Characterization of Hyperparathyroidism and Vitamin D Deficiency in Obesity

Obesity Clinical Trial

Official title:

Characterization of Hyperparathyroidism and Vitamin D Deficiency in Obesity

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00288873
• Other study ID #: 0509008122
• Status: Completed
• Phase: Phase 4
• Start date: February 2006
• Est. completion date: July 2007

Study information

• Verified date: December 2018
• Source: Weill Medical College of Cornell University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 60
• Est. completion date: July 2007
• Est. primary completion date: July 2007
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• Obese subjects with body mass indices greater than 40 kg/m2 or 35 kg/m2 with other medical conditions secondary to obesity

• Willingness to take vitamin D supplements

• If baseline vitamin D level is >25 ng/ml subjects will be eligible for the control group

• If baseline vitamin D level is <25 ng/ml subjects will be eligible for one of the two vitamin D replacement groups

Exclusion Criteria:

• Hypercalcemia

• Kidney disease

• Liver disease

• Malabsorption

• Prior diagnosis of bone disease

• Medical conditions requiring daily use of calcium, antacids, or medications known to affect bone metabolism or interact with vitamin D

• Hypersensitivity to any formulation of vitamin D

Related Conditions & MeSH terms

• Hyperparathyroidism
• Hyperparathyroidism, Secondary
• Obesity
• Secondary Hyperparathyroidism
• Vitamin D Deficiency

Intervention

Drug:
• Ergocalciferol

• Cholecalciferol

Locations

Country	Name	City	State
United States	Weill Cornell Medical College	New York	New York

Sponsors (1)

Lead Sponsor	Collaborator
Weill Medical College of Cornell University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Vitamin D (25OHD):RIA and HPLC
Primary	Parathyroid hormone (PTH):iPTH and 3rd generation RIA
Secondary	Parathyroid hormone carboxy terminal fragment levels PTH(7-84)
Secondary	Ratio of PTH (1-84) to PTH (7-84)
Secondary	Serum calcium level
Secondary	Urine calcium level