Key Partners: Cronicas, Prisma, Universidad Peruana Cayetano Heredia, London School of Hygiene, and Tropical Medicine

Understanding the effects of rapid urbanization remains a challenge concerning chronic non-communicable diseases (NCDs). Peru offers a unique opportunity to assess the impact of geographical variation on NCDs. Comprehensive data generated by the CRONICAS Cohort Study across a diversity of scenarios has provided important advances towards understanding NCD burden and epidemiology in low- and middle-income countries.

The CRONICAS Cohort Study had two main aims. First, we evaluated the effects of variation in geographical settings on cardiovascular and chronic pulmonary diseases. Second, being aware of the reliance on biomass fuels, a feature that distinguishes low-resource settings from high-income countries, we are also looking into the longitudinal evaluation of lung function across different settings. Exposure to by-products of biomass fuel combustion is considered to be the most important risk factor for COPD after cigarette smoking.

This study was a joint effort between Johns Hopkins University and Universidad Peruana Cayetano Heredia. It was funded by the United States National Institutes of Health and has been implemented in three different sites with varying degrees of urbanization, outdoor and household air pollution exposures, and altitude above sea level.

Lima

Altitude: Sea level
Setting: Dense shantytown outside center of Lima
Vehicular Traffic: Dense throughout the day
Development: Paved and dirt roads
Indoor Pollution: Primarily influenced by outdoor air pollution

Urban Puno

Altitude: 3,825 m elevation
Setting: Dense city center    
Vehicular Traffic: Dense between 7am-7pm, otherwise minimal
Development: Primarily paved roads    
Indoor Pollution: Primarily influenced by outdoor air pollution

Rural Puno

Altitude: 3,825 m elevation
Setting: Farming communities far from city center
Vehicular Traffic: Little to none. Bicycles and walking are the primary forms of transportation
Development: All dirt roads    
Indoor Pollution: Indoor cookstoves

Tumbes

Altitude: Sea level
Setting: Semi-urban setting with enrollment predominantly from farming communities far from city center
Vehicular Traffic: Little to none. Bicycles and walking are the primary forms of transportation
Development: Primarily dirt roads    
Indoor Pollution: Outdoor or semi-indoor cookstoves

Miranda JJ, Bernabe-Ortiz A, Smeeth L, Gilman RH, Checkley W; CRONICAS Cohort Study Group. Addressing geographical variation in the progression of non-communicable diseases in Peru: the CRONICAS cohort study protocol. BMJ Open 2012 2(1):e000610.

Key Partners: Prisma and Universidad Peruana Cayetano Heredia

The GASP study, conducted between 2012 and 2014, was a case-control plus longitudinal follow-up study enrolling 666 children 9-19 years of age with current or previous asthma and 571 children without asthma living in the peri-urban communities of Pampas de San Juan de Miraflores and Villa El Salvador in Lima, Peru. At baseline, we conducted severity assessments (NAEPP-3 and Asthma Control Test), anthropometric measurements, and a comprehensive questionnaire including information on socioeconomic status, other demographic variables, asthma family history, and exposure history. In addition, all children received pre- and post-bronchidlator spirometry (lung function) testing, exhaled nitric oxide testing, and blood draws at baseline. Sera were analyzed for total and antigen-specific IgE concentrations, as well as micronutrient (vitamin D, folate, zinc) concentrations. Children with asthma were followed up for a 6-9 month period on a bimonthly basis, during which we measured healthcare utilization and asthma control (Asthma Control Test). We also performed pre- and post-bronchodilator spirometry on children with asthma quarterly during follow-up. Finally, allergen testing in the household and gravimetric and real-time pollutant (PM2.5, black carbon, NO2) concentrations were measured in a subset of households, and inverse distance weighting methods were used to estimate household exposures to pollutants for each participating household.

Results: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5457560/

Key Partners: Makerere University

Chronic respiratory diseases are a leading cause of death worldwide, and the majority of morbidity and mortality related to chronic respiratory disease occurs in low- and middle-income countries. Urbanization is increasing rapidly among these countries, and the fastest rate of urbanization is occurring in Sub-Saharan Africa. The LiNK study is a longitudinal cohort aimed at assessing the role of urbanization in lung function decline in Uganda. The primary aim of the study was to examine the differences in prevalence of CRDs and attributable risk factors in urban and rural Uganda. The initial enrollment occurred in 2015 and consisted of randomly selected population-based sample of 1,543 located in the urban capital of Uganda, Kampala, and a rural district, Nakaseke. All participants had anthropometric measurements taken and demographic questionnaires including biomass fuel smoke exposure, HIV status, and history of post-treatment pulmonary tuberculosis applied. Spirometry was conducted using the Easy-On-PC spirometer (ndd, Zurich, Switzerland) on all participants. The LiNK Study investigators aim to conduct follow up at 3 years and 5 years as part of longitudinal analysis of risk factors for lung function decline in this setting.

The LiNK Cohort Study represents a partnership between Johns Hopkins University and Makerere Lung Institute in Uganda. The study was funded through the Fogarty International Center and COPD Foundation.

Key Partners: Prisma and Universidad Peruana Cayetano Heredia

The PURA study, which took place from 2009-2010, was a population-based study of 1,441 adolescents ages 13-15 years living in two cities in Peru with differing levels of urbanization. 725 adolescents were recruited in Lima, the capital city of Peru, where over 1/3 of the population resides and is highly urbanized; 716 were from Tumbes, a less urbanized, coastal city near the border with Ecuador. We administered a questionnaire on asthma symptoms, environmental exposures, and socio-demographics, and all participants underwent pre- and post- bronchodilator spirometry, skin allergy testing, and exhaled nitric oxide testing. Finally, we obtained blood samples for hematocrit, total IgE levels, vitamin D levels and DNA in all participants and measured indoor particulate matter concentrations for 48 hours in a random subset of 70-100 households at each site.

Protocol: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3289983/