Effect of urbanisation on asthma, allergy and airways inflammation in a developing country setting
- Colin L Robinson1,2,
- Lauren M Baumann1,2,
- Karina Romero2,
- Juan M Combe2,
- Alfonso Gomez2,
- Robert H Gilman2,3,4,
- Lilia Cabrera2,
- Guillermo Gonzalvez4,
- Nadia N Hansel1,5,6,
- Robert A Wise1,
- Kathleen C Barnes1,5,
- Patrick N Breysse6,
- William Checkley1,2,3,4
- 1Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
- 2AB PRISMA, Lima, Perú
- 3Department of International Health, Program in Global Disease Epidemiology and Control, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- 4CRONICAS Center of Excellence for Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru
- 5Division of Allergy and Clinical Immunology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
- 6Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Correspondence to William Checkley, Division of Pulmonary and Critical Care, Johns Hopkins University, 1830 Monument Street, Fifth Floor, Baltimore, MD 21205, USA;
Contributors All authors were involved in the study design and writing of the manuscript. CLR directly contributed to the study design, supervision of field activities in both Tumbes and Lima, and is responsible for data management and analysis, and writing of this manuscript. LMB contributed equally to the study design, administration of field work, and data management and analysis, and also contributed to the writing of the manuscript. RHG is the main investigator at the Lima site and provided technical support during the conduct of the study. KR, JMC and AG were the on-site study physicians who performed most physical testing and were extensively involved in administering field work. LC is the field work supervisor at the Lima site, and provided census data and technical support. GG is the physician supervisor for research activities at the Tumbes site, and provided census data and technical support. NNH and RAW contributed to the study design and provided technical support for the study. KCB contributed to the study design and provided logistical support for the study. PNB contributed to study design of the environmental measurements, and provided both technical support and equipment for our study. WC had ultimate oversight over the study design and administration, and was equally responsible for the analysis and writing of the manuscript.
- Received 5 January 2011
- Accepted 2 June 2011
- Published Online First 5 July 2011
Background Asthma is a growing public health problem in developing countries. However, few studies have studied the role of urbanisation in this phenomenon. It was hypothesised that children living in a peri-urban setting in Peru have higher rates of asthma and allergy than rural counterparts.
Methods 1441 adolescents aged 13–15 years were enrolled from two settings: a peri-urban shanty town in Lima (n=725) and 23 rural villages in Tumbes (n=716). Participants filled in questionnaires on asthma and allergy symptoms, environmental exposures and sociodemographics, and underwent spirometry, and exhaled nitric oxide (eNO) and allergy skin testing. Indoor particulate matter (PM) concentrations were measured in 170 households.
Results Lima adolescents had higher rates of lifetime wheezing (22% vs 10%), current asthma symptoms (12% vs 3%) and physician-diagnosed asthma (13% vs 2%; all p <0.001). Current rhinitis (23% vs 12%), eczema (12% vs 0.4%), atopy (56% vs 38%), personal history of cigarette smoking (7.4% vs 1.3%) and mean indoor PM (31 vs 13 μg/m3) were also higher in Lima (all p <0.001). The peri-urban environment of Lima was associated with a 2.6-fold greater odds (95% CI 1.3 to 5.3) of asthma in multivariable regression. Forced expiratory volumes were higher and FEV1/FVC (forced expiratory volume in 1 s/forced vital capacity) ratios were lower in Lima (all p <0.001). Higher eNO values in Lima (p <0.001) were attributable to higher rates of asthma and atopy.
Conclusions Peri-urban adolescents had more asthma, atopy and airways inflammation and were exposed to more indoor pollution. The findings provide evidence of the risks posed to lung health by peri-urban environments in developing countries.
- Asthma risk
- exhaled nitric oxide
- developing country
- asthma epidemiology
- clinical epidemiology
- exhaled airway markers
See Editorial, p 1025
Funding The study was supported by the Johns Hopkins Center for Global Health (Principal Investigator NNH) and the Fogarty International Center, National Institutes of Health (NIH; grant R24 TW007988). WC was supported by a Clinician Scientist Award from the Johns Hopkins University, a K99/R00 Pathway to Independence Award (K99HL096955) from the National Heart, Lung and Blood Institute, NIH and by a contract (HHSN268200900033C) with the National Heart, Lung and Blood Institute, NIH. KCB was supported in part by the Mary Beryl Patch Turnbull Scholar Program. CLR was a Fogarty International Clinical Research Scholar during the time of the study and was further supported by Tufts University School of Medicine and by a pre-doctoral T35 Training Grant (T35AI065385) of the NIH. LMB was supported by a predoctoral T35 Training Grant (T35AI065385) of the NIH. Support for exposure measurements was provided by National Institute for Environmental Health Sciences grant numbers (ES015803). RAW was supported in part by the Dorney–Koppel Family Foundation. NNH, WC and PNB were also supported by an R01 grant from the National Institutes of Environmental Health Sciences (R01ES018845). Study sponsors played no role in the study design, data collection, data analysis, data interpretation or the decision to submit the article for publication. The opinions, results and conclusions reported in this paper are those of the authors and are independent from the funding sources. All authors had full access to all of the data (including statistical reports and tables) in the study and can take responsibility for the integrity of the data and the accuracy of the data analysis.
Competing interests None.
Ethics approval This study was conducted with the approval of the Institutional Review Boards of the Johns Hopkins Bloomberg School of Public Health in Baltimore, USA, and AB PRISMA in Lima, Peru.
Provenance and peer review Not commissioned; externally peer reviewed.