described are approaches for accounting for PS when calculating association statistics, such that measures of association are not confounded. Many traits are being examined for the first time in minority populations, which may inherently feature PS. © 2017 by John Wiley & Sons, Inc.

Breastfeeding associated with higher lung function in African American youths with asthma

OBJECTIVE

In the United States, Puerto Ricans and African Americans have lower prevalence of breastfeeding and worse clinical outcomes for asthma compared with other racial/ethnic groups. We hypothesize that the history of breastfeeding is associated with increased forced expiratory volume in 1 second (FEV1) % predicted and reduced asthma exacerbations in Latino and African American youths with asthma.

METHODS

As part of the Genes-environments & Admixture in Latino Americans (GALA II) Study and the Study of African Americans, asthma, Genes & Environments (SAGE II), we conducted case-only analyses in children and adolescents aged 8-21 years with asthma from four different racial/ethnic groups: African Americans (n = 426), Mexican Americans (n = 424), mixed/other Latinos (n = 255), and Puerto Ricans (n = 629). We investigated the association between any breastfeeding in infancy and FEV1% predicted using multivariable linear regression; Poisson regression was used to determine the association between breastfeeding and asthma exacerbations.

RESULTS

Prevalence of breastfeeding was lower in African Americans (59.4%) and Puerto Ricans (54.9%) compared to Mexican Americans (76.2%) and mixed/other Latinos (66.9%; p < 0.001). After adjusting for covariates, breastfeeding was associated with a 3.58% point increase in FEV1% predicted (p = 0.01) and a 21% reduction in asthma exacerbations (p = 0.03) in African Americans only.

CONCLUSION

Breastfeeding was associated with higher FEV1% predicted in asthma and reduced number of asthma exacerbations in African American youths, calling attention to continued support for breastfeeding.

What Ancestry Can Tell Us About the Genetic Origins of Inter-Ethnic Differences in Asthma Expression

Differences in asthma prevalence have been described across different populations, suggesting that genetic ancestry can play an important role in this disease. In fact, several studies have demonstrated an association between African ancestry with increased asthma susceptibility and severity, higher immunoglobulin E levels, and lower lung function. In contrast, Native American ancestry has been shown to have a protective role for this disease. Genome-wide association studies have allowed the identification of population-specific genetic variants with varying allele frequency among populations. Additionally, the correlation of genetic ancestry at the chromosomal level with asthma and related traits by means of admixture mapping has revealed regions of the genome where ancestry is correlated with the disease. In this review, we discuss the evidence supporting the association of genetic ancestry with asthma susceptibility and asthma-related traits, and highlight the regions of the genome harboring ancestry-specific genetic risk factors.

The Effect of Ancestry and Genetic Variation on Lung Function Predictions: What Is "Normal" Lung Function in Diverse Human Populations?

Lung function measures are an invaluable screening test for respiratory health and have been associated with the morbidity and mortality related to different airway disease as well as all-cause mortality. Currently, reference values for spirometric measurements are obtained using equations derived from individual ethnic or racial groups. The rapid expansion of more racially and ethnically diverse populations will challenge current race-based lung function reference equations. Recent international general population studies and ancestry-based genetic studies have found that ancestry and genetic variation are determinants of lung function and have suggested a role for genetic ancestry or gene variants in future lung function reference equations. In this review, we discuss the potential limitations of current lung function reference equations in a global society which is becoming more ethnically, racially, and, thus, genetically diverse. We also focus on how an individual's ancestral background or genetic profile could provide the basis for more accurate, personalized predictions of an individual's baseline lung function.

The effect of parental social support and acculturation on childhood asthma control

OBJECTIVE

There exists large ethnic disparities in asthma among Latino children; Puerto Ricans (PRs) are disproportionately affected, while Mexicans have the lowest prevalence and morbidity. Disparities are poorly understood, however, acculturation and social support are suggested to influence asthma control among children. This study investigated the relationship between acculturation, social support and asthma control among PR and Mexican children and their caregivers.

METHODS

Primary caregiver-child dyads (n = 267) of PR (n = 79) and Mexican (n = 188) descent were recruited from clinics at two inner-city hospitals in Bronx, NY and three clinics in Phoenix, AZ. Children were 5-12 years of age and had a confirmed asthma diagnosis. Dyads completed measures of social support, acculturation and asthma control; logistic regression was used for analysis.

RESULTS

Mexican children had better asthma control than PR children (p < 0.001). PR caregivers were more acculturated than Mexican caregivers (p < 0.05); however, acculturation did not predict control. Across Latino subgroups caregivers' total level of social support predicted better asthma control among children (p < 0.05), and support received from family and friends each independently predicted better control (p < 0.05).

CONCLUSIONS

Results suggest that social support reduces some of the burden associated with asthma management enabling caretakers to better control their children's asthma.

Implications of population structure and ancestry on asthma genetic studies

PURPOSE OF REVIEW

The frequency and severity of asthma differ between different racial and ethnic groups. An understanding of the genetic basis for these differences could constitute future genetic biomarker panels for predicting asthma risk and progression in individuals from different ethnic groups.

RECENT THEMES

The recent mixing of different ancestries during the European colonization of the Americas and the African slave trade has resulted in the complex population structures identified in different ethnic groups. These population structures represent varying degrees of genetic diversity which impacts the allele frequency of individual variants and, thus, how the gene variation is utilized in genetic association studies. In this review, we will discuss the basis for the complex population structures of modern human genomes and the impact of genetic diversity on genetic studies in different ethnic groups. We will also highlight the potential for admixture and rare variant-based genetic studies to identify novel genetic loci for asthma susceptibility and severity.

SUMMARY

The ability to account for the consequences of genetic diversity in different racial and ethnic groups will be critical in developing genetic profiles for personalized or precision medicine approaches tailored to asthmatic patients from different ethnic groups.

Asthma prevalence among Hispanic adults in Puerto Rico and Hispanic adults of Puerto Rican descent in the United States - results from two national surveys

Abstract Objective: To assess whether asthma prevalence differs between Hispanic adults living in Puerto Rico and Hispanic adults of Puerto Rican descent living in the United States.

METHODS

We used 2008-2010 Behavioral Risk Factor Surveillance System data, administered in Puerto Rico for Hispanic adults living in Puerto Rico (Hispanics in Puerto Rico), and 2008-2010 National Health Interview Survey data for Hispanic adults of Puerto Rican descent living in the United States (Puerto Rican Americans). We used 95% confidence intervals (CIs) to compare asthma prevalence between corresponding subgroups; non-overlapping CIs indicate statistical significance. Chi-square test and multivariate logistic regression were used to assess the association between current asthma status and socio-demographic factors and health risk behaviors within each Puerto Rican population.

RESULTS

Current asthma prevalence among Hispanics in Puerto Rico (7.0% [6.4%-7.7%]) was significantly lower than the prevalence among Puerto Rican Americans (15.6% [13.0%-18.1%]). The prevalence among almost all socio-demographic and health risk subgroups of Hispanics in Puerto Rico was significantly lower than the prevalence among the corresponding subgroups of Puerto Rican Americans. Adjusting for potential confounders did not alter the results. Asthma prevalence was significantly associated with obesity among Puerto Rican Americans (adjusted prevalence ratios [aPR]=1.5 [1.1-2.0]), and among Hispanics in Puerto Rico was associated with obesity (aPR=1.6 [1.3-1.9]), smoking (aPR=1.4 [1.1-1.9]) and being female (aPR=1.9 [1.5-2.4]).

CONCLUSION

Asthma was more prevalent among Puerto Rican Americans than Hispanics in Puerto Rico. Although the observed associations did not explain all variations in asthma prevalence between these two populations, they may lay the foundation for future research.

Genetic ancestry influences asthma susceptibility and lung function among Latinos

BACKGROUND

Childhood asthma prevalence and morbidity varies among Latinos in the United States, with Puerto Ricans having the highest and Mexicans the lowest.

OBJECTIVE

To determine whether genetic ancestry is associated with the odds of asthma among Latinos, and secondarily whether genetic ancestry is associated with lung function among Latino children.

METHODS

We analyzed 5493 Latinos with and without asthma from 3 independent studies. For each participant, we estimated the proportion of African, European, and Native American ancestry using genome-wide data. We tested whether genetic ancestry was associated with the presence of asthma and lung function among subjects with and without asthma. Odds ratios (OR) and effect sizes were assessed for every 20% increase in each ancestry.

RESULTS

Native American ancestry was associated with lower odds of asthma (OR = 0.72, 95% CI: 0.66-0.78, P = 8.0 × 10(-15)), while African ancestry was associated with higher odds of asthma (OR = 1.40, 95% CI: 1.14-1.72, P = .001). These associations were robust to adjustment for covariates related to early life exposures, air pollution, and socioeconomic status. Among children with asthma, African ancestry was associated with lower lung function, including both pre- and post-bronchodilator measures of FEV1 (-77 ± 19 mL; P = 5.8 × 10(-5) and -83 ± 19 mL; P = 1.1 x 10(-5), respectively) and forced vital capacity (-100 ± 21 mL; P = 2.7 × 10(-6) and -107 ± 22 mL; P = 1.0 x 10(-6), respectively).

CONCLUSION

Differences in the proportions of genetic ancestry can partially explain disparities in asthma susceptibility and lung function among Latinos.

Effectiveness of a promotora home visitation program for underserved Hispanic children with asthma

OBJECTIVE

Retention in a mobile asthma clinic, the Breathmobile™, of ≥3 visits has previously been shown to be essential for attaining asthma control in underserved children. The objective of this study in primarily Hispanic-American children was to determine the difference in retention between those seen in the Breathmobile™ compared to those receiving an additional promotora-based home visit (HV).

METHODS

Children with asthma in the Breathmobile™ program were evaluated for asthma status and aeroallergen sensitivity. Indication for HV included poor asthma control, educational and environmental control needs. An initial visit consisted of environmental assessment as well as a 3-h interactive educational session covering asthma basics. A follow-up visit 1 month later assessed implementation. The primary outcome measure of retention was ≥6 months in the Breathmobile™ program.

RESULTS

Of the 1007 asthmatic children seen between April 2002 and June of 2005, 136 received HV. These children showed significantly greater retention compared to those without HV with a median number of visits (5 visits versus 2 visits), ≥3 Breathmobile™ visits (86.0% versus 38.8%), median number of days in the program (299 versus 63 days) and percentage of patients in the program ≥6 months (67.8% versus 31.3%) p < 0.001. HV and asthma severity were each independent predictors of retention.

CONCLUSIONS

The addition of a promotora HV program proved effective in providing greater retention in the Breathmobile™ program essential for asthma control. Randomized clinical trials will be needed to show the impact on health care utilization and asthma control.

"Looking out for each other": a qualitative study on the role of social network interactions in asthma management among adult Latino patients presenting to an emergency department

OBJECTIVE

The objective of this study was to identify the types of interactions between asthma patients and their social networks such as close family and friends that influence the management of asthma.

METHODS

Participants were Latino adults presenting for a repeat visit to the emergency department for asthma treatment. Qualitative interviews were conducted with 76 participants. They were asked to describe the experiences of their social networks that have asthma and how interactions with these individuals influenced their own asthma management. Responses were transcribed and analyzed using Grounded Theory as a qualitative analytic approach. Responses were assigned codes; similar codes were grouped into concepts and then categorized to form overarching themes.

RESULTS

Four themes emerged: (1) Perceptions of severity of asthma may be based on the experiences of social networks; (2) Economic factors may contribute to the sharing and borrowing of asthma medications between patients and their social networks; (3) Economic factors may contribute to using home remedies instead of prescribed medications; (4) Social network members may be unaware of the factors that trigger asthma and therefore, contribute to asthma exacerbations.

CONCLUSION

This study identified important social network interactions that may impact asthma management in Latino adults. These results can be used to broaden the current focus of asthma self-management programs to incorporate discussions on the role of social networks. A focus on social network interactions addresses the social epidemiology of asthma and advances our understanding of root causes that may underlie the high prevalence of asthma in many Latino communities.

Whole-genome sequencing of individuals from a founder population identifies candidate genes for asthma

Asthma is a complex genetic disease caused by a combination of genetic and environmental risk factors. We sought to test classes of genetic variants largely missed by genome-wide association studies (GWAS), including copy number variants (CNVs) and low-frequency variants, by performing whole-genome sequencing (WGS) on 16 individuals from asthma-enriched and asthma-depleted families. The samples were obtained from an extended 13-generation Hutterite pedigree with reduced genetic heterogeneity due to a small founding gene pool and reduced environmental heterogeneity as a result of a communal lifestyle. We sequenced each individual to an average depth of 13-fold, generated a comprehensive catalog of genetic variants, and tested the most severe mutations for association with asthma. We identified and validated 1960 CNVs, 19 nonsense or splice-site single nucleotide variants (SNVs), and 18 insertions or deletions that were out of frame. As follow-up, we performed targeted sequencing of 16 genes in 837 cases and 540 controls of Puerto Rican ancestry and found that controls carry a significantly higher burden of mutations in IL27RA (2.0% of controls; 0.23% of cases; nominal p = 0.004; Bonferroni p = 0.21). We also genotyped 593 CNVs in 1199 Hutterite individuals. We identified a nominally significant association (p = 0.03; Odds ratio (OR) = 3.13) between a 6 kbp deletion in an intron of NEDD4L and increased risk of asthma. We genotyped this deletion in an additional 4787 non-Hutterite individuals (nominal p = 0.056; OR = 1.69). NEDD4L is expressed in bronchial epithelial cells, and conditional knockout of this gene in the lung in mice leads to severe inflammation and mucus accumulation. Our study represents one of the early instances of applying WGS to complex disease with a large environmental component and demonstrates how WGS can identify risk variants, including CNVs and low-frequency variants, largely untested in GWAS.

Does the "Hispanic paradox" occur in rheumatoid arthritis? Survival data from a multiethnic cohort

OBJECTIVE

Despite lower socioeconomic status (SES) and higher disease burden, Hispanics in the US paradoxically display equal or lower mortality on average than non-Hispanic whites. Our objective was to determine if the "Hispanic paradox" occurs among patients with rheumatoid arthritis (RA).

METHODS

In a cohort of 706 RA patients, we compared differences in RA severity and comorbidity between Hispanic and non-Hispanic white ethnic groups at baseline. Cox proportional hazards models were used to estimate and compare mortality risk between Hispanics and non-Hispanic whites.

RESULTS

We studied 706 patients with RA, of whom 434 were Hispanic and 272 were non-Hispanic white. Hispanics had significantly lower SES, greater inflammation, as well as higher tender and swollen joint counts. Patients were observed for 6,639 patient-years, during which time 229 deaths occurred by the censoring date (rate 3.4 per 100 person-years; 95% confidence interval 3.0, 3.9). Age- and sex-adjusted mortality was not significantly different between the 2 ethnic groups (hazard ratio [HR] 0.96). After adjustment for comorbidities, RA severity, and level of acculturation, mortality among Hispanics was lower (HR 0.56, P = 0.004).

CONCLUSION

Despite greater severity in most clinical manifestations and lower SES among Hispanics, paradoxically, their mortality was not increased. Further research is needed to understand the mechanisms underlying this survival paradox.

Asthma in Hispanics. An 8-year update

This review provides an update on asthma in Hispanics, a diverse group tracing their ancestry to countries previously under Spanish rule. A marked variability in the prevalence and morbidity from asthma remains among Hispanic subgroups in the United States and Hispanic America. In the United States, Puerto Ricans and Mexican Americans have high and low burdens of asthma, respectively (the "Hispanic Paradox"). This wide divergence in asthma morbidity among Hispanic subgroups is multifactorial, likely reflecting the effects of known (secondhand tobacco smoke, air pollution, psychosocial stress, obesity, inadequate treatment) and potential (genetic variants, urbanization, vitamin D insufficiency, and eradication of parasitic infections) risk factors. Barriers to adequate asthma management in Hispanics include economic and educational disadvantages, lack of health insurance, and no access to or poor adherence with controller medications such as inhaled corticosteroids. Although considerable progress has been made in our understanding of asthma in Hispanic subgroups, many questions remain. Studies of asthma in Hispanic America should focus on environmental or lifestyle factors that are more relevant to asthma in this region (e.g., urbanization, air pollution, parasitism, and stress). In the United States, research studies should focus on risk factors that are known to or may diverge among Hispanic subgroups, including but not limited to epigenetic variation, prematurity, vitamin D level, diet, and stress. Clinical trials of culturally appropriate interventions that address multiple aspects of asthma management in Hispanic subgroups should be prioritized for funding. Ensuring high-quality healthcare for all remains a pillar of eliminating asthma disparities.

Obesity and adiposity indicators, asthma, and atopy in Puerto Rican children

BACKGROUND

Whether adiposity indicators other than body mass index (BMI) should be used in studies of childhood asthma is largely unknown. The role of atopy in "obese asthma" is also unclear.

OBJECTIVES

To examine the relationship among adiposity indicators, asthma, and atopy in Puerto Rican children, and to assess whether atopy mediates the obesity-asthma association.

METHODS

In a study of Puerto Rican children with (n = 351) and without (n = 327) asthma, we measured BMI, percent of body fat, waist circumference, and waist-to-hip ratio. The outcomes studied included asthma, lung function, measures of atopy, and, among cases, indicators of asthma severity or control. We performed mediation analysis to assess the contribution of atopy to the relationship between adiposity and asthma.

RESULTS

BMI, percent of body fat, and waist circumference were associated with increased odds of asthma. Among cases, all 3 measures were generally associated with lung function, asthma severity/control, and atopy; however, there were differences depending on the adiposity indicator analyzed. Atopy considerably mediated the adiposity-asthma association in this population: allergic rhinitis accounted for 22% to 53% of the association with asthma, and sensitization to cockroach mediated 13% to 20% of the association with forced vital capacity and 29% to 42% of the association with emergency department visits for asthma.

CONCLUSIONS

Adiposity indicators are associated with asthma, asthma severity/control, and atopy in Puerto Rican children. Atopy significantly mediates the effect of adiposity on asthma outcomes. Longitudinal studies are needed to further investigate the causal role, if any, of adiposity distribution and atopy on "obese asthma" in childhood.

The influence of Hispanic ethnicity on parent-provider communication about asthma

Research has shown that minority caregivers of children with asthma report poorer communication with health care providers than nonminority caregivers. Less is known about the specific influence of Hispanic ethnicity on parent-provider communication. Our objective was to evaluate the influence of Hispanic ethnicity on parent-provider communication regarding their child's asthma and on caregiver confidence in communicating with their child's provider at a primary care visit. Data were obtained from 166 caregivers of children (2-12 years) with persistent asthma. Caregiver perceptions of provider communication and confidence were evaluated. We found that Hispanic compared to non-Hispanic caregivers reported better communication with providers on several items. Hispanic caregivers also were more likely to indicate full confidence in their ability to communicate with providers. These findings suggest Hispanic caregivers may experience better parent-provider communication than non-Hispanics. Further investigation is needed to assess provider- and clinic-specific factors that may influence communication between minority caregivers and providers.

Pharmacogenetics: implications of race and ethnicity on defining genetic profiles for personalized medicine

Pharmacogenetics is being used to develop personalized therapies specific to subjects from different ethnic or racial groups. To date, pharmacogenetic studies have been primarily performed in trial cohorts consisting of non-Hispanic white subjects of European descent. A "bottleneck" or collapse of genetic diversity associated with the first human colonization of Europe during the Upper Paleolithic period, followed by the recent mixing of African, European, and Native American ancestries, has resulted in different ethnic groups with varying degrees of genetic diversity. Differences in genetic ancestry might introduce genetic variation, which has the potential to alter the therapeutic efficacy of commonly used asthma therapies, such as β2-adrenergic receptor agonists (β-agonists). Pharmacogenetic studies of admixed ethnic groups have been limited to small candidate gene association studies, of which the best example is the gene coding for the receptor target of β-agonist therapy, the β2-adrenergic receptor (ADRB2). Large consortium-based sequencing studies are using next-generation whole-genome sequencing to provide a diverse genome map of different admixed populations, which can be used for future pharmacogenetic studies. These studies will include candidate gene studies, genome-wide association studies, and whole-genome admixture-based approaches that account for ancestral genetic structure, complex haplotypes, gene-gene interactions, and rare variants to detect and replicate novel pharmacogenetic loci.

Association between birthplace and current asthma: the role of environment and acculturation

OBJECTIVES

We evaluated associations between current asthma and birthplace among major racial/ethnic groups in the United States.

METHODS

We used multivariate logistic regression methods to analyze data on 102,524 children and adolescents and 255,156 adults in the National Health Interview Survey (2001-2009).

RESULTS

We found significantly higher prevalence (P < .05) of current asthma among children and adolescents (9.3% vs 5.1%) and adults (7.6% vs 4.7%) born in the 50 states and Washington, DC (US-born), than among those born elsewhere. These differences were among all age groups of non-Hispanic Whites, non-Hispanic Blacks, and Hispanics (excluding Puerto Ricans) and among Chinese adults. Non-US-born adults with 10 or more years of residency in the United States had higher odds of current asthma (odds ratio = 1.55; 95% confidence interval = 1.25, 1.93) than did those who arrived more recently. Findings suggested a similar trend among non-US-born children.

CONCLUSIONS

Current asthma status was positively associated with being born in the United States and with duration of residency in the United States. Among other contributing factors, changes in environment and acculturation may explain some of the differences in asthma prevalence.

The effectiveness of a pictorial asthma action plan for improving asthma control and the quality of life in illiterate women

BACKGROUND

Written asthma action plans are an important part of asthma management, but cannot be used for illiterate people.

OBJECTIVE

The aim of this study was to establish the effectiveness of a pictorial asthma action plan on asthma control, health-related quality of life (HRQoL), and asthma morbidity in a population of illiterate women with asthma.

METHODS

Forty illiterate women with moderate-severe persistent asthma were assigned alternatively to receive either asthma education alone (control group) or asthma education and a pictorial asthma action plan (study group). Asthma control was assessed using the asthma control test (ACT), HRQoL was assessed using the St George's Respiratory Questionnaire (SGRQ), and the frequency of non-scheduled hospital or emergency visits was monitored.

RESULTS

Thirty-four patients completed the study. The ACT and SGRQ scores of both groups improved at every follow-up time point compared with baseline (p < 0.001). The ACT scores at 1 month (22.44 versus 20.75, p = 0.034) and 2 months (23.28 versus 21.81, p = 0.010) were higher in the study group than in the control group, but this was not maintained at 6 months (24.00 versus 23.25, p = 0.069). The SGRQ scores at 6 months were better in the study group (18.12) than in the control group (23.96, p = 0.033). No hospital admissions were recorded for either group.

CONCLUSION

Education provides a significant improvement in asthma control and HRQoL while managing illiterate asthma patients, additionally the pictorial asthma action plan can be a helpful tool for self-medication.

The association between asthma-related emergency department visits and pollen and mold spore concentrations in the Bronx, 2001-2008

BACKGROUND

The incidence of asthma morbidity and mortality is highest among minority inner-city populations. Among New York City's five boroughs, the Bronx has the highest rate of asthma-related hospitalizations and mortality. Outdoor air pollutants have been associated with increased asthma-related ED visits (AREDV) in this borough.

OBJECTIVE

To better understand the contribution of pollen and mold to asthma severity in the Bronx.

METHODS

The numbers of daily adult and pediatric AREDV and asthma-related hospitalizations (ARH) from 2001 to 2008 were obtained from two Bronx hospitals. AREDV and ARH data were acquired retrospectively through the Clinical Looking Glass data analysis software. Daily counts for tree, grass and weed pollen and mold spore counts from March 2001 to October 2008 were obtained from the Armonk counting station. All data were statistically analyzed and graphed as daily values.

RESULTS

There were a total of 42 065 AREDV and 10 132 ARH at both Bronx hospitals. There were spring and winter peaks of increased AREDV. Tree pollen counts significantly correlated with total AREDV (rho = 0.3639, p < 0.001), and pediatric (rho = 0.33, p < 0.001) and adult AREDV (rho = 0.28, p < 0.001). ARH positively correlated with tree pollen counts (Spearman rho = 0.2389, p < 0.001).

CONCLUSIONS

There exists a significant association between spring AREDV and ARH and tree pollen concentrations in a highly urbanized area such as the Bronx. Early anticipation of spring pollen peaks based on ongoing surveillance could potentially guide clinical practice and minimize asthma-related ED visits in the Bronx.

A review of barriers to effective asthma management in Puerto Ricans: cultural, healthcare system and pharmacogenomic issues

BACKGROUND

Among the Hispanic community, Puerto Ricans have the highest prevalence of asthma and manifest the worst outcomes. The expected growth of the Hispanic population in the USA in the next several decades make elimination of disparate care in Puerto Rican asthmatics a matter of national importance. The purpose of this review of the literature (ROL) is to examine a variety of health system, genetic and cultural barriers in the Puerto Rican community which have created disparities in asthma care and outcomes among adult and pediatric Hispanic populations. In addition, this ROL describes several culturally sensitive, community-based educational interventions which can be used as a framework for future projects to improved asthma outcomes.

METHODS

Databases searched included Medline, PubMED, EBSCOhost, PsycINFO, CINAHL, Google Scholar and ERIC. Papers published in English from January 1990 to January 2012 were reviewed.

RESULTS

Health system policies, insurer compensation patterns, clinician attitudes and cultural values/folk remedies in the Puerto Rican community represent barriers to effective asthma management, the use of controller medication and the implementation of educational interventions. In addition, genetic factors involving the beta-2 adrenergic receptor gene, which impair the response to albuterol, appear to contribute to poorer outcomes in Puerto Rican asthmatics. In contrast, several comprehensive, community-based, culturally sensitive educational interventions such as Controlling Asthma in American Cities Project (CAACP), the Racial and Ethnic Approach to Community Health in the US Program and Healthy Hoops programs (REACH) have been described.

CONCLUSIONS

We believe that culturally sensitive community-based asthma education programs can serve as models for programs targeted toward Puerto Ricans to help decrease asthma morbidity. Moreover, greater sensitivity to Puerto Rican mores and folk remedies on the part of healthcare providers may improve the patient-clinician rapport and, hence, asthma outcomes. Finally, given ethnically based differences in pharmacogenomics, clinical trials targeting the Puerto Rican population may help to better define optimal asthma medication regimens in this ethnic group.

Factors associated with degree of atopy in Latino children in a nationwide pediatric sample: the Genes-environments and Admixture in Latino Asthmatics (GALA II) study

BACKGROUND

Atopy varies by ethnicity, even within Latino groups. This variation might be due to environmental, sociocultural, or genetic factors.

OBJECTIVE

We sought to examine risk factors for atopy within a nationwide study of US Latino children with and without asthma.

METHODS

Aeroallergen skin test responses were analyzed in 1830 US Latino subjects. Key determinants of atopy included country/region of origin, generation in the United States, acculturation, genetic ancestry, and site to which subjects migrated. Serial multivariate zero-inflated negative binomial regressions stratified by asthma status examined the association of each key determinant variable with the number of positive skin test responses. In addition, the independent effect of each key variable was determined by including all key variables in the final models.

RESULTS

In baseline analyses African ancestry was associated with 3 times (95% CI, 1.62-5.57) as many positive skin test responses in asthmatic participants and 3.26 times (95% CI, 1.02-10.39) as many positive skin test responses in control participants. Generation and recruitment site were also associated with atopy in crude models. In final models adjusted for key variables, asthmatic patients of Puerto Rican (exp[β] [95% CI], 1.31 [1.02-1.69]) and mixed (exp[β] [95% CI], 1.27 [1.03-1.56]) ethnicity had a greater probability of positive skin test responses compared with Mexican asthmatic patients. Ancestry associations were abrogated by recruitment site but not region of origin.

CONCLUSIONS

Puerto Rican ethnicity and mixed origin were associated with degree of atopy within US Latino children with asthma. African ancestry was not associated with degree of atopy after adjusting for recruitment site. Local environment variation, represented by site, was associated with degree of sensitization.

Sociocultural characteristics, obesity and inflammatory biomarkers in Puerto Rican toddlers born in New York City

BACKGROUND

In the USA, Puerto Rican children have a higher prevalence of asthma than other Latino ethnicities, and acculturation is one of hypothesized reasons for this difference. We examined associations between sociocultural characteristics and serum leptin, high-sensitivity C-reactive protein (hsCRP), and body mass index (BMI), and further, among hsCRP, leptin levels, BMI percentiles, and allergic sensitization in 2-year-old children.

METHODS

IgE antibodies, leptin, and hsCRP concentrations were measured in serum from Puerto Rican toddlers (n = 143) born in New York City with a maternal history of allergy and/or asthma. Demographic and home characteristics questionnaires were administered to the mother, postpartum and two years later. Children's weight and height were measured to determine BMI percentiles.

RESULTS

More girls (60%) had leptin levels above the median compared with boys (37%) (p = 0.0063). Leptin was positively correlated with BMI (r = 0.25; p = 0.0042). Children in daycare were more likely to be obese (40% vs. 24% p < 0.06). Maternal birthplace was significantly associated with children's leptin but not with hsCRP. Leptin levels were lower for children whose mothers were born on the US mainland (GM = 2.5 ng/ml, 95% CI [2.2-2.7]) compared with those whose mothers were born in Puerto Rico or another country (GM = 3.2 ng/ml, 95% CI [2.2-3.9], t-test p = 0.01). Mothers born in another country were more likely than those born in the US mainland or Puerto Rico to have obese children (60% vs. 26% p < 0.02). Leptin, hsCRP, and BMI percentile were not associated with sensitization to any of the measured inhalant allergens or total IgE.

CONCLUSION

Even at a very young age, some acculturation factors were associated with biomarkers and anthropometric measures of obesity among this Puerto Rican pediatric population. To our knowledge, this is the first study demonstrating the association of mother's birth place with child BMI and leptin as early as 24 months.

Integrative systems biology approaches in asthma pharmacogenomics

In order to improve therapeutic outcomes, there is a tremendous need to identify patients who are likely to respond to a given asthma treatment. Pharmacogenomic studies have explained a portion of the variability in drug response and provided an increasing list of candidate genes and SNPs. However, as phenotypic variation arises from a network of complex interactions among genetic and environmental factors, rather than individual genes or SNPs, a multidisciplinary, systems-level approach is required in order to understand the inter-relationships among these factors. Systems biology, which seeks to capture interactions between genetic factors and other variables, offers a promising approach to improved therapeutic outcomes in asthma. This aritcle will review and update progress in the pharmacogenomics of asthma and then discuss the application of systems biology approaches to asthma pharmacogenomics.

Age-related differences in asthma outcomes in the United States, 1988-2006

BACKGROUND

Relatively little is known about the effect of age on asthma outcomes in adults, particularly at a national level.

OBJECTIVE

To investigate age-related differences in asthma outcomes in a nationally representative, longitudinal study.

METHODS

We analyzed data from the Third National Health and Nutrition Examination Survey (1988-1994) with linked mortality files through 2006. Adults with physician-diagnosed asthma were identified and were divided into 2 age groups: younger adults (17-54 years of age) and older adults (55 years or older). The outcome measures were both cross-sectional (health care use, comorbidity, and lung function) and longitudinal (all-cause mortality).

RESULTS

There were an estimated 9,566,000 adults with current asthma. Of these, 73% were younger adults and 27% older adults. Compared with younger adults, older adults had more hospitalizations in the past year, more comorbidities, and poorer lung function (eg, lower forced expiratory volume in 1 second) (P < .05 for all). During a median follow-up of 15 years, significant baseline predictors of higher all-cause mortality included older age (≥55 vs <55 years old: adjusted hazard ratio [HR], 6.77; 95% confidence interval [CI], 3.15-14.54), poor health status (fair and poor vs excellent health status: adjusted HR, 10.07; 95% CI, 3.75-27.01), and vitamin D deficiency (vitamin D level <30 vs ≥50 nmol/L: adjusted HR, 2.19; 95% CI, 1.05-4.58), whereas Mexican American ethnicity (adjusted HR, 0.31; 95% CI, 0.14-0.65) was associated with lower mortality. Controlling for age, asthma was not associated with increased all-cause mortality (adjusted HR, 1.28; 95% CI, 0.99-1.65).

CONCLUSION

Older adults with asthma have a substantial burden of morbidity and increased mortality. The ethnic differences in asthma mortality and the vitamin D-mortality link merit further investigation.

Asthma Research for All of the United States

Asthma disproportionally affects different ethnic/racial groups, with Puerto Ricans and African Americans suffering the highest asthma prevalence and morbidity, Mexicans the lowest, and non-Hispanic whites in between. Genome-wide association studies of asthma have found both shared and race/ethnic-specific genetic risks factors for asthma. However, the majority of genetic asthma research is performed in populations of European descent, which limits the benefits of genetic research to European populations. It is important to biomedical and clinical research to include more diverse and underrepresented populations. The rich genetic diversity of all populations can be leveraged to scientific advantage. For example, admixture mapping provides a more powerful approach than traditional genome-wide allelic association studies in discovering genetic associations for complex diseases. By being more inclusive we can achieve a better understanding of the genetics of asthma, address health disparities, and ensure that scientific advances will benefit populations worldwide.

Effect of secondhand smoke on asthma control among black and Latino children

BACKGROUND

Among patients with asthma, the clinical effect and relative contribution of maternal smoking during pregnancy (in utero smoking) and current secondhand smoke (SHS) exposure on asthma control is poorly documented, and there is a paucity of research involving minority populations.

OBJECTIVES

We sought to examine the association between poor asthma control and in utero smoking and current SHS exposure among Latino and black children with asthma.

METHODS

We performed a case-only analysis of 2 multicenter case-control studies conducted from 2008-2010 with similar protocols. We recruited 2481 Latino and black subjects with asthma (ages 8-17 years) from the mainland United States and Puerto Rico. Ordinal logistic regression was used to estimate the effect of in utero smoking and current SHS exposures on National Heart, Lung, and Blood Institute-defined asthma control.

RESULTS

Poor asthma control among children 8 to 17 years of age was independently associated with in utero smoking (odds ratio [OR], 1.5; 95% CI, 1.1-2.0). In utero smoking through the mother was also associated with secondary asthma outcomes, including early-onset asthma (OR, 1.7; 95% CI, 1.1-2.4), daytime symptoms (OR, 1.6; 95% CI, 1.1-2.1), and asthma-related limitation of activities (OR, 1.6; 95% CI, 1.2-2.2).

CONCLUSIONS

Maternal smoking while in utero is associated with poor asthma control in black and Latino subjects assessed at 8-17 years of age.

Identification of ATPAF1 as a novel candidate gene for asthma in children

BACKGROUND

Asthma is a common disease of children with a complex genetic origin. Understanding the genetic basis of asthma susceptibility will allow disease prediction and risk stratification.

OBJECTIVE

We sought to identify asthma susceptibility genes in children.

METHODS

A nested case-control genetic association study of children of Caucasian European ancestry from a birth cohort was conducted. Single nucleotide polymorphisms (SNPs, n = 116,024) were genotyped in pools of DNA samples from cohort children with physician-diagnosed asthma (n = 112) and normal controls (n = 165). A genomic region containing the ATPAF1 gene was found to be significantly associated with asthma. Additional SNPs within this region were genotyped in individual samples from the same children and in 8 independent study populations of Caucasian, African American, Hispanic, or other ancestries. SNPs were also genotyped or imputed in 2 consortia control populations. ATPAF1 expression was measured in bronchial biopsies from asthmatic patients and controls.

RESULTS

Asthma was found to be associated with a cluster of SNPs and SNP haplotypes containing the ATPAF1 gene, with 2 SNPs achieving significance at a genome-wide level (P = 2.26 × 10(-5) to 2.2 × 10(-8)). Asthma severity was also found to be associated with SNPs and SNP haplotypes in the primary population. SNP and/or gene-level associations were confirmed in the 4 non-Hispanic populations. Haplotype associations were also confirmed in the non-Hispanic populations (P = .045-.0009). ATPAF1 total RNA expression was significantly (P < .01) higher in bronchial biopsies from asthmatic patients than from controls.

CONCLUSION

Genetic variation in the ATPAF1 gene predisposes children of different ancestries to asthma.

Ethnic variability in persistent asthma after in utero tobacco exposure

BACKGROUND

The effects of in utero tobacco smoke exposure on childhood respiratory health have been investigated, and outcomes have been inconsistent.

OBJECTIVE

To determine if in utero tobacco smoke exposure is associated with childhood persistent asthma in Mexican, Puerto Rican, and black children.

PATIENTS AND METHODS

There were 295 Mexican, Puerto Rican, and black asthmatic children, aged 8 to 16 years, who underwent spirometry, and clinical data were collected from the parents during a standardized interview. The effect of in utero tobacco smoke exposure on the development of persistent asthma and related clinical outcomes was evaluated by logistic regression.

RESULTS

Children with persistent asthma had a higher odds of exposure to in utero tobacco smoke, but not current tobacco smoke, than did children with intermittent asthma (odds ratio [OR]: 3.57; P = .029). Tobacco smoke exposure from parents in the first 2 years of life did not alter this association. Furthermore, there were higher odds of in utero tobacco smoke exposure in children experiencing nocturnal symptoms (OR: 2.77; P = .048), daily asthma symptoms (OR: 2.73; P = .046), and emergency department visits (OR: 3.85; P = .015) within the year.

CONCLUSIONS

Exposure to tobacco smoke in utero was significantly associated with persistent asthma among Mexican, Puerto Rican, and black children compared with those with intermittent asthma. These results suggest that smoking cessation during pregnancy may lead to a decrease in the incidence of persistent asthma in these populations.