Characterization of Hyperparathyroidism and Vitamin D Deficiency in Obesity
Recruitment status was Active, not recruiting
Obese persons are known to have elevated levels of parathyroid hormone (PTH) and low levels of vitamin D. These hormones are important in regulation of the body’s calcium stores and bone health. We would like to investigate these abnormalities and the accuracy of our current diagnostic tests by comparing results of standard assays for vitamin D and PTH to more specific tests, in obese subjects at baseline and as vitamin D is replaced. We will also compare two standard vitamin D replacement regimens to determine if one is more effective.
This is a pilot study with two parts: Part 1 will compare levels of PTH and vitamin D using two different assays in obese subjects who have normal vitamin D and those who do not. We plan to enroll 20 subjects who have normal vitamin D levels and 40 subjects who have vitamin D insufficiency. All subjects will fill out questionnaires about the amount of calcium and vitamin D in their diet, and their recent sunlight exposure. We will ask for blood samples so that we can measure levels of calcium, vitamin D, albumin, creatinine, glucose, insulin and the different forms of PTH.
Subjects who have vitamin D insufficiency will then be randomized to receive Vitamin D2 or Vitamin D3 in standard doses for eight weeks, in an open label trial. At four and eight weeks, these subjects will fill out the above questionnaires and have the blood tests repeated. For safety purposes, urine calcium will also be monitored.
Vitamin D Deficiency
|Study Design:||Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Characterization of Hyperparathyroidism and Vitamin D Deficiency in Obesity|
- Vitamin D (25OHD):RIA and HPLC
- Parathyroid hormone (PTH):iPTH and 3rd generation RIA
- Parathyroid hormone carboxy terminal fragment levels PTH(7-84)
- Ratio of PTH (1-84) to PTH (7-84)
- Serum calcium level
- Urine calcium level
|Study Start Date:||February 2006|
|Estimated Study Completion Date:||July 2007|
|United States, New York|
|Weill Cornell Medical College|
|New York, New York, United States, 10021|
|Principal Investigator:||Emily M Stein, M.D.||Weill Medical College of Cornell University|