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

This study has been completed.
Children's Hospital of Philadelphia
University of California, San Francisco
Information provided by (Responsible Party):
Children's Hospital & Research Center Oakland Identifier:
First received: April 11, 2007
Last updated: October 4, 2011
Last verified: October 2011

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

Condition Intervention Phase
Dietary Supplement: Zinc
Dietary Supplement: Placebo
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
Official Title: Zinc and Bone Metabolism in Thalassemia

Resource links provided by NLM:

Further study details as provided by Children's Hospital & Research Center Oakland:

Primary Outcome Measures:
  • Change in Lumbar Spine Bone Mineral Density (BMD) by DXA (Baseline to 18 Months) [ Time Frame: 0 to 18 months ] [ Designated as safety issue: No ]
    Change in pa spine bone mineral density by DXA between baseline and 18 months

  • Change in Whole Body Bone Mineral Content (BMC) by DXA (Baseline to 18 Months) [ Time Frame: Baseline to 18 months ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Osteocalcin, a Marker of Bone Formation [ Time Frame: Baseline to 18 months ] [ Designated as safety issue: No ]
    Absolute change in serum osteocalcin between 0 and 18 months, intention to treat analysis between the zinc and placebo groups

Enrollment: 45
Study Start Date: April 2006
Study Completion Date: February 2011
Primary Completion Date: October 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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

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


Ages Eligible for Study:   6 Years to 30 Years
Genders Eligible for Study:   Both
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
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: 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
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

No publications provided by Children's Hospital & Research Center Oakland

Additional publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Children's Hospital & Research Center Oakland Identifier: NCT00459732     History of Changes
Obsolete Identifiers: NCT00480415
Other Study ID Numbers: 2004-106, K23HL076468
Study First Received: April 11, 2007
Results First Received: November 4, 2010
Last Updated: October 4, 2011
Health Authority: United States: Federal Government

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

Additional relevant MeSH terms:
Anemia, Hemolytic
Anemia, Hemolytic, Congenital
Genetic Diseases, Inborn
Hematologic Diseases
Zinc Sulfate
Dermatologic Agents
Growth Substances
Pharmacologic Actions
Physiological Effects of Drugs
Therapeutic Uses
Trace Elements processed this record on November 24, 2014