Respiratory Ilness Clinical Trial
Official title:
Early Life Factors and Respiratory Health in Mexico City Children
| Verified date | October 15, 2007 |
| Source | National Institutes of Health Clinical Center (CC) |
| Contact | n/a |
| Is FDA regulated | No |
| Health authority | |
| Study type | Observational |
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.
| Status | Completed |
| Enrollment | 6800 |
| Est. completion date | October 15, 2007 |
| Est. primary completion date | |
| Accepts healthy volunteers | No |
| Gender | All |
| Age group | N/A and older |
| Eligibility |
- 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 . |
| Country | Name | City | State |
|---|---|---|---|
| Mexico | Hospital Infantil de Mexico Federico Gomez | Mexico City | |
| Mexico | Instituto Mexicano del Seguro Social | Mexico City | |
| Mexico | National Institute of Public Health | Mexico City | |
| United States | NIEHS, Research Triangle Park | Research Triangle Park | North Carolina |
| Lead Sponsor | Collaborator |
|---|---|
| National Institute of Environmental Health Sciences (NIEHS) |
United States, Mexico,