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

NCT05998772 | Recruiting

• 1 other identifier: D 537/23
• Study Type: observational
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Parkinson Disease; Nutritional and Metabolic Diseases; Sugar Intake

Outcome Measures

Primary Outcomes (3)

• Concentration of Insulin in µU/mL

  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

  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

  Blood value

  immediately before Application of oral glucose tolerance test and placebo as well as 30, 60, 90 and 120 minutes after application

Secondary Outcomes (1)

• Cognitive function

  immediately before Application of oral glucose tolerance test and placebo as well as 60 minutes after application

Study Arms (2)

PD patients with craving for sweets

Diagnostic Test: Oral Glucose Tolerance Test; Other: Placebo Oral Glucose Tolerance Test

PD patients without craving for sweets

Diagnostic Test: Oral Glucose Tolerance Test; Other: Placebo Oral Glucose Tolerance Test

Interventions

Oral Glucose Tolerance Test DIAGNOSTIC_TEST

Application of 82,5 g of glucose monohydrate solved in 300ml water

PD patients with craving for sweets; PD patients without craving for sweets

Placebo Oral Glucose Tolerance Test OTHER

Application of 125mg sucralose solved in 300ml water

PD patients with craving for sweets; PD patients without craving for sweets

Eligibility Criteria

• Age: 50 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• 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.

You may qualify if:

• 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:
• Do you have sudden attacks of cravings for sweets?
• Would you say that your consumption of sweet food has increased in recent years?
• 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.

You may not qualify if:

• 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

Sponsors & Collaborators

• University Hospital Schleswig-Holstein: lead
• University of Kiel: collaborator

Study Sites (1)

Department for Neurology, University of Kiel

Kiel, 24118, Germany

RECRUITING

MeSH Terms

Conditions

Parkinson Disease; Nutritional and Metabolic Diseases

Interventions

Glucose Tolerance Test

Condition Hierarchy (Ancestors)

Parkinsonian Disorders; Basal Ganglia Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Movement Disorders; Synucleinopathies; Neurodegenerative Diseases

Intervention Hierarchy (Ancestors)

Blood Chemical Analysis; Clinical Chemistry Tests; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Techniques, Endocrine; Investigative Techniques

Central Study Contacts

Eva Schäffer, MD

CONTACT

004943150023983; eva.schaeffer@uksh.de

Julienne Haas, MD

CONTACT

julienne.haas@uksh.de

Study Design

• Study Type: observational
• Observational Model: CASE CROSSOVER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: July 21, 2023
• First Posted: August 21, 2023
• Study Start: September 1, 2023
• Primary Completion: December 1, 2025
• Study Completion: December 1, 2025
• Last Updated: September 22, 2025

Record last verified: 2025-09

Locations

DE (1)