Characterization of Hyperparathyroidism and Vitamin D Deficiency in Obesity

December 18, 2018 updated by: Weill Medical College of Cornell University

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

60

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • New York
      • New York, New York, United States, 10021
        • Weill Cornell Medical College

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Vitamin D (25OHD):RIA and HPLC
Parathyroid hormone (PTH):iPTH and 3rd generation RIA

Secondary Outcome Measures

Outcome Measure
Parathyroid hormone carboxy terminal fragment levels PTH(7-84)
Ratio of PTH (1-84) to PTH (7-84)
Serum calcium level
Urine calcium level

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Weill Medical College of Cornell University

Investigators

  • Principal Investigator: Emily M Stein, M.D., Weill Medical College of Cornell University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2006

Primary Completion (Actual)

July 1, 2007

Study Completion (Actual)

July 1, 2007

Study Registration Dates

First Submitted

February 6, 2006

First Submitted That Met QC Criteria

February 6, 2006

First Posted (Estimate)

February 8, 2006

Study Record Updates

Last Update Posted (Actual)

December 20, 2018

Last Update Submitted That Met QC Criteria

December 18, 2018

Last Verified

December 1, 2018

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 0509008122

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe