Clinical Trial on Respiratory Ilness - Clinical Trials Registry

Study Overview

Status

Completed

Conditions

Respiratory Ilness

Detailed Description

Early life exposures now appear to be important in modulation of the immune response and tendency to develop asthma. We plan to enroll a cohort of children at birth to study early life factors in the development of wheezing and respiratory illness during the first six years of life in Mexico City. In particular, we will consider the role of early diet (particularly antioxidant intake, lactation and obesity), infections, dust mite and cockroach antigens, traffic related air pollution, and environmental tobacco smoke. We will also consider the potential modifying effect of genetic predisposition with respect to the exposures of interest.

Approximately 6,800 children will be enrolled at birth. The goal is to follow the cohort though age 6. To increase the number of expected cases of asthma, we will partially enrich the cohort for increased risk of asthma by virtue of having a parent with doctor diagnosis of asthma or allergies; the remaining cohort will not be enriched to preserve generalizability.

Pregnant women enrolled in a prepaid health plan in Mexico City (the Insituto Mexicano de Seguridad Social, henceforth referred to as IMSS) will be screened for the study and invited to enrolled their newborns when they come for delivery at one of two IMSS hospitals. An initial home visit during the first three months of life will include assessment of environmental exposures and infant diet. Children will be followed through age six with yearly home visits, monitoring of acute lower respiratory illness during the first year of life and periodic review of the IMSS medical records.

We have chosen Mexico City because of the relatively low rates of asthma in the face of prevalent exposures to factors that are thought to increase asthma risk in urban areas in the United States. These include dust mites, cockroach, airborne pollutants and social factors such as low income and young maternal age. This pattern suggests that protective factors may be operating in Mexico City that could shed light on the etiology of worldwide childhood asthma epidemic. Potential candidates include exposure to certain early infections that shift the developing immune system away from the pattern of allergic asthmatic response. We are also especially interested in potential protective effects of early nutrition. Exposure to ozone in this population is the highest in North American and thus antioxidant intake may be especially important. In order to evaluate these protective hypotheses, we will also collect information on risk factors believed to be related to increased risk of asthma in US cities such as allergens, traffic related air pollutants, and lower respiratory infection with respiratory syncytial virus.

Study Type

Observational

Enrollment

6800

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Mexico
- - Mexico City, Mexico
    - National Institute of Public Health
  - Mexico City, Mexico
    - Hospital Infantil de México Federico Gómez
  - Mexico City, Mexico
    - Instituto Mexicano del Seguro Social
United States
- North Carolina
  - Research Triangle Park, North Carolina, United States, 27709
    - NIEHS, Research Triangle Park

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Child
Adult
Older Adult

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

INCLUSION CRITERIA:

Patients must be pregnant coming to deliver.

Patients must have convenient access to a phone.

Patients must be residents of Mexico City, Mexico.

Women patients must not be planning to move from their current residence in the next two years or to drop their IMSS coverage .

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National Institute of Environmental Health Sciences (NIEHS)

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2001

Study Completion

October 15, 2007

Study Registration Dates

First Submitted

June 19, 2006

First Submitted That Met QC Criteria