Latino populations: a unique opportunity for epidemiological research of asthma

Preference for and impact of telehealth vs in-person asthma visits among Black and Latinx adults

BACKGROUND

Black and Latinx adults experience disproportionate asthma-related morbidity and limited specialty care access. The severe acute respiratory syndrome coronavirus 2 pandemic expanded telehealth use.

OBJECTIVE

To evaluate visit type (telehealth [TH] vs in-person [IP]) preferences and the impact of visit type on asthma outcomes among Black and Latinx adults with moderate-to-severe asthma.

METHODS

For this PREPARE trial ancillary study, visit type preference was surveyed by e-mail or telephone post-trial. Emergency medical record data on visit types and asthma outcomes were available for a subset (March 2020 to April 2021). Characteristics associated with visit type preferences, and relationships between visit type and asthma outcomes (control [Asthma Control Test] and asthma-related quality of life [Asthma Symptom Utility Index]), were tested using multivariable regression.

RESULTS

A total of 866 participants consented to be surveyed, with 847 respondents. Among the participants with asthma care experience with both visit types, 42.0% preferred TH for regular checkups, which associated with employment (odds ratio [OR] = 1.61; 95% confidence interval [CI], 1.09-2.39; P = .02), lower asthma medication adherence (OR = 1.06; 95% CI, 1.01-1.11; P = .03), and having more historical emergency department and urgent care asthma visits (OR = 1.10 for each additional visit; 95% CI, 1.02-1.18; P = .02), after adjustment. Emergency medical record data were available for 98 participants (62 TH, 36 IP). Those with TH visits were more likely Latinx, from the Southwest, employed, using inhaled corticosteroid-only controller therapy, with lower body mass index, and lower self-reported asthma medication adherence vs those with IP visits only. Both groups had comparable Asthma Control Test (18.4 vs 18.9, P = .52) and Asthma Symptom Utility Index (0.79 vs 0.84, P = .16) scores after adjustment.

CONCLUSION

TH may be similarly efficacious as and often preferred over IP among Black and Latinx adults with moderate-to-severe asthma, especially for regular checkups.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02995733.

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.

An investigation of toxicities and survival in Hispanic children and adolescents with ALL: Results from the Dana-Farber Cancer Institute ALL Consortium protocol 05-001

PURPOSE

This study compared the relative incidence of treatment-related toxicities and the event-free and overall survival between Hispanic and non-Hispanic children undergoing therapy for acute lymphoblastic leukemia (ALL) on Dana-Farber Cancer Institute ALL Consortium protocol 05-001.

PATIENTS AND METHODS

Secondary analysis of prospectively collected data from a phase III multicenter study in children and adolescents of 1-18 years with previously untreated ALL.

RESULTS

Between 2005 and 2011, 794 eligible patients enrolled on DFCI 05-001, 730 of whom were included in this analysis (19% [N = 150] Hispanic, 73% [N = 580] non-Hispanic). Hispanic patients were more likely to be ≥10 years of age (32% vs. 24%, P = 0.045) at diagnosis. Toxicity analyses revealed that Hispanic patients had significantly lower cumulative incidence of bone fracture (P < 0.001) and osteonecrosis (ON; P = 0.047). In multivariable risk regression, the risk of ON was significantly lower in Hispanic patients ≥10 years (HR 0.23; P = 0.006). Hispanic patients had significantly lower 5-year event-free survival (EFS) (79.4%; 95% CI: 71.6-85.2) and overall survival (OS) (89.2%; 95% CI: 82.7-93.4) than non-Hispanic patients (EFS: 87.5%; 95% CI: 84.5-90.0, P = 0.004; OS: 92.7%; 95% CI: 90.2-94.6, P = 0.006). Exploratory analyses revealed differences between Hispanic and non-Hispanic patients in the frequency of common variants in genes related to toxicity or ALL outcome.

CONCLUSION

Hispanic children treated for ALL on DFCI 05-001 had fewer bone-related toxicities and inferior survival than non-Hispanic patients. While disease biology is one explanatory variable for outcome disparities, these findings suggest that biologic and non-biologic mechanisms affecting drug delivery and exposure in this population may be important contributing factors as well.

Evaluation of the Environmental Scoring System in Multiple Child Asthma Intervention Programs in Boston, Massachusetts

OBJECTIVES

To test the applicability of the Environmental Scoring System, a quick and simple approach for quantitatively measuring environmental triggers collected during home visits, and to evaluate its contribution to improving asthma outcomes among various child asthma programs.

METHODS

We pooled and analyzed data from multiple child asthma programs in the Greater Boston Area, Massachusetts, collected in 2011 to 2016, to examine the association of environmental scores (ES) with measures of asthma outcomes and compare the results across programs.

RESULTS

Our analysis showed that demographics were important contributors to variability in asthma outcomes and total ES, and largely explained the differences among programs at baseline. Among all programs in general, we found that asthma outcomes were significantly improved and total ES significantly reduced over visits, with the total Asthma Control Test score negatively associated with total ES.

CONCLUSIONS

Our study demonstrated that the Environmental Scoring System is a useful tool for measuring home asthma triggers and can be applied regardless of program and survey designs, and that demographics of the target population may influence the improvement in asthma outcomes.

Health Disparities in Patients with Pulmonary Arterial Hypertension: A Blueprint for Action. An Official American Thoracic Society Statement

BACKGROUND

Health disparities have a major impact in the quality of life and clinical care received by minorities in the United States. Pulmonary arterial hypertension (PAH) is a rare cardiopulmonary disorder that affects children and adults and that, if untreated, results in premature death. The impact of health disparities in the diagnosis, treatment, and clinical outcome of patients with PAH has not been systematically investigated.

OBJECTIVES

The specific goals of this research statement were to conduct a critical review of the literature concerning health disparities in PAH, identify major research gaps and prioritize direction for future research.

METHODS

Literature searches from multiple reference databases were performed using medical subject headings and text words for pulmonary hypertension and health disparities. Members of the committee discussed the evidence and provided recommendations for future research.

RESULTS

Few studies were found discussing the impact of health disparities in PAH. Using recent research statements focused on health disparities, the group identified six major study topics that would help address the contribution of health disparities to PAH. Representative studies in each topic were discussed and specific recommendations were made by the group concerning the most urgent questions to address in future research studies.

CONCLUSIONS

At present, there are few studies that address health disparities in PAH. Given the potential adverse impact of health disparities, we recommend that research efforts be undertaken to address the topics discussed in the document. Awareness of health disparities will likely improve advocacy efforts, public health policy and the quality of care of vulnerable populations with PAH.

The effects of prenatal "psychological" stressor exposure on lung inflammation and hyperresponsiveness in adult rat offspring

The aim of this study was to establish whether exposure of pregnant rats to uncontrollable (psychological) stressors might change the likelihood of their offspring to exhibit functional and histopathological abnormalities suggestive of asthma in adulthood. Pregnant rats (n = 16) underwent one of three treatments: electric shocks of a maximum duration of 10 s that could be escaped (controllable group; C) those that could not be escaped (uncontrollable group; U) or no shocks (control group; N). The offspring (n = 54) were kept in animal house under standard conditions until 3 months of age, when lung hyperresponsiveness, histopathology, immunohistochemical measurements of the cytokines interleukin (IL) 2, IL-4, IL-5, and IL-13 and actin as well as oxidative stress based on iNOS-positive cell counts and isoprostane PGF2α contents were assessed. The results showed that prenatal exposure to physical stressors (shocks) caused lung hyperresponsiveness and increased cytokine expression; exposure to uncontrollable shock (group U) had a differential effect on the expression of IL-2, IL-5, and IL-13 in inflammatory cells compared to exposure to controllable shock (group C), which characterizes the "psychological" aspect of stress. The results show that not only stress but also its uncontrollability during gestation might increase the likelihood that the offspring will exhibit functional and histopathological abnormalities suggestive of asthma. These findings strengthen the importance of psychological control with regard to environmental stimuli for the occurrence of several illnesses, suggesting the desirability of integration among various fields of science.

Complex genetics of pulmonary diseases: lessons from genome-wide association studies and next-generation sequencing

The advent of high-throughput technologies has provided exceptional assistance for lung scientists to discover novel genetic variants underlying the development and progression of complex lung diseases. However, the discovered variants thus far do not explain much of the estimated heritability of complex lung diseases. Here, we review the literature of successfully used genome-wide association studies (GWASs) and identified the polymorphisms that reproducibly underpin the susceptibility to various noncancerous complex lung diseases or affect therapeutic responses. We also discuss the inherent limitations of GWAS approaches and how the use of next-generation sequencing technologies has furthered our understanding about the genetic determinants of these diseases. Next, we describe the contribution of the metagenomics to understand the interactions of the airways microbiome with lung diseases. We then highlight the urgent need for new integrative genomics-phenomics methods to more effectively interrogate and understand multiple downstream "omics" (eg, chromatin modification patterns). Finally, we address the scarcity of genetic studies addressing under-represented populations such as African Americans and Hispanics.

Genome-wide association study and admixture mapping identify different asthma-associated loci in Latinos: the Genes-environments & Admixture in Latino Americans study

BACKGROUND

Asthma is a complex disease with both genetic and environmental causes. Genome-wide association studies of asthma have mostly involved European populations, and replication of positive associations has been inconsistent.

OBJECTIVE

We sought to identify asthma-associated genes in a large Latino population with genome-wide association analysis and admixture mapping.

METHODS

Latino children with asthma (n = 1893) and healthy control subjects (n = 1881) were recruited from 5 sites in the United States: Puerto Rico, New York, Chicago, Houston, and the San Francisco Bay Area. Subjects were genotyped on an Affymetrix World Array IV chip. We performed genome-wide association and admixture mapping to identify asthma-associated loci.

RESULTS

We identified a significant association between ancestry and asthma at 6p21 (lowest P value: rs2523924, P < 5 × 10(-6)). This association replicates in a meta-analysis of the EVE Asthma Consortium (P = .01). Fine mapping of the region in this study and the EVE Asthma Consortium suggests an association between PSORS1C1 and asthma. We confirmed the strong allelic association between SNPs in the 17q21 region and asthma in Latinos (IKZF3, lowest P value: rs90792, odds ratio, 0.67; 95% CI, 0.61-0.75; P = 6 × 10(-13)) and replicated associations in several genes that had previously been associated with asthma in genome-wide association studies.

CONCLUSIONS

Admixture mapping and genome-wide association are complementary techniques that provide evidence for multiple asthma-associated loci in Latinos. Admixture mapping identifies a novel locus on 6p21 that replicates in a meta-analysis of several Latino populations, whereas genome-wide association confirms the previously identified locus on 17q21.

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.

Access to and use of asthma health services among Latino children: the Rhode Island-Puerto Rico asthma center study

This study determines asthma-related health care access and utilization patterns for Latino children of Puerto Rican and Dominican origin residing in Rhode Island (RI) and Latino children residing in Puerto Rico (Island). Data included 804 families of children with persistent asthma recruited from clinics. Island children were less likely to receive regular asthma care and care from a consistent provider and more likely to have been to the emergency department and hospitalized for asthma than RI children. Island children were 2.33 times more likely to have used the emergency department for asthma compared with RI non-Latino White (NLW) children. Latino children residing in both Island and RI were less likely to have used specialty care and more likely to have had a physician visit for asthma in the past year than RI NLW children. The differences might reflect the effects of the different delivery systems on pediatric health care utilization and asthma management.

Evidence of how rs7575840 influences apolipoprotein B-containing lipid particles

OBJECTIVE

Recent genome-wide association studies identified a variant rs7575840 in the apolipoprotein B (APOB) gene region as associated with low-density lipoprotein (LDL) cholesterol. However, the underlying functional mechanism of this variant, which resides 6.5 kb upstream of APOB, has remained unknown. Our objective was to investigate rs7575840 for association with refined apoB-containing lipid particles, for replication in a Mexican population, and for its underlying functional mechanism.

METHODS AND RESULTS

Our data show that rs7575840 is associated with serum apoB levels (P=4.85×10(-10)) and apoB-containing lipid particles, very small very-low-density lipoprotein, intermediate lipoprotein, and LDL particles (P=2×10(-5) to 9×10(-7)) in the Finnish Metabolic Syndrome in Men study sample (n=7710). Fine mapping of the APOB region using 43 single-nucleotide polymorphisms replicated the association of rs7575840 with apoB in a Mexican study sample (n=2666, P=3.33×10(-5)). Furthermore, our transcript analyses of adipose RNA samples from 175 subjects in the Finnish Metabolic Syndrome in Men study indicate that rs7575840 alters expression of APOB (P=1.13×10(-10)) and a regional noncoding RNA (BU630349) (P=7.86×10(-6)) in adipose tissue.

CONCLUSIONS

It has been difficult to convert genome-wide association study associations into mechanistic insights. Our data show that rs7575840 is associated with serum apoB levels and apoB-containing lipid particles, as well as influencing expression of APOB and a regional transcript BU630349 in adipose tissue. We thus provide evidence how a common genome-wide significant single-nucleotide polymorphism, rs7575840, may affect serum apoB, LDL cholesterol, and total cholesterol levels.

Ethnic differences in the effect of asthma on pulmonary function in children

RATIONALE

The impact of asthma on chronic lung function deficits is well known. However, there has been little study of ethnic differences in these asthma-associated deficits.

OBJECTIVES

To examine whether there are ethnic differences in the effects of asthma on children's lung function.

METHODS

We evaluated the impact of asthma on lung function in 3,245 Hispanic and non-Hispanic white school children (age 10-18 yr) in a longitudinal analysis of the Southern California Children's Health Study. Sex-specific mixed-effects regression spline models were fitted separately for each ethnic group.

MEASUREMENTS AND MAIN RESULTS

Large deficits in flows were observed among children with asthma diagnosed before age 4 years regardless of ethnicity. Hispanic girls with asthma had greater deficits in flows than non-Hispanic girls and were largest for maximal midexpiratory flow (-5.13% compared with -0.58%, respectively). A bigger impact of asthma in Hispanic girls was also found for FEV(1), FEF(75), and PEF (P value 0.04, 0.07, and 0.005, respectively). These ethnic differences were limited to girls diagnosed after age 4 years. In boys, asthma was also associated with greater deficits in flows among Hispanic than in non-Hispanic white children (differences that were not statistically significant). Ethnic differences in prevalence of pets and pests in the home, health insurance coverage, parental education, and smoking did not explain the pattern of lung function differences.

CONCLUSIONS

Larger asthma-associated lung function deficits in Hispanics, especially among girls, merit further investigation to determine public health implications and to identify causes amenable to intervention.

Investigation of variants identified in caucasian genome-wide association studies for plasma high-density lipoprotein cholesterol and triglycerides levels in Mexican dyslipidemic study samples

BACKGROUND

Although epidemiological studies have demonstrated an increased predisposition to low high-density lipoprotein cholesterol and high triglyceride levels in the Mexican population, Mexicans have not been included in any of the previously reported genome-wide association studies for lipids.

METHODS AND RESULTS

We investigated 6 single-nucleotide polymorphisms associated with triglycerides, 7 with high-density lipoprotein cholesterol, and 1 with both triglycerides and high-density lipoprotein cholesterol in recent Caucasian genome-wide association studies in Mexican familial combined hyperlipidemia families and hypertriglyceridemia case-control study samples. These variants were within or near the genes ABCA1, ANGPTL3, APOA5, APOB, CETP, GALNT2, GCKR, LCAT, LIPC, LPL (2), MMAB-MVK, TRIB1, and XKR6-AMAC1L2. We performed a combined analysis of the family-based and case-control studies (n=2298) using the Z method to combine statistics. Ten of the single-nucleotide polymorphisms were nominally significant and 5 were significant after Bonferroni correction (P=2.20 x 10(-3) to 2.6 x 10(-11)) for the number of tests performed (APOA5, CETP, GCKR, and GALNT2). Interestingly, our strongest signal was obtained for triglycerides with the minor allele of rs964184 (P=2.6 x 10(-11)) in the APOA1/C3/A4/A5 gene cluster region that is significantly more common in Mexicans (27%) than in whites (12%).

CONCLUSIONS

It is important to confirm whether known loci have a consistent effect across ethnic groups. We show replication of 5 Caucasian genome-wide association studies lipid associations in Mexicans. The remaining loci will require a comprehensive investigation to exclude or verify their significance in Mexicans. We also demonstrate that rs964184 has a large effect (odds ratio, 1.74) and is more frequent in the Mexican population, and thus it may contribute to the high predisposition to dyslipidemias in Mexicans.

Variability in childhood allergy and asthma across ethnicity, language, and residency duration in El Paso, Texas: a cross-sectional study

BACKGROUND

We evaluated the impact of migration to the USA-Mexico border city of El Paso, Texas (USA), parental language preference, and Hispanic ethnicity on childhood asthma to differentiate between its social and environmental determinants.

METHODS

Allergy and asthma prevalence was surveyed among 9797 fourth and fifth grade children enrolled in the El Paso Independent School District. Parents completed a respiratory health questionnaire, in either English or Spanish, and a sub-sample of children received spirometry testing at their school. Here we report asthma and allergy outcomes across ethnicity and El Paso residency duration.

RESULTS

Asthma and allergy prevalence increased with longer duration of El Paso residency independent of ethnicity and preferred language. Compared with immigrants who arrived in El Paso after entering first grade (18%), lifelong El Paso residents (68%) had more prevalent allergy (OR, 1.72; 95% CI, 1.32 - 2.24), prevalent asthma (OR, 1.75; 95% CI, 1.24 - 2.46), and current asthma (OR, 2.01; 95% CI, 1.37 - 2.95). Spirometric measurements (FEV1/FVC and FEF25-75) also declined with increasing duration of El Paso residency (0.16% and 0.35% annual reduction, respectively).

CONCLUSION

These findings suggest that a community-wide environmental exposure in El Paso, delayed pulmonary development, or increased health of immigrants may be associated with allergy and asthma development in children raised there.

Asthma, allergy, and IgE levels in NYC head start children

BACKGROUND

Among preschool-age children in New York City neighborhoods with high asthma hospitalization rates, we analyzed the associations of total immunoglobulin E (IgE), specific IgE to common indoor allergens, and allergy symptoms with asthma.

METHODS

Parents of children in New York City Head Start programs were asked to complete a questionnaire covering demographic factors, health history (including respiratory conditions), lifestyle, and home environment. Children's serum samples were analyzed for total IgE and specific IgE antibodies to cockroach, dust mite, mouse, and cat allergens by immunoassay. Logistic regression was used to model the association between asthma and IgE, controlling for age, gender, ethnicity/national origin, BMI, parental asthma, smokers in the household, and allergy symptoms (e.g., runny nose, rash).

RESULTS

Among 453 participating children (mean age 4.0+/-0.5 years), 150 (33%) met our criteria for asthma. In our multivariable logistic regression models, children with asthma were more likely than other children to be sensitized to each allergen, to be sensitized to any of the four allergens (OR=1.6, 95% CI 1.0-2.6), or to be in the highest quartile of total IgE (OR=3.1, 95% CI 1.5-6.4). Allergy symptoms based on questionnaire responses were independently associated with asthma (OR=3.7, 95% CI 2.3-5.9).

CONCLUSIONS

Among preschool-aged urban children, asthma was associated with total IgE and sensitization to cat, mouse, cockroach, and dust mite allergens. However, allergy symptoms were more prevalent and more strongly associated with asthma than was any allergen-specific IgE; such symptoms may precede elevated specific IgE or represent a different pathway to asthma.

Asthma in Latin America: a public heath challenge and research opportunity

Asthma has emerged as an important public health problem in many Latin American countries over the past decade. In Brazil and Costa Rica, the prevalence of asthma and associated morbidity is as great or greater as reported in traditional high prevalence countries such as the US, but remains neglected as a public health priority. Asthma in Latin America is associated particularly with underprivileged populations living in cities but remains relatively rare in many rural populations. The causes of asthma in Latin America are likely to be associated with urbanization, migration, and the adoption of a modern 'Westernized' lifestyle and environmental changes that follow these processes that include changes in diet, physical activity, hygiene, and exposures to allergens, irritants, and outdoor and indoor pollutants. Because of the enormous social, genetic, and environmental contrasts within and between Latin American countries, and the large differences in prevalence associated with these differences, the investigation of asthma in Latin America provides important research opportunities to identify the social and biological mechanisms that underlie asthma development. Asthma in Latin America poses enormous challenges for health policy makers, health services, and researchers to respond to and alleviate the growing burden of asthma disability, particularly among marginalized urban populations.