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

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00459732
Recruitment Status : Completed
First Posted : April 12, 2007
Results First Posted : September 30, 2011
Last Update Posted : October 7, 2011
Information provided by (Responsible Party):

Study Description
Brief Summary:
The purpose of this study is to test whether zinc can improve bone health in young patients with thalassemia.

Condition or disease Intervention/treatment Phase
Thalassemia Dietary Supplement: Zinc Dietary Supplement: Placebo Phase 2

Detailed Description:
The primary aim of this study is to determine if zinc supplementation improves bone health in young patients with thalassemia. Osteoporosis is a significant co-morbidity in patients with thalassemia which leads to decreased quality of life. The most effective way to prevent osteoporosis is to build strong, dense bones in the early years. A combination of disease, endocrine and nutritional factors likely contribute to the etiology of osteoporosis in this population. However, even well transfused patients with normal gonadal function who are supplemented with calcium have low bone mass. It is hypothesized that patients with thalassemia have low bone mass, in part, due to zinc deficiency. Sub-optimal zinc status has been identified in patients with thalassemia and zinc supplementation has been shown to improve linear growth. To test the primary hypothesis, an 18 month randomized placebo-controlled trial of zinc supplementation (25 mg Zn/day) vs. placebo will be conducted in 60 young patients (6-30 yrs) with thalassemia and low bone mass (spine BMD Z-score <-1.0). Bone health, as estimated from measurements of bone mass (by DXA and pQCT) and markers of bone formation and resorption will be the primary outcome variables. This will be the first study to examine the effects of zinc supplementation on bone health in patients with thalassemia. If zinc supplementation is found to have a clinically important effect, this simple, safe, non-invasive therapy could quickly become a part of the standard care of these young patients and improve overall health in children and adult patients with thalassemia

Study Design

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 45 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Zinc and Bone Metabolism in Thalassemia
Study Start Date : April 2006
Primary Completion Date : October 2009
Study Completion Date : February 2011

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Thalassemia
U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Placebo Comparator: Placebo Capsule
placebo capsule, similar in size, shape and color to zinc capsule, taken once daily for 18 months
Dietary Supplement: Placebo
Placebo capsule, identical to the zn capsule in size, shape and color, taken once daily for 18 months
Other Name: "sugar" pill
Active Comparator: Zinc (25 mg/d)
25 mg of elemental Zinc as zinc sulphate taken once daily for 18 months
Dietary Supplement: Zinc
25 mg of elemental zinc as zinc sulphate take once daily for 18 months
Other Names:
  • zinc sulphate
  • elemental zinc

Outcome Measures

Primary Outcome Measures :
  1. Change in Lumbar Spine Bone Mineral Density (BMD) by DXA (Baseline to 18 Months) [ Time Frame: 0 to 18 months ]
    Change in pa spine bone mineral density by DXA between baseline and 18 months

  2. Change in Whole Body Bone Mineral Content (BMC) by DXA (Baseline to 18 Months) [ Time Frame: Baseline to 18 months ]

Secondary Outcome Measures :
  1. Osteocalcin, a Marker of Bone Formation [ Time Frame: Baseline to 18 months ]
    Absolute change in serum osteocalcin between 0 and 18 months, intention to treat analysis between the zinc and placebo groups

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   6 Years to 30 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • 6 to 30 years of age
  • thalassemia
  • bone mineral density Z-score < -1.0 (by DXA)

Exclusion Criteria:

  • Bone marrow transplant recipient
  • Currently prescribed treatment for low bone mass other than calcium or vitamin D (e.g. calcitonin, bisphosphonates)
  • Currently prescribed zinc supplementation who are unable or unwilling to stop during this trial
  • Currently participating in another trial with a medication known to affect bone mineral density.
  • Chronic use of systemic corticosteroids
  • Untreated hypogonadism or growth hormone deficiency
  • Baseline serum copper < 70 µg/dL
  • Baseline vitamin D-25OH < 11 ng/mL
  • Pregnant or lactating at study entry
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00459732

United States, California
Children's Hospital & Research Center, Oakland
Oakland, California, United States, 94609
University of California, San Francisco
San Francisco, California, United States, 94143
United States, Pennsylvania
Children's Hospital of Philadelphia
Philadelphia, Pennsylvania, United States, 19104
Sponsors and Collaborators
Children's Hospital & Research Center Oakland
National Heart, Lung, and Blood Institute (NHLBI)
Children's Hospital of Philadelphia
University of California, San Francisco
Principal Investigator: Ellen B. Fung, PhD, RD Children's Hospital & Research Center Oakland
More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
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 Posted: April 12, 2007    Key Record Dates
Results First Posted: September 30, 2011
Last Update Posted: October 7, 2011
Last Verified: October 2011

Keywords provided by Children's Hospital & Research Center Oakland:
zinc, thalassemia, bone mineral density

Additional relevant MeSH terms:
Anemia, Hemolytic, Congenital
Anemia, Hemolytic
Hematologic Diseases
Genetic Diseases, Inborn
Zinc Sulfate
Trace Elements
Growth Substances
Physiological Effects of Drugs
Dermatologic Agents