Suspected Deficient Activation of Vitamin D in Patients With Secondary Hyperparathyroidism (1hydroxylase)

The recruitment status of this study is unknown because the information has not been verified recently.
Verified October 2008 by University of Maryland.
Recruitment status was  Active, not recruiting
Information provided by:
University of Maryland Identifier:
First received: September 17, 2008
Last updated: October 7, 2008
Last verified: October 2008

The purpose of this study is to determine if a reduction in the enzyme 1-hydroxylase, which activates Vitamin D, is the cause of overactivity of the parathyroid glands (called secondary hyperparathyroidism - normal blood calcium and elevated parathyroid hormone) in a selected group of young patients with normal kidney function.

Condition Intervention
Secondary Hyperparathyroidism
Drug: Teriparatide

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Diagnostic
Official Title: Clinical and Molecular Characterization of Suspected Partial 25-Hydroxyvitamin D-1-Alpha-Hydroxylase Deficiency

Resource links provided by NLM:

Further study details as provided by University of Maryland:

Primary Outcome Measures:
  • The level of activated Vitamin D (1,25-dihydroxyvitamin D) after parathyroid hormone infusion [ Time Frame: 4 and 8 hours after start of infusion ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Abnormalities in the gene for the 1-hydroxylase enzyme [ Time Frame: baseline ] [ Designated as safety issue: No ]

Estimated Enrollment: 16
Study Start Date: February 2007
Estimated Study Completion Date: August 2008
Estimated Primary Completion Date: August 2008 (Final data collection date for primary outcome measure)
Intervention Details:
    Drug: Teriparatide
    Teriparatide will be given by continuous intravenous infusion at a rate of 12 pmol/kg/hr for 8 hours to both "patients" and "controls"
    Other Name: Forteo
Detailed Description:

Vitamin D, an essential nutrient, is produced by the skin after sunlight shines on it. Vitamin D must then be activated by both the liver and the kidneys to perform its function of maintaining strong bones and helping to prevent heart disease, infection, diabetes and cancer. Reduced kidney activation of Vitamin D occurs with advanced age and with all kidney diseases. We have identified a small group of patients who appear to have reduced ability of the kidneys to activate vitamin D, even though they are young and do not have chronic kidney disease. In these patients, we are comparing the ability of their kidneys to activate Vitamin D to that of healthy controls. To stimulate the kidneys to activate Vitamin D, we are giving parathyroid hormone intravenously over 8 hours and collecting blood and urine at baseline, 4 and 8 hours. This type of parathyroid infusion does not cause side effects. The gene that controls this activation is also being studied (by a simple blood test) to look for abnormalities. We are now actively recruiting healthy controls for this study.


Ages Eligible for Study:   40 Years to 59 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Caucasian female
  • Age 40-59 years
  • Serum creatinine < 1.3 and estimated GRF > 60
  • Serum calcium in the normal range (for U Md lab 8.6-10 mg/dl)
  • Parathyroid hormone in the normal range (for U Md lab 12-54 pg/ml)
  • Normal 25-hydroxyvitamin D level (30 ng/ml or higher)
  • For women of childbearing age, non-pregnant (based on negative urine pregnancy test on the morning of the teriparatide infusion)

Exclusion Criteria:

  • Non-caucasian
  • Age under 40 and over 59 years
  • Male
  • Serum creatinine over 1.3 or estimated GFR < 60
  • Abnormal serum calcium (for U Md lab, below 8.6 or above 10 mg/dl)
  • Abnormal parathyroid hormone (for U Md lab, above 65 or below 12 pg/ml)
  • For women of childbearing age, non-pregnant (based on urine pregnancy test on the morning of the teriparatide infusion)
  • History of bone radiation
  • History of Paget disease of bone
  • History of bone malignancy or metastases
  • History of allergy or sensitivity to Forteo
  Contacts and Locations
Please refer to this study by its identifier: NCT00754442

United States, Maryland
University of Maryland School of Medicine Division of Endocrinology
Baltimore, Maryland, United States, 21201
Sponsors and Collaborators
University of Maryland
Principal Investigator: Elizabeth A Streeten, MD Division of Endocrinology, University of Maryland School of Medicine
  More Information

No publications provided

Responsible Party: Elizabeth A. Streeten, MD, Division of Endocrinology, University of Maryland School of Medicine Identifier: NCT00754442     History of Changes
Other Study ID Numbers: H-28679, H-28679
Study First Received: September 17, 2008
Last Updated: October 7, 2008
Health Authority: United States: Food and Drug Administration

Keywords provided by University of Maryland:
vitamin D
vitamin D deficiency

Additional relevant MeSH terms:
Hyperparathyroidism, Secondary
Parathyroid Diseases
Endocrine System Diseases
Vitamin D
Bone Density Conservation Agents
Physiological Effects of Drugs
Pharmacologic Actions
Growth Substances processed this record on April 17, 2014