Zinc Supplements in Lowering Cadmium Levels in Smokers
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.
|Bladder Cancer Cervical Cancer Esophageal Cancer Gastric Cancer Head and Neck Cancer Kidney Cancer Leukemia Liver Cancer Lung Cancer Pancreatic Cancer Tobacco Use Disorder||Dietary Supplement: zinc oxide||Phase 2|
|Study Design:||Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: No masking
Primary Purpose: Prevention
|Official Title:||Do Dietary Supplements of Zinc Reduce Serum Cadmium Levels in Smokers?|
- Reduction of cadmium levels [ Time Frame: 17 weeks ]
- Serum levels of cotinine, zinc, and cadmium at 3 pre-supplementation visits and at 6 supplementation visits [ Time Frame: 17 weeks ]
- Correlation of increased cadmium levels with decreased mismatch repair [ Time Frame: 17 weeks ]
- Reversal of cadmium-induced inhibition of mismatch repair [ Time Frame: 17 weeks ]
|Study Start Date:||December 2003|
|Study Completion Date:||June 2015|
|Primary Completion Date:||October 2006 (Final data collection date for primary outcome measure)|
Dietary Supplement: zinc oxide
- 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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00376987
|United States, North Carolina|
|Wake Forest University Comprehensive Cancer Center|
|Winston-Salem, North Carolina, United States, 27157-1096|
|Principal Investigator:||Gary G. Schwartz, MD, PhD, MPH||Wake Forest University Health Sciences|