Suspected Deficient Activation of Vitamin D in Patients With Secondary Hyperparathyroidism
Information source: University of Maryland
ClinicalTrials.gov processed this data on August 20, 2015
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Secondary Hyperparathyroidism
Intervention: Teriparatide (Drug)
Phase: N/A
Status: Completed
Sponsored by: University of Maryland Official(s) and/or principal investigator(s):
Elizabeth A Streeten, MD, Principal Investigator, Affiliation: Division of Endocrinology, University of Maryland School of Medicine
Summary
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.
Clinical Details
Official title: Clinical and Molecular Characterization of Suspected Partial 25-hydroxyvitamin D-1-alpha-hydroxylase Deficiency
Study design: Allocation: Non-Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Diagnostic
Primary outcome: The Level of Activated Vitamin D (1,25-dihydroxyvitamin D) After Parathyroid Hormone Infusion at Baseline, 4 and 8 Hours
Secondary outcome: The Number of Patients With Mutations in CYP27B1
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.
Eligibility
Minimum age: 40 Years.
Maximum age: 59 Years.
Gender(s): Female.
Criteria:
Inclusion Criteria:
- Caucasian female
- Age 40-59 years
- Serum creatinine < 1. 3 and estimated glomerular filtration rate (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 glomerular filtration rate (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
Locations and Contacts
University of Maryland School of Medicine Division of Endocrinology, Baltimore, Maryland 21201, United States
Additional Information
Starting date: February 2007
Last updated: May 13, 2014
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