Effects of Iron and/or Zinc Supplementation in Mexican School Children Exposed to Lead

Not Applicable

Completed

• Conditions: Lead Poisoning

• Registration Number: NCT02346188
• Lead Sponsor: Johns Hopkins Bloomberg School of Public Health

Brief Summary

Lead is negatively linked to nutritional status, behavior and cognition in children. Despite extensive knowledge of its toxicity and efforts to reduce exposure, lead continues to be a problem in developed and developing countries. When lead exposure is unavoidable due to its pervasive nature, effective means of protecting or disrupting that exposure need to be developed. Nutritional interventions are one such option. We conducted a 2x2 factorial, placebo-controlled trial of 6-month iron and zinc supplementation among lead-exposed children in Torreón, Mexico (altitude 1060 m). Nine schools were selected based on proximity to a lead smelter and first-graders were individually randomized to daily treatment with 30 mg iron, 30 mg zinc, both, or placebo. In addition to biochemical indicators, cognitive functions and behavior were evaluated at baseline, after the 6-month supplementation period, and again after another 6 months (without supplementation).

At baseline, 602 children ages 6.2-8.5 years were enrolled.

Detailed Description

We conducted a 2x2 factorial, placebo-controlled trial of 6-month iron and zinc supplementation among lead-exposed children in Torreón, Mexico (altitude 1060 m) to test the hypothesis that supplementation with iron, zinc or both will reduce blood lead concentrations of the children and improve their cognition and behavior. Nine schools were selected based on proximity to a lead smelter and first-graders were individually randomized to daily treatment with 30 mg iron, 30 mg zinc, both, or placebo. In addition to biochemical indicators (blood lead, serum ferritin, CRP, serum zinc, urinary arsenic concentrations), cognitive functions and behavior were measured. Assessments were conducted at three time points: at baseline, after the 6 month treatment, and again after another 6 months without treatment. At baseline, 602 children ages 6.2-8.5 years were enrolled.

Study Timeline

• Study Start: 2000-01
• Primary Completion: 2001-12
• Study Completion: 2001-12
• Status Verified: 2015-01
• Study First Submitted: 2015-01-20
• Study First Submitted QC: 2015-01-23
• Last Update Submitted: 2015-01-23
• Study First Posted: 2015-01-26
• Last Update Posted: 2015-01-26

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 602

Inclusion Criteria

• 1st grade child

Exclusion Criteria

• Blood lead concentration =>45 ug/dL
• Hemoglobin concentration < 9 g/dL

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: FACTORIAL

Primary Outcome Measures

Name	Time	Method
Blood lead concentration	6-12 months

Secondary Outcome Measures

Name	Time	Method
Anthropometric composite	6-12 months	Height, weight
Serum ferritin concentration	6-12 months
Serum zinc concentration	6-12 months
Hemoglobin concentration	6-12 months
Peabody Picture Vocabulary Test, Math achievement test, tests of attention and memory	6-12 months
Conners Behavior Rating Scales for parents and teachers	6-12 months

Trial Locations

Locations (1)

Johns Hopkins Bloomberg School of Public Health; 🇺🇸 Baltimore, Maryland, United States