The Meaning of Dopaminergic Pathway in Sleep Breathing Disorders.

January 31, 2026 updated by: Joanna Smardz, Wroclaw Medical University

The Importance of Dopamine and Selected Polymorphisms Within the Genes of the Dopaminergic Pathway in Assessment of the Risk of Development and Severity of Sleep Breathing Disorders.

The participants in the study will be adult patients with suspected sleep-disordered breathing. A one-night polysomnography will be performed using the NOXA1 device (NOX Medical, Reykjavík, Iceland). During the polysomnographic examination, sleep, breathing, heart rate and activity of the masticatory muscles will be recorded. Blood sample will be taken from each of the participants qualified to the study and control group to determine the level of dopamine and used to perform genetic tests of selected single nucleotide polymorphisms occurring within the genes regulating the concentration of dopamine and genes encoding dopamine receptors.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

Sleep-disordered breathing (SDB) refers to a spectrum of abnormalities related to sleep. Obstructive sleep apnea (OSA) is the most common type of SDB and affects approximately one billion adults worldwide. Untreated OSA leads to significant comorbidities and increased mortality due to significantly increased risk of stroke and heart attack. Because of limited access to objective sleep studies and the fact that untreated OSA is a real risk factor premature death, the determination of possible organic reasons for its occurrence is a key aspect. The purpose of the study is to determine the importance of dopamine levels and selected single nucleotide polymorphisms within genes regulating the concentration of dopamine - the gene responsible for production of the enzyme catechol-O-methyltransferase (COMT) - rs4680 and rs6269 and genes encoding receptors dopamine (DRD1 - rs686, rs5327 and DRD2 - rs1800497) in assessment of the risk of development and advancement of SDB. The participants of the study will be adult patients hospitalized in the Department of Internal Diseases, Occupational Diseases, Hypertension and Clinical Oncology of the Wroclaw Medical University due to suspicion of SDB. One-night polysomnography study will be performed using the NOXA1 device (NOX Medical, Reykjavík, Iceland) at the Sleep Laboratory. During the examination parameters regarding sleep, breathing, heart rate and activity of the masticatory muscles will be recorded. The study group will consist of the participants in whom, on the basis of 3rd edition of the International Classification of Sleep Disorders of the American Academy of Sleep Medicine SDB will be recognized. Control group will consist of healthy participants matched in terms of age and sex. A blood sample will be collected from all participants to determine the level of dopamine and to perform genetic test of selected single nucleotide polymorphisms within the genes regulating the concentration of dopamine - the gene responsible for production the enzyme catechol-O-methyltransferase (COMT) - rs4680 and rs6269 and genes encoding dopamine receptors (DRD1 - rs686, rs5327 and DRD2 - rs1800497). Study group and control group will be compared and the results will be statistically analysed.

Study Type

Observational

Enrollment (Estimated)

100

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Poland
      • Wroclaw, Poland
        • Wroclaw Medical Uniwesity

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

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

Patients with suspicion of sleep-disordered breathing referred to the Department of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology operating at the Wroclaw Medical University. Healthy controls.

Description

Inclusion Criteria:

  • age between 18 and 80 years old
  • suspicion of sleep-disordered breathing

Exclusion Criteria:

  • age under 18
  • age over 80
  • severe disorders and systemic diseases (including genetical disorders)
  • neurological disorders
  • active inflammations
  • active cancer
  • severe mental disorders and retardation (including genetical)
  • taking drugs that could falsify polysomnography
  • confirmed alcoholism
  • drug addiction
  • pregnancy and breast feeding
  • treatment using or dependence on any painkillers and/or drugs and substances that may affect nervous, muscular and respiratory system functions
  • lack of consent to participate in the study

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
Intervention / Treatment
Study group
Participants with the diagnosis of sleep-disordered breathing
Diagnostic test: Polysomnography
Each of the patients will undergo polysomnography
Diagnostic test: Blood dopamine level measurement
In each of the patients blood dopamine level will be measured
Diagnostic test: Genetical test
Each of the patients will undergo genetical test focusing on selected single nucleotide polymorphisms within genes regulating the concentration of dopamine - the gene responsible for production of the enzyme catechol-O-methyltransferase (COMT) - rs4680 and rs6269 and genes encoding receptors dopamine (DRD1 - rs686, rs5327 and DRD2 - rs1800497).
Control group
Healthy participants without diagnosis of sleep-disordered breathing
Diagnostic test: Polysomnography
Each of the patients will undergo polysomnography
Diagnostic test: Blood dopamine level measurement
In each of the patients blood dopamine level will be measured
Diagnostic test: Genetical test
Each of the patients will undergo genetical test focusing on selected single nucleotide polymorphisms within genes regulating the concentration of dopamine - the gene responsible for production of the enzyme catechol-O-methyltransferase (COMT) - rs4680 and rs6269 and genes encoding receptors dopamine (DRD1 - rs686, rs5327 and DRD2 - rs1800497).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Relationship between sleep-disordered breathing and blood dopamine level.
Time Frame: June 1, 2023 - December 31, 2023
Each participant will undergo blood test focusing on the level of dopamine.
June 1, 2023 - December 31, 2023

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Relationship between sleep-disordered breathing and polymorphism within genes regulating the concentration and encoding receptors of dopamine.
Time Frame: June 1, 2023 - December 31, 2023
Each participant will undergo genetical blood test focusing on the polymorphisms within genes regulating the concentration of dopamine - the gene responsible for production of the enzyme catechol-O-methyltransferase (COMT) - rs4680 and rs6269 and genes encoding receptors dopamine (DRD1 - rs686, rs5327 and DRD2 - rs1800497).
June 1, 2023 - December 31, 2023

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Wroclaw Medical University

Investigators

  • Principal Investigator: Joanna Smardz, Ph.D, Wroclaw Medical University

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)

June 1, 2023

Primary Completion (Estimated)

May 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

May 25, 2023

First Submitted That Met QC Criteria

May 25, 2023

First Posted (Actual)

June 6, 2023

Study Record Updates

Last Update Posted (Actual)

February 3, 2026

Last Update Submitted That Met QC Criteria

January 31, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • WMU2/2023

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

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.

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