Vitamin A Supplementation at Birth and Atopy in Childhood
The Effect of Vitamin A Supplementation at Birth on the Development of Atopy in Childhood: Long-term Follow-up of a Randomised Placebo-controlled Trial
INTRODUCTION Eight trials studying the effect of providing neonatal vitamin A supplementation (NVAS) have been reported, and another four are underway to test whether NVAS should become WHO policy. Three of the four African trials were conducted by the Bandim Health Project (BHP) in Guinea-Bissau. One of them was a two-by-two factorial trial among low-birth-weight children. From 2004-2008, the children were randomly allocated to 25,000 IU vitamin A or placebo at birth, and furthermore to BCG vaccination at birth or later as is local policy. In 2011, the investigators conducted a follow-up study. A remarkably strong harmful effect of NVAS on atopy and wheezing was found (manuscript under review).
Seen in the context that NVAS may soon become a WHO policy it is obviously worrying if NVAS is associated with a higher risk of atopy and wheezing. The investigators therefore aim to conduct a similar follow-up study of participants in the first NVAS trial conducted in Guinea-Bissau from 2002-2004, among normal-birth-weight infants, to test whether NVAS is associated with an increased risk of atopy and wheezing and other allergic symptoms as well as growth.
METHODS
Study population:
From 2002-2004 BHP conducted a randomised trial of NVAS. The investigators recruited newborns when they came for BCG vaccination. Provided parental consent, they received an oral supplement of 50,000 IU vitamin A or placebo.
Study design:
This study will be a follow-up study of the cohort of children randomised to NVAS (intervention) or placebo (current policy) together with BCG vaccine at birth.
Other exposures:
The investigators will also investigate the effect of receiving an additional dose of measles vaccine and the timing of DTP vaccine on the development of atopy.
Assessment of outcomes:
The investigators will visit all children at the last known address. Height, weight and mid upper arm circumference will be measured. BCG scar will be examined and vaccination card details recorded by the field assistant. Children will be excluded from skin prick testing (SPT) if they have a history suggestive of anaphylaxis or are currently using anti-histamine medication. SPT will be performed using aero-allergens, food allergens and positive histamine and negative saline control. The mother or guardian will be interviewed by a local assistant. Symptoms of eczema and asthma as well as food allergy will be assessed.
Statistical analysis:
Effect of randomisation group and other factors on outcomes will be analysed in multivariable regression models. All analyses will be adjusted for skin prick tester. All analyses will be conducted stratified by sex.
調査の概要
研究の種類
入学 (予想される)
連絡先と場所
研究場所
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-
Bissau Codex
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Bissau、Bissau Codex、ギニアビサウ、1004
- Bandim Health Project
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参加基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
サンプリング方法
調査対象母集団
説明
Inclusion Criteria:
- Enrolled at birth in NCT00168610
Exclusion Criteria:
- Children with history suggestive of anaphylaxis will be excluded from skin prick testing but included in the study population
研究計画
研究はどのように設計されていますか?
デザインの詳細
この研究は何を測定していますか?
主要な結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
---|---|---|
Atopic sensitisation
時間枠:Single observation on day of recruitment
|
Skin prick test positivity.
A wheal >=3mm will be considered positive.
|
Single observation on day of recruitment
|
二次結果の測定
結果測定 |
メジャーの説明 |
時間枠 |
---|---|---|
Symptoms of asthma
時間枠:Single observation on day of recruitment
|
Questionnaire based on ISAAC survey for 6-7 year olds
|
Single observation on day of recruitment
|
Symptoms of eczema
時間枠:Single observation on day of recruitment
|
Questionnaire based on ISAAC survey for 6-7 year olds
|
Single observation on day of recruitment
|
Symptoms of food allergy
時間枠:Single observation of day of recruitment
|
Questionnaire based on Health Nuts survey
|
Single observation of day of recruitment
|
その他の成果指標
結果測定 |
メジャーの説明 |
時間枠 |
---|---|---|
Weight
時間枠:Single observation on day of recruitment
|
Single observation on day of recruitment
|
|
Height
時間枠:Single observation on day of recruitment
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Single observation on day of recruitment
|
|
Mid-upper arm circumference
時間枠:Single observation on day of recruitment
|
Single observation on day of recruitment
|
|
Hospitalisations
時間枠:Single observation on day of recruitment
|
Single observation on day of recruitment
|
|
Infectious diseases
時間枠:Single observation on day of recruitment
|
History of chickenpox or measles
|
Single observation on day of recruitment
|
協力者と研究者
スポンサー
捜査官
- 主任研究者:Christine Benn, DMSc、Statens Serum Institut
出版物と役立つリンク
研究記録日
主要日程の研究
研究開始
一次修了 (実際)
研究の完了 (予想される)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (見積もり)
学習記録の更新
投稿された最後の更新 (見積もり)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
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