Influence of Glucose on Metabolism and Clinical Symptoms of Patients With Parkinson's Disease (PaGlu)

September 16, 2025 updated by: Eva Schaeffer, University Hospital Schleswig-Holstein
Many patients with Parkinson's Disease (PD) report an increased consumption of fast-acting sugars. This tendency to consume sweet, high-sugar foods occurs in some patients even before the onset of cardinal motor symptoms. Some recent studies have demonstrated that PD patients have an increased consumption of fast-acting carbohydrates compared to healthy controls. However, the reason for this change in eating behavior has not yet been adequately explained. It is discussed that the increased sugar intake leads to an increased dopamine release in the brain via an increase in insulin and thus to an improvement in clinical symptoms. This study investigates the influence of fast-acting carbohydrates on insulin and glucose blood levels as well as motor and non-motor symptoms in patients with PD using an oral glucose tolerance test and a placebo oral glucose tolerance test in a crossover design.

Study Overview

Status

Status

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

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 (Estimated)

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.
50

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

  • Germany
      • Kiel, Germany, 24118
        • Recruiting
        • Department for Neurology, University of Kiel
        • Contact:

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

Sampling Method

Probability Sample

Study Population

The study population includes Parkinson's Disease patients with and without sweet cravings. Recruitment of patients takes place in the outpatient clinic for movement disorders at the University of Kiel.

Description

Inclusion Criteria:

  • Diagnosis of Parkinson's Disease, stage Hoehn & Yahr 1.5-3
  • Ability to pause antiparkinsonian medication in the morning without relevant impairment
  • Capacity to give consent (determined in doubt by two independent neurologists, MOCA ≥18) and written informed consent.
  • Patients are between 50 and 80 years of age, with exceptions for a maximum of 5 additional patients enrolled per group
  • For stratification into patients with and without sweet craving, a 3-day dietary protocol should be completed once by the patients
  • Group I: increased hunger for sweets.
  • Group II: no increased hunger for sweets.

For the stratification into patients with and without increased hunger for sweets, participants are asked to answer the following questions:

  1. Do you have sudden attacks of cravings for sweets?
  2. Would you say that your consumption of sweet food has increased in recent years?
  3. Would you describe your consumption of sugary food as increased or excessive?

If one of the questions is answered with yes, participants will be assigned to group I, if all questions are answered with no, participants will be assigned to group II.

Exclusion Criteria:

  • Other significant neurological diseases primarily affecting the central nervous system (e.g., multiple sclerosis)
  • Diagnosis of diabetes mellitus or prediabetes
  • Use of medications that affect glucose metabolism, such as antidiabetics, glucocorticoids, ciclosporin, tacrolimus, sirolimus, beta-blockers, thiazide diuretics, beta-2 adrenoreceptor agonists, theophylline, Clozapine, olanzapine, paliperidone, quetiapine, risperidone, tricyclic antidepressants, mirtazapine, mianserin, carbamazepine, gabapentin, pregabalin, valproic acid, lithium, antiretroviral drugs, statins
  • cardiac or brain pacemakers

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

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.
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.
PD patients with craving for sweets
Diagnostic test: Oral Glucose Tolerance Test
Application of 82,5 g of glucose monohydrate solved in 300ml water
Other: Placebo Oral Glucose Tolerance Test
Application of 125mg sucralose solved in 300ml water
PD patients without craving for sweets
Diagnostic test: Oral Glucose Tolerance Test
Application of 82,5 g of glucose monohydrate solved in 300ml water
Other: Placebo Oral Glucose Tolerance Test
Application of 125mg sucralose solved in 300ml water

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
Concentration of Insulin in µU/mL
Time Frame: immediately before Application of oral glucose tolerance test and placebo as well as 30, 60, 90 and 120 minutes after application
Blood value
immediately before Application of oral glucose tolerance test and placebo as well as 30, 60, 90 and 120 minutes after application
Motor function
Time Frame: immediately before Application of oral glucose tolerance test and placebo as well as 30, 60 and 120 minutes after application
assessed by Unified Parkinson's Disease Rating Scale Part III, 0-132 points, higher points indicate worse motor function
immediately before Application of oral glucose tolerance test and placebo as well as 30, 60 and 120 minutes after application
Concentration of Blood Glucose in mg/dL
Time Frame: immediately before Application of oral glucose tolerance test and placebo as well as 30, 60, 90 and 120 minutes after application
Blood value
immediately before Application of oral glucose tolerance test and placebo as well as 30, 60, 90 and 120 minutes after application

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Cognitive function
Time Frame: immediately before Application of oral glucose tolerance test and placebo as well as 60 minutes after application
assessed by Montreal-Cognitive-Assessment-Test (MoCa), 0-30 points, higher points indicate better cognitive function
immediately before Application of oral glucose tolerance test and placebo as well as 60 minutes after application

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 Hospital Schleswig-Holstein

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.
University of Kiel

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.
September 1, 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.
December 1, 2025

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.
December 1, 2025

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 21, 2023

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.
August 10, 2023

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.
August 21, 2023

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.
September 22, 2025

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.
September 16, 2025

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.
September 1, 2025

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.
  • D 537/23

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings