Kynurenine Pathway in Parkinson's Disease

NCT ID: NCT07272564

Last Updated: 2025-12-09

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-05-15
• Study Completion Date: 2023-06-18

Brief Summary

Parkinson's disease is a slowly progressing disease that affects the motor and non-motor functions of an individual. Periodontitis is an inflammatory chronic disease resulting in the destruction of tooth supporting structures. Inflammation has been identified as an important factor in both diseases. Given this common mechanism, the question arises as to how they may affect each other when both diseases occur together. In this study, we compared the metabolism of tryptophan, a natural amino acid of the human body, and observed whether such a process provides a biological link between periodontitis and Parkinson's disease. We extracted the saliva and blood samples of patients of Parkinson's disease and periodontitis, patients of periodontitis and healthy human beings. Comparisons between the three were made, and it was found that levels of some metabolites of tryptophan were higher in the patients of both diseases. These findings raise the possibility of a close biological connection between periodontal and brain health. Through an increased understanding of this connection in the future, new approaches for diagnosis and treatment of Parkinson's disease and periodontitis may be developed.

Detailed Description

Saliva and serum samples were collected from 20 Stage III, Grade B periodontitis patients with PAD (Parkinson+periodontitis group) and without PAD (periodontitis group), and 20 periodontally and systemically healthy (control group). Samples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry. Clinical periodontal parameters [plaque index (PI), probing pocket depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP)] were recorded.

Conditions

Periodontal Diseases; Inflammation

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Active Comparator

Saliva and serum collection of patients and samples molecules analysis

Group Type: ACTIVE_COMPARATOR

Saliva and serum sampling

Intervention Type: OTHER

Saliva were collected to analyze the selected markers as unstimulated samples during the early hours of the day. The saliva was centrifuged and then transferred into Eppendorf tubes. Venous puncture was performed after saliva collection and 10 mL of blood samples were collected by qualified staff from each participant. Saliva and serum were then stored at -80 °C until analysis.

Experimental

Samples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry. Clinical periodontal parameters \[plaque index (PI), probing pocket depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP)\] were recorded.

Group Type: EXPERIMENTAL

Saliva, serum and GCF sampling

Intervention Type: OTHER

Saliva were collected to analyze the selected markers as unstimulated samples during the early hours of the day. The saliva was centrifuged and then transferred into Eppendorf tubes. Venous puncture was performed after saliva collection and 10 mL of blood samples were collected by qualified staff from each participant. Saliva and serum were then stored at -80 °C until analysis.

Interventions

Saliva and serum sampling

Saliva were collected to analyze the selected markers as unstimulated samples during the early hours of the day. The saliva was centrifuged and then transferred into Eppendorf tubes. Venous puncture was performed after saliva collection and 10 mL of blood samples were collected by qualified staff from each participant. Saliva and serum were then stored at -80 °C until analysis.

Intervention Type: OTHER

Saliva, serum and GCF sampling

Saliva were collected to analyze the selected markers as unstimulated samples during the early hours of the day. The saliva was centrifuged and then transferred into Eppendorf tubes. Venous puncture was performed after saliva collection and 10 mL of blood samples were collected by qualified staff from each participant. Saliva and serum were then stored at -80 °C until analysis.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• systemically healthy

• clinical diagnosis of periodontitis
• clinical diagnosis of periodontal health

Exclusion Criteria

• history of regular use of systemic antibiotics anti-inflammatory, or antioxidant drugs (previous 3 months)

• nonsurgical periodontal treatment (previous 6 months)
• surgical periodontal treatment (previous 12 months)
• presence of<10 teeth
• current medications affecting gingival health (calcium channel blockers, phenytoin, cyclosporine, and hormone replacement therapy)
• diabetes
• diagnosis of rheumatoid arthritis
• pregnancy
• lactating
• smoking
• excessive alcohol consumption.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 75 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Medipol University

OTHER

Sponsor Role: lead

Responsible Party

Melis Yilmaz

Assistant Prof Dr

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Istanbul Medipol University, School of Dentistry

Istanbul, Fatih, Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

1082

Identifier Type: -

Identifier Source: org_study_id