NCT07272564

Kynurenine Pathway in Parkinson's Disease

Periodontal Inflammation and Tryptophan-Kynurenine Metabolism in Parkinson's Disease

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 60 (actual)
• Sponsor: Medipol University · Academic / Other
• Sex: All
• Age: 18 Years – 75 Years
• Healthy volunteers: Accepted

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

Interventions

Type	Name	Description
OTHER	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.
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.

Timeline

• Start date: 2022-05-15
• Primary completion: 2023-01-10
• Completion: 2023-06-18
• First posted: 2025-12-09
• Last updated: 2025-12-09

Locations

1 site across 1 country: Turkey (Türkiye)