Renal Oxygen Consumption, Insulin Sensitivity, and Daily Caloric Restriction in ADPKD (EXPLORE)

April 27, 2026 updated by: University of Colorado, Denver

Renal Oxygen Consumption, Insulin Sensitivity, and Daily Caloric Restriction in Autosomal Dominant Polycystic Kidney Disease (EXPLORE Study)

The proposed research is a pilot study assessing kidney oxidative metabolism and insulin sensitivity after a 2-year weight loss intervention in those with autosomal dominant polycystic kidney disease who are overweight or obese.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

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.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Autosomal dominant polycystic kidney disease (ADPKD) is the most commonly inherited progressive kidney disease. Overweight and obese phenotypes have been associated with disease progression in early-stage ADPKD. Daily caloric restriction (DCR, 34% restriction per day from baseline weight maintenance requirements) may aid in weight loss and ultimately slow ADPKD disease progression. Weight loss via DCR may cause alterations in kidney oxidative metabolism and insulin sensitivity that can affect ADPKD disease progression. This study aims to assess kidney oxidative metabolism via 11C-acetate PET scan protocol and insulin sensitivity via hyperinsulinemic-euglycemic clamp by leveraging an ongoing R01-funded trial (NCT04907799) in DCR (n=10) vs. control (n=10) groups at baseline (BSL) and 2 years. The study will utilize the clinical outcome measures performed in the parent trial to address the subsequent novel aims: Aim 1: Compare kidney oxidative metabolism and insulin sensitivity at BSL and 2 years in adults with ADPKD. Aim 2: Define the relations among changes in kidney oxidative metabolism, insulin sensitivity, total kidney volume, and weight over 2 years. Currently, it is unknown if weight loss via DCR modifies renal energy expenditure and substrate utilization.

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.
Interventional

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

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

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

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Colorado
      • Aurora, Colorado, United States, 80045
        • University of Colorado- Anschutz Medical Campus

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • 18-65 years of age
  • ADPKD diagnosis based on the modified Pei-Ravine criteria
  • Body-mass index of 25-45 kg/m^2
  • Estimated glomerular filtration rate ≥ 30 mL/min/1.73m^2
  • Total kidney volume (htTKV) > 600 mL, calculated from a previous kidney ultrasound or magnetic resonance imaging performed within the last 12 months
  • Access to the internet with video chat capabilities
  • No plans for extended travel (>2 weeks) without internet access during the 12-month intensive period
  • Not currently participating in or planning to participate in any formal weight loss or physical activity program, or another interventional study
  • Ability to provide informed consent

Exclusion Criteria:

  • Diabetes mellitus
  • Current smokers or history of smoking in the past 12 months
  • Alcohol dependence or abuse
  • History of hospitalization or major surgery within the last 3 months
  • Untreated dyslipidemia
  • Uncontrolled hypertension
  • Pregnancy, lactation, or unwillingness to use adequate birth control
  • Cardiovascular disease, peripheral vascular disease, or symptoms suggestive of cardiovascular disease: chest pain, shortness of breath at rest or with mild exertion, syncope
  • Abnormal resting electrocardiogram (ECG): serious arrhythmias, including multifocal premature ventricular contractions (PVC's), frequent PVC's (defined as 10 or more per min), ventricular tachycardia (defined as runs of 3 or more successive PVC's), or sustained atrial tachyarrhythmia; 2nd or 3rd degree A-V block, QTc interval > 480 msec or other significant conduction defects
  • Significant pulmonary disease including: chronic obstructive pulmonary disease, interstitial lung disease, cystic fibrosis, or uncontrolled asthma
  • Regular use of prescription or over-the-counter medications that may affect weight, appetite, food intake, or energy metabolism
  • History of clinically diagnosed eating disorder including: anorexia nervosa, bulimia, binge eating disorder
  • Weight loss of >5% in the past 3 months for any reason except post-partum weight loss; weight gain >5% requires assessment by PI
  • Major psychiatric disorder (e.g., psychosis, schizophrenia, mania, bipolar disorder) or current severe depression, based on DSM-IV-TR criteria for Major Depressive Episode, which in the opinion of the Study MD would interfere with ability to adhere to dietary interventions)
  • Inability to cooperate with or clinical contraindication for magnetic resonance imaging, including: severe claustrophobia, implants, devices, or non-removable body piercings
  • Previous obesity treatment with surgery or weight loss device, except: (1) liposuction and/or abdominoplasty if performed > 1 year before screening, (2) lap banding if the band has been removed > 1 year before screening, (3) intragastric balloon if the balloon has been removed > 1 year before screening (4) duodenal-jejunal bypass sleeve, if the sleeve has been removed > 1 year before screening or 5) AspireAssist or other endoscopically placed weight loss device if the device has been removed > 1 year before screening.

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: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Daily Caloric Restriction
The daily caloric restriction group will participate in a 2-year, group-based, behavioral weight loss intervention based on a 30% reduction in caloric intake and increased physical activity.
Behavioral: Daily caloric restriction
Weight loss based on daily caloric restriction and increased physical activity
Other: Other: Standard Advice Control
The standard advice control group will receive an initial consultation with a registered dietician regarding current clinical recommendations for ADPKD without subsequent counseling sessions.
Other: Standard advice control
Initial nutrition consultation without subsequent counseling

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
Measure Description
Time Frame
Change in renal oxygen consumption
Time Frame: Baseline, 24-months
Renal oxygen consumption will be assessed by a PET/CT scan using 11-C acetate
Baseline, 24-months
Change in insulin sensitivity
Time Frame: Baseline, 24-months
Insulin sensitivity will be assessed by a hyperinsulinemic-euglycemic clamp
Baseline, 24-months

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.
University of Colorado, Denver

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Nutrition Obesity Research 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

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.
January 13, 2023

Primary Completion (Estimated)

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.
August 1, 2027

Study Completion (Estimated)

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.
August 1, 2027

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).
July 3, 2024

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.
July 3, 2024

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.
July 11, 2024

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 1, 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

Keywords

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.
  • 22-0979
  • P30DK048520 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

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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