Effects on the Olfactory Epithelium and the Olfactory Nerve From Exposure to Diesel Exhaust (DINOSE)

November 14, 2025 updated by: Ala Muala, Umeå University

Effects on the Olfactory Epithelium in the Nose and the Olfactory Nerve (Nervus Olfactorius) From Exposure to Diesel Exhaust

The goal of this study is to study the effect exposure to air pollution and its effect on development of dementia.

Does the diesel exhaust change the function of the olfactory system?

Have the exposures measurable effects on the sense of smell and cognitive ability?

Forty people are exposed to diesel exhaust exhaust and filtered air. The exposures are blinded and in a randomized order. Both groups undergo biopsies of the olfactory epithelium in the nose under local anesthesia after the exposures and after performing cognitive test.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

40

Phase

  • Not Applicable

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

  • Sweden
      • Umeå, Sweden, 90185
        • Umeå Univeristy

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

Description

Inclusion Criteria:

  • Healthy
  • non-smoker

Exclusion Criteria:

  • Allergic rhinitis
  • Asthma
  • Diabetes mellitus
  • Kidney or liver failure
  • Angina pectoris or previous ventricular arrhythmia
  • Systolic blood pressure >190 mmHg or <100 mmHg
  • Previous blood disease
  • Blood donation in the last three months prior to study start
  • Previous or ongoing tobacco smoking and exposure to air pollution in the workplace
  • Absence of informed consent

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

  • Primary Purpose: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Exposure to diesel exhaust
The participants will be exposed in an exposure chamber for diesel exhaust in a concentration of 300 µg/m³ for one hour.
Other: Diesel Exhaust Particles
During exposure to diesel exhaust, participants alternate between 15-minute periods of rest and exercise on an ergometer cycle with a workload that results in a minute ventilation of 20L/min/m² body surface area. Symptom recording is done every 30 minutes, following a routine based on a modified Borg scale.
Placebo Comparator: Exposure to filtered air
The participants will be exposed in an exposure chamber to filtered air for one hour.
Other: Filtered air
During exposure to filtered air, participants alternate between 15-minute periods of rest and exercise on an ergometer cycle with a workload that results in a minute ventilation of 20L/min/m² body surface area. Symptom recording is done every 30 minutes, following a routine based on a modified Borg scale

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diesel exhaust causes cellular dysfunction of the olfactory system
Time Frame: 3 years.
RNA sequencing and DNA methylation will be conducted to identify biomarkers for acute exposure to diesel exhaust.
3 years.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cognitive test
Time Frame: 3 years
Olfactory function well be evaluated by using "sniffin' sticks," and a Letter-Digit Substitution Test as a marker for cognitive processing speed.
3 years

Collaborators and Investigators

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

Sponsor

Umeå University

Collaborators

University of Eastern Finland
University Hospital, Umeå
Czech Academy of Sciences

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Helpful Links

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)

February 1, 2019

Primary Completion (Actual)

May 12, 2023

Study Completion (Actual)

May 19, 2023

Study Registration Dates

First Submitted

July 4, 2025

First Submitted That Met QC Criteria

November 14, 2025

First Posted (Actual)

November 20, 2025

Study Record Updates

Last Update Posted (Actual)

November 20, 2025

Last Update Submitted That Met QC Criteria

November 14, 2025

Last Verified

November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2018-438-31
  • X (Mirum Pharmaceuticals, Inc.)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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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