Glucose Homeostasis in Pseudohypoparathyroidism

April 27, 2026 updated by: Ashley Shoemaker, Vanderbilt University Medical Center

Glucose Homeostasis and Beta Cell Function in Pseudohypoparathyroidism

It is increasingly recognized that Pseudohypoparathyroidism type 1A (PHP1A) is associated with an increased risk of type 2 diabetes but the mechanism is unknown. In this pilot study we will assess β-cell function in patients with PHP1A and pseudopseudohypoparathyroidism PPHP.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Pseudohypoparathyroidism type 1A (PHP1A) is a rare, genetic disorder caused by impaired stimulatory G-protein signaling due to heterozygous mutations in the gene, GNAS. The most severe form of the disease, PHP1A occurs when a GNAS mutation is inherited on the preferentially expressed maternal allele. A less severe form of the disease, pseudopseudohypoparathyroidism (PPHP), occurs when a GNAS mutation is inherited on the paternal allele. Clinically, PHP1A is characterized by multi-hormone resistance, cognitive impairment and early-onset obesity while PPHP has a mild phenotype without multi-hormone resistance. It is increasingly recognized that PHP1A is associated with an increased risk of type 2 diabetes but the mechanism is unknown. Glucose homeostasis and diabetes risk has not been studied in PPHP. As part of the parent K23 award, we investigated glucose tolerance in children with PHP1A. In contrast to the adult literature, we found that children with PHP1A had greater insulin sensitivity than matched controls. When challenged with an oral glucose load, however, children with PHP1A had persistent hyperglycemia and 25% met criteria for impaired glucose tolerance. The goal of this proposal is to quantify β-cell function in PHP1A. It is plausible that these individuals have a) impaired β-cell function, b) differences in insulin sensitivity, and c) impaired incretin function. Thus, in this pilot study we will definitively assess one of these, β-cell function, using the frequently sampled intravenous glucose tolerance test in patients with PHP1A and PPHP (aim 1). We will also assess oral glucose tolerance over time by bringing back children and young adults with PHP1A from our original cohort for repeat glucose tolerance testing (aim 2). The ultimate goal is to rigorously define glucose homeostasis defects in PHP1A in order to design and conduct an intervention study for glucose intolerance and type 2 diabetes in PHP1A.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
14

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
    • Tennessee
      • Nashville, Tennessee, United States, 37212
        • Vanderbilt University Medical Center

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

6 years to 50 years (Child, Adult)

Accepts Healthy Volunteers

N/A

Sampling Method

Non-Probability Sample

Study Population

Patients with PHP1A/PPHP and matched controls

Description

Inclusion Criteria:

  1. Diagnosis of PHP1A/PPHP
  2. Age between 6 and 50 years old

Controls will be matched based on:

  1. Gender
  2. Race
  3. Age (±2 years if <25 years old or ±5 years if ≥25 years old)
  4. BMI (±2 kg/m2)
  5. Diabetes status

Exclusion Criteria:

  1. Treatment with appetite-altering drug or initiation of a new weight loss program in the past 3 months
  2. Type 1 diabetes
  3. Type 2 diabetes treated with insulin or GLP-1 receptor agonists or A1c >9%at their most recent clinic visit
  4. Pregnant or lactating women

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

  • Observational Models: Case-Control
  • Time Perspectives: Cross-Sectional

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Pseudphypoparathyroidism type 1A (PHP1A)
Case
Pseudopseudohypoparathyroidism (PPHP)
Case
Controls
Matched control group

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Insulin sensitivity (Si)
Time Frame: baseline
baseline

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Vanderbilt University Medical Center

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Ashley H Shoemaker, MD, Vanderbilt University Medical Center

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

Helpful Links

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 19, 2019

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 30, 2021

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 30, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 29, 2018

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 29, 2018

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
December 3, 2018

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 4, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Shoemaker R03

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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.

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