Zinc Supplements in Lowering Cadmium Levels in Smokers

May 25, 2017 updated by: Wake Forest University Health Sciences

Do Dietary Supplements of Zinc Reduce Serum 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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Dietary supplement: zinc oxide

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 Type

Interventional

Enrollment (Actual)

Phase

Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

United States
- North Carolina
  - Winston-Salem, North Carolina, United States, 27157-1096
    - Wake Forest University Comprehensive Cancer Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

21 years to 120 years (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Genders Eligible for Study

All

Description

DISEASE CHARACTERISTICS:

Currently smoking ≥ 1 pack (20 cigarettes) per day
Baseline cadmium level ≥ 0.5 μg/L

PATIENT CHARACTERISTICS:

Negative pregnancy test
Fertile patients must use effective contraception
No known gastrointestinal upset due to zinc vitamins or lozenges

PRIOR CONCURRENT THERAPY:

At least 2 weeks since prior and no other concurrent vitamins and zinc supplements

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Primary Purpose: PREVENTION
Allocation: NON_RANDOMIZED
Interventional Model: SINGLE_GROUP
Masking: NONE

What is the study measuring?

Primary Outcome Measures

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

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Wake Forest University Health Sciences

Collaborators

National Cancer Institute (NCI)

Investigators

Principal Investigator: Gary G. Schwartz, MD, PhD, MPH, Wake Forest University Health Sciences

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

December 1, 2003

Primary Completion (ACTUAL)

October 1, 2006

Study Completion (ACTUAL)

June 1, 2015

Study Registration Dates

First Submitted

September 13, 2006

First Submitted That Met QC Criteria