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Respiratory IlnessNCT00342758

Early Life Factors and Respiratory Health in Mexico City Children

An observational study of Respiratory Ilness, run by National Institute of Environmental Health Sciences (NIEHS) at 4 sites in 2 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

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. Read more about this study

Who is it for?
Any age
Conditions the study is for
Respiratory Ilness
How many people
6,800 participants
Where
4 sitesin 2 countries
Study dates
1 Oct 2001to 15 Oct 2007
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages Any age
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Who may be able to join

  • 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 .

Who cannot join

None listed.

Trial locations and contacts

4 sites in 2 countries.

4 sites in 2 countries

Mexico3 sites
  • Hospital Infantil de Mexico Federico Gomez

    Mexico City

  • Instituto Mexicano del Seguro Social

    Mexico City

  • National Institute of Public Health

    Mexico City

Other trials in Mexico

United States1 site
  • NIEHS, Research Triangle Park

    Research Triangle Park, North Carolina, 27709

Other trials in United States

About this study

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.

Read more

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.

Read the 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.

Keywords
Asthma, Wheeze, Environment, Diet, Infection
Medical subject headings
Asthma, Respiratory Sounds, Infections

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted21 Jun 2006 (estimated)
  2. Study start1 Oct 2001
  3. Study completion15 Oct 2007

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Enrolment
6,800 participants
IDs, dates and publications
ClinicalTrials.gov ID
NCT00342758
Sponsor's protocol ID
999902005
Other IDs
02-E-N005
Status last verified
15 Oct 2007
First submitted
19 Jun 2006
Last updated
2 Jul 2017
Results posted
No

Questions about this trial

What is this clinical trial studying?

An observational study of Respiratory Ilness, run by National Institute of Environmental Health Sciences (NIEHS) at 4 sites in 2 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 0 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 2 Jul 2017. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 4 sites in Mexico, United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jul 2017.

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