Clinical trial NCT06954662: A Targeted Amino Acid Supplement for People With Parkinson's Disease
Official title: Comparison of Whey Protein and Amino Acid Supplementation on Amino Acid and Levodopa Concentrations in People With Parkinson's Disease
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: EARLY_PHASE1
Conditions: Parkinson Disease, Idiopathic
Keywords: Nutrition
Amino acid supplementation
Parkinson disease
Lead sponsor: UConn Health
Sponsor class: OTHER
First posted: 2025-05-01
Enrollment: 15
Sex: ALL
Minimum age (years): 55
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: This is a prospective, double-blind, randomized control trial with a repeated measures design in a single group.
Primary purpose: SUPPORTIVE_CARE

Brief summary: The goal of this clinical trial is to learn if an amino acid supplement that is specifically made for people with Parkinson disease can improve nutrition without interfering with dopamine medication in people living with Parkinson disease. The main question it aims to answer is:

• Does an amino acid supplement that is specifically made for people with Parkinson disease have short-term improvements in nutrition deficiencies, while minimally interfering with Parkinson disease medication?

Researchers will compare the short-term effects of this specialized nutrition supplement to a supplement that is available for everyone to purchase in a store (whey protein supplement-a milk by-product) and to an inactive supplement. Researchers will then check for the indicators of nutrition levels and the presence of dopamine medication in the blood. Researchers will also assess mood and movement abilities in participants.

Participants will be asked to:

* attend 4 study visits over the course of 4 weeks (initial orientation visit plus 3 intervention visits).
* drink one of the 3 supplements (supplements will be mixed into water to create a beverage) at each of the 3 intervention visits.

  * participate in blood drawings and mood and movement assessments at each of the intervention visits.
  * engage in a phone call after each intervention visit to determine any delayed responses.

Detailed description: This is a prospective, double-blind, randomized control trial with a repeated measures design. After being screened via phone screens and completing an initial visit that includes additional in person screening and the collection of descriptive information, participants will be invited to take part in three experimental sessions. On three separate days participants with idiopathic Parkinson's Disease and taking a stable dose of dopamine replacement medication, 2-3 hours after a standardized low-protein meal, will orally take a habitual dose of L-Dopa medication and then engage in one of the three interventions 1) WP-S: whey protein supplement (20 g), 2) AA-S: targeted amino acid supplement (equivalent amino acid load to whey protein beverage) 3) CON-S: an isonitrogenous placebo beverage (equivalent amino acid load to whey protein beverage), prescribed in a randomized and counterbalanced manner. Prior to, and up to 3 hours after medication, blood samples will be collected every 15 min for 90 min and every 30 min thereafter and then analyzed to determine circulating L-dopa and amino acid profiles using high-performance liquid chromatography. During this observation period changes in both motor (Movement Disorder Society-Unified Parkinson's Disease Rating Scale Part 3 (MDSUPDRS III), finger tapping, and Timed Up and Go Test) and non-motor disease symptoms (Profile of Mood State with component analysis of depression, fatigue, and anxiety) will be measured every 30 minutes.

All supplements will be provided for the study in coded prepackaged envelopes by an independent nutritional supplement company based on the formulas provided below, to ensure double blinding.

Whey Protein Supplement (WP-S): Whey protein is one of the primary proteins found in all dairy products. It is a complete protein as it contains all the essential amino acids. A previous investigation has been performed looking at the long -term (6 months) effects of whey protein supplementation on health and disease symptoms of people with Parkinson's Disease. This study validated the safety and efficacy of whey protein supplementation in people with Parkinson's Disease, but a non-significant increase in disease symptoms (during medication off time) was reported. Similar to this previous study, we will use a standard 20 g dose of whey protein.

Targeted Amino Acid Supplement (AA-S): Previous studies have investigated the long-term (6 months) effects of amino acid supplementation on health and disease symptoms of people with Parkinson's Disease. The previous whey protein study, and the previous amino acid supplement study, validated the safety and efficacy of an amino acid supplement in people with Parkinson's Disease but a non-significant increase in disease symptoms (during medication off time) was reported. However, the supplement in these studies was not designed to minimize the components which could interfere with levodopa medication.

In contrast, the AA-S used in the present study was designed off the amino acid composition of WP-S, but then was modified to minimize interference with levodopa by reducing the quantity of amino acids which are known to interfere with levodopa (large neutral amino acids), which collectively resulted in a 59% reduction in competing amino acids. Additionally, the concentrations of other non-competing amino acids were modified in order to fill the previously identified nutritional deficiency observed in people with PD.

Isonitrogenous Placebo Supplement (CON-S): The control supplement used in this study is an isonitrogenous placebo beverage. This supplement will consist of an inert amino acid (alanine) with the same amino acid load as the WP-S and AA-S (16.2 g).

Eligibility criteria: Inclusion Criteria:

* diagnosis of idiopathic Parkinson disease by patient report
* 55 years or older
* Has been using dopamine replacement medication (e.g. levodopa) for at least 2 years.
* On a stable dose of dopamine replacement medication for at least 3 months with no plans for change in the next two months.

Exclusion Criteria:

* Apparent cognitive impairment as determined by phone screening (TICS)
* Diagnosis of Parkinsonism or atypical Parkinson's Disease
* Are prescribed a dopamine antagonist
* Any unstable medical condition
* Any known bleeding disorder or currently taking blood thinners
* Using deep brain stimulation
* Gastric or bowel resection surgery

Primary outcomes:
measure: Circulating levodopa
timeFrame: study session 2 (Week 2), 3 (Week 3), and 4 (Week 4). Each session will last approximately 3-4 hours.
measure: Circulating amino acids concentrations
timeFrame: Session 2 (Week 2), Session 3 (Week 3), Session 4 (Week 4)
Secondary outcomes:
measure: Unified Parkinson Disease Rating Scale, Part III
timeFrame: This test will be performed prior to medication (Pre/+0 minutes) and at the end of testing (+180 minutes) at each of the 3 intervention sessions (Session 2/Week 2, Session 3/Week 3, Session 4/Week 4)
measure: Timed Up and Go Test
timeFrame: This test will be performed every 30 minutes (+0, +30, +60, +90, +120, +150, and +180 minutes) at each of the intervention sessions (Session 2/Week 2, Session 3/Week 3, Session 4/Week 4).
measure: Abbreviated Profile of Mood State
timeFrame: This test will be performed prior to medication (Pre/+0 minutes) and at the end of testing (+180 minutes) at each intervention session.
measure: 30 second Finger Tapping
timeFrame: This test will be performed every 30 minutes (+0, +30, +60, +90, +120, +150, and +180 minutes) at each intervention session
Other outcomes:
Locations:
city: Farmington
country: United States
facility: UConn Health, Clinical Research Center
state: Connecticut
Study officials:
affiliation: University of Connecticut
name: Cristina Colon-Semenza, PT, MPT, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: University of Connecticut
name: Jacob Earp, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Earp JE, Colon-Semenza C, LoBuono DL. Considerations for developing a targeted amino acid supplement for people with Parkinson's disease that promotes health while accounting for pathophysiology and medication interference. Nutr Rev. 2023 Jul 10;81(8):1063-1076. doi: 10.1093/nutrit/nuad008.