E-DRUG: Role of zinc in prevention of childhood diarrhea
Rakesh Aggarwal, MD, DM a),b), John Sentz, MPH c) and Mark A. Miller, MD c)
Role of Zinc Administration in Prevention of Childhood Diarrhea and
Respiratory Illnesses: A Meta-analysis. PEDIATRICS 2007; 119(6): 1120-1130
(June 2007). (doi:10.1542/peds.2006-3481)
a: Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute
of Medical Sciences, Lucknow, India b: Department of Gastroenterology,
All India Institute of Medical Sciences, New Delhi, India c: Division of
International Epidemiology and Population Studies, Fogarty International
Center, National Institutes of Health, Bethesda, Maryland
BACKGROUND. The quantified effect of zinc supplementation to prevent
childhood diarrhea and respiratory illnesses is unclear. We conducted a
meta-analysis of randomized, controlled trials on the subject.
METHODS. We searched PubMed, Science Citation Index, and the Cochrane
Database of Controlled Trials and hand-searched the reference lists of
identified articles. All randomized, controlled trials of zinc
supplementation for 3 months for children <5 years of age, using blinded
assessment, were eligible. The outcome measures studied were number of
episodes of illness, number of days with illness, and number of episodes
of severe illness. Data from 17 studies were pooled by using
random-effects and fixed-effects models for data with and without
significant heterogeneity, respectively.
RESULTS. Children who received a zinc supplement had fewer episodes of
diarrhea (rate ratio: 0.86) and respiratory tract infections (rate
ratio: 0.92) and significantly fewer attacks of severe diarrhea or dysentery
(rate ratio: 0.85), persistent diarrhea (rate ratio: 0.75), and lower
respiratory tract infection or pneumonia (rate ratio: 0.80) than did
those who received placebo. They also had significantly fewer total days
with diarrhea (rate ratio: 0.86) but not days with respiratory illness (rate
ratio: 0.95). Published studies showed a publication bias and significant
heterogeneity; however, no cause for the latter could be identified.
CONCLUSIONS. Zinc supplementation reduced significantly the frequency
and severity of diarrhea and respiratory illnesses and the duration of
diarrheal morbidity. The relatively limited reduction in morbidity and
the presence of significant heterogeneity and of publication bias
indicate the need for larger, high-quality studies to identify
subpopulations most likely to benefit.
Key Words: diarrhea ? respiratory illness ? meta-analysis ? nutrition ?
supplementation ? zinc
Abbreviations: CI?confidence interval ? RR?rate ratio