Zinc Supplements in Lowering Cadmium Levels in Smokers

Phase 2

Completed

• Conditions: Gastric Cancer; Lung Cancer; Kidney Cancer; Bladder Cancer; Cervical Cancer; Esophageal Cancer; Leukemia; Head and Neck Cancer; Liver Cancer; Pancreatic Cancer

• Registration Number: NCT00376987
• Lead Sponsor: Wake Forest University Health Sciences

Brief Summary

RATIONALE: Zinc supplements may lower cadmium levels in smokers and may help prevent DNA damage.

PURPOSE: This clinical trial is studying how well zinc supplements work in lowering cadmium levels in smokers.

Detailed Description

OBJECTIVES:

* Determine whether zinc supplements reduce cadmium levels in smokers.

* Measure serum levels of cotinine (a biomarker of smoking), zinc (a marker of compliance), and cadmium (the dependent variable) at 3 pre-supplementation visits and at 6 supplementation visits.

* Determine whether serum cadmium levels (adjusted for serum levels of cotinine) decrease during supplementation with VisiVite Smoker's Formula.

* Determine if increased cadmium levels in the blood of cigarette smokers can be correlated with decreased mismatch repair.

* Determine if administration of zinc-containing supplements reverses cadmium-induced inhibition of mismatch repair.

OUTLINE: This is an open-label, nonrandomized study.

Patients receive oral zinc supplements once daily for 12 weeks in the absence of unacceptable toxicity.

Blood, serum, and urine are collected once weekly for 3 weeks before beginning treatment and in weeks 5, 6, 9, 12, 15, and 17 for biomarker/laboratory analysis. Samples are examined for cadmium, zinc, and cotinine levels by atomic absorption spectrophotometry, expression of mismatch repair proteins (MSH2, MSH6, MSH3, MLH1, and PMS2), levels of messenger RNA by reverse transcriptase-polymerase chain reaction, and microsatellite instability by gel electrophoresis.

After completion of study therapy, patients are followed for 5 weeks.

Study Timeline

• Study Start: 2003-12
• Study First Submitted: 2006-09-13
• Study First Submitted QC: 2006-09-13
• Study First Posted: 2006-09-15
• Primary Completion: 2006-10
• Study Completion: 2015-06
• Status Verified: 2015-09
• Last Update Submitted: 2017-05-25
• Last Update Posted: 2017-05-30

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 61

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Reversal of cadmium-induced inhibition of mismatch repair	17 weeks
Correlation of increased cadmium levels with decreased mismatch repair	17 weeks
Serum levels of cotinine, zinc, and cadmium at 3 pre-supplementation visits and at 6 supplementation visits	17 weeks
Reduction of cadmium levels	17 weeks

Trial Locations

Locations (1)

Wake Forest University Comprehensive Cancer Center; 🇺🇸 Winston-Salem, North Carolina, United States