Skip to main content
OpenTrials
Completed

NCT Number: NCT07237958

Effects on the Olfactory Epithelium and the Olfactory Nerve 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.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Alzheimer Disease (AD) Air Pollution Exposure Alzheimer Disease Brain Diseases Central Nervous System Diseases Dementia Dementia Alzheimer Type Mental Disorders Nervous System Diseases Neurocognitive Disorders Neurodegenerative Diseases Tauopathies

Age range

20 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Umeå Univeristy

Umeå, 90185, Sweden

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Diesel Exhaust Particles

Other

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.

Filtered Air

Other

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

Primary outcomes

  1. 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.

Secondary outcomes

  1. 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.

Sponsors and collaborators

Lead sponsor

Umeå University

Other

Collaborators

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

Registry information

Official study title

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

Acronym: DINOSE

Important dates

Study start
2019
Primary completion
2023
Study completion
2023
First posted
Nov 20, 2025
Registry last updated
Nov 20, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.