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Zinc & Bone Health in Thalassemia: The Think Zinc Study (ThinkZn)

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ClinicalTrials.gov Identifier: NCT00459732
Recruitment Status : Completed
First Posted : April 12, 2007
Results First Posted : September 30, 2011
Last Update Posted : October 7, 2011
Sponsor:
Collaborators:
National Heart, Lung, and Blood Institute (NHLBI)
Children's Hospital of Philadelphia
University of California, San Francisco
Information provided by (Responsible Party):
Children's Hospital & Research Center Oakland

Study Type Interventional
Study Design Allocation: Randomized;   Intervention Model: Parallel Assignment;   Masking: Double (Participant, Investigator);   Primary Purpose: Treatment
Condition Thalassemia
Interventions Dietary Supplement: Zinc
Dietary Supplement: Placebo
Enrollment 45
Recruitment Details Subjects were recruited from 3 hematology clinics in the US between April, 2006 and May, 2008. 114 potentially eligible patients were screened, 43 were considered eligible and consented to participation.
Pre-assignment Details Following enrollment, prior to group assignment, subjects were screened for copper and vitamin D status. If serum copper was <70ug/dL and/or 25OH vitamin D <20ng/mL, they were placed on daily supplementation, 2 mg Cu/day and/or 1000 IU vitamin D/day.
Arm/Group Title Zinc Placebo
Hide Arm/Group Description 25 mg of zinc as zn sulfate taken daily daily capsule similar in size/color to zn was taken daily by this group
Period Title: Overall Study
Started 23 17
Completed 19 [1] 14 [2]
Not Completed 4 3
[1]
4 on zn dropped: 1 pregnant and 1 nausea after baseline, 1 lost to followup, 1 exited after 12 month
[2]
3 on placebo dropped: 1 pregnant after 12 mo, 1 lost to followup, one died after 12 month timepoint
Arm/Group Title Zinc Placebo Total
Hide Arm/Group Description 25 mg of zinc as zn sulfate taken daily daily capsule similar in size/color to zn was taken daily by this group Total of all reporting groups
Overall Number of Baseline Participants 23 17 40
Hide Baseline Analysis Population Description
[Not Specified]
Age, Categorical  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 23 participants 17 participants 40 participants
<=18 years
10
  43.5%
9
  52.9%
19
  47.5%
Between 18 and 65 years
13
  56.5%
8
  47.1%
21
  52.5%
>=65 years
0
   0.0%
0
   0.0%
0
   0.0%
Age Continuous  
Mean (Standard Deviation)
Unit of measure:  Years
Number Analyzed 23 participants 17 participants 40 participants
17.7  (5.6) 17.4  (4.9) 17.6  (5.3)
Sex: Female, Male  
Measure Type: Count of Participants
Unit of measure:  Participants
Number Analyzed 23 participants 17 participants 40 participants
Female
12
  52.2%
9
  52.9%
21
  52.5%
Male
11
  47.8%
8
  47.1%
19
  47.5%
Region of Enrollment  
Measure Type: Number
Unit of measure:  Participants
United States Number Analyzed 23 participants 17 participants 40 participants
23 17 40
Plasma Zinc   [1] 
Mean (Standard Deviation)
Unit of measure:  mcg/dL
Number Analyzed 23 participants 17 participants 40 participants
77  (11) 79  (14) 78  (12)
[1]
Measure Description: Concentration of zinc within the plasma at baseline, mcg/dL
Spine Z-score   [1] 
Mean (Standard Deviation)
Unit of measure:  Z-score
Number Analyzed 23 participants 17 participants 40 participants
-1.9  (1.0) -2.4  (1.1) -2.1  (1.0)
[1]
Measure Description: Spine standard deviation score (Z-score) determined by baseline DXA bone density scan
1.Primary Outcome
Title Change in Lumbar Spine Bone Mineral Density (BMD) by DXA (Baseline to 18 Months)
Hide Description Change in pa spine bone mineral density by DXA between baseline and 18 months
Time Frame 0 to 18 months
Hide Outcome Measure Data
Hide Analysis Population Description
Intention to treat analysis of all subjects who completed the protocol in each arm of the study (zinc vs. placebo).
Arm/Group Title Zinc Placebo
Hide Arm/Group Description:
25 mg of zinc as zn sulfate taken daily
daily capsule similar in size/color to zn was taken daily by this group
Overall Number of Participants Analyzed 18 14
Mean (Standard Deviation)
Unit of Measure: Percent Change
5.9  (5.3) 1.5  (9.0)
Show Statistical Analysis 1 Hide Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Zinc, Placebo
Comments [Not Specified]
Type of Statistical Test Superiority or Other
Comments [Not Specified]
Statistical Test of Hypothesis P-Value 0.13
Comments [Not Specified]
Method ANOVA
Comments [Not Specified]
2.Primary Outcome
Title Change in Whole Body Bone Mineral Content (BMC) by DXA (Baseline to 18 Months)
Hide Description [Not Specified]
Time Frame Baseline to 18 months
Hide Outcome Measure Data
Hide Analysis Population Description
Intention to treat analysis in those who completed the 18 month timepoint (zinc vs. placebo)
Arm/Group Title Zinc Placebo
Hide Arm/Group Description:
25 mg of zinc as zn sulfate taken daily
daily capsule similar in size/color to zn was taken daily by this group
Overall Number of Participants Analyzed 17 14
Mean (Standard Deviation)
Unit of Measure: Percent change
6.1  (6.1) 2.2  (9.2)
Show Statistical Analysis 1 Hide Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Zinc, Placebo
Comments [Not Specified]
Type of Statistical Test Superiority or Other
Comments [Not Specified]
Statistical Test of Hypothesis P-Value 0.44
Comments [Not Specified]
Method ANOVA
Comments Repeated measures
3.Secondary Outcome
Title Osteocalcin, a Marker of Bone Formation
Hide Description Absolute change in serum osteocalcin between 0 and 18 months, intention to treat analysis between the zinc and placebo groups
Time Frame Baseline to 18 months
Hide Outcome Measure Data
Hide Analysis Population Description
Intention to treat analysis
Arm/Group Title Zinc Placebo
Hide Arm/Group Description:
25 mg of zinc as zn sulfate taken daily
daily capsule similar in size/color to zn was taken daily by this group
Overall Number of Participants Analyzed 19 14
Mean (Standard Deviation)
Unit of Measure: ng/mL
8.8  (17.1) -4.3  (23.2)
Show Statistical Analysis 1 Hide Statistical Analysis 1
Statistical Analysis Overview Comparison Group Selection Zinc, Placebo
Comments [Not Specified]
Type of Statistical Test Superiority or Other
Comments [Not Specified]
Statistical Test of Hypothesis P-Value 0.16
Comments [Not Specified]
Method ANCOVA
Comments Repeated measures analysis of variance adjusted for baseline osteocalcin level.
Time Frame Recorded between baseline and 18 month time point (end of study)
Adverse Event Reporting Description Adverse events were collected at 5 timepoints, 3, 6, 12 and 18 months after start of supplementation.
 
Arm/Group Title Zinc Placebo
Hide Arm/Group Description 25 mg of zinc as zn sulfate taken daily daily capsule similar in size/color to zn was taken daily by this group
All-Cause Mortality
Zinc Placebo
Affected / at Risk (%) Affected / at Risk (%)
Total   --/--      --/--    
Show Serious Adverse Events Hide Serious Adverse Events
Zinc Placebo
Affected / at Risk (%) # Events Affected / at Risk (%) # Events
Total   0/23 (0.00%)      1/17 (5.88%)    
Cardiac disorders     
Death  [1]  0/23 (0.00%)  0 1/17 (5.88%)  1
Indicates events were collected by systematic assessment
[1]
One subject on the placebo arm of the trial died from cardiomyopathy secondary to iron overload after the 12 month time point.
Show Other (Not Including Serious) Adverse Events Hide Other (Not Including Serious) Adverse Events
Frequency Threshold for Reporting Other Adverse Events 5%
Zinc Placebo
Affected / at Risk (%) # Events Affected / at Risk (%) # Events
Total   17/19 (89.47%)      8/14 (57.14%)    
Blood and lymphatic system disorders     
Fatigue  [1]  5/19 (26.32%)  6 5/14 (35.71%)  6
Gastrointestinal disorders     
Nausea   10/19 (52.63%)  14 8/14 (57.14%)  10
Diarrhea   3/19 (15.79%)  7 5/14 (35.71%)  7
Stomach Upset  [2]  11/19 (57.89%)  13 8/14 (57.14%)  11
Nervous system disorders     
Headache   8/19 (42.11%)  9 8/14 (57.14%)  9
Indicates events were collected by systematic assessment
[1]
Fatigue that is different that usual pre-transfusion fatigue
[2]
Includes general stomach upset and/or cramping
Certain Agreements
Principal Investigators are NOT employed by the organization sponsoring the study.
There is NOT an agreement between Principal Investigators and the Sponsor (or its agents) that restricts the PI's rights to discuss or publish trial results after the trial is completed.
Results Point of Contact
Name/Title: Ellen Fung, PhD RD CCD
Organization: Children's Hospital & Research Center, Oakland
Phone: 510-428-3885 ext 4939
Responsible Party: Children's Hospital & Research Center Oakland
ClinicalTrials.gov Identifier: NCT00459732     History of Changes
Obsolete Identifiers: NCT00480415
Other Study ID Numbers: 2004-106
K23HL076468 ( U.S. NIH Grant/Contract )
First Submitted: April 11, 2007
First Posted: April 12, 2007
Results First Submitted: November 4, 2010
Results First Posted: September 30, 2011
Last Update Posted: October 7, 2011