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

NCT07237958 — Not applicable, Completed, 40 participants, Umeå University

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

Registry	NCT07237958, acronym DINOSE
Status	Completed
Phase	Not applicable
Study type	Interventional; randomized, crossover, masking: quadruple, diagnostic
Enrollment	40 (Actual)
Sponsor	Umeå University (Other); collaborators: University Hospital, Umeå, University of Eastern Finland, Czech Academy of Sciences
Conditions	Alzheimer Disease (AD), Dementia Alzheimer Type, Air Pollution Exposure
Interventions	Diesel Exhaust Particles, Filtered air (Other)
Dates	start 2019-02-01, primary completion 2023-05-12, completion 2023-05-19, first posted 2025-11-20, last updated 2025-11-20
Locations	1 site in Sweden

-Summary

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.

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+Arms and interventions

Arm	Type	Interventions	Description
Exposure to diesel exhaust	Active comparator	Other: Diesel Exhaust Particles	The participants will be exposed in an exposure chamber for diesel exhaust in a concentration of 300 µg/m³ for one hour.
Exposure to filtered air	Placebo comparator	Other: Filtered air	The participants will be exposed in an exposure chamber to filtered air for one hour.

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

+Outcome measures

Primary outcomes

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

Secondary outcomes

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

+Eligibility

Sex: All, ages: 20 Years to 70 Years, accepts healthy volunteers

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

+Locations (1)

Facility	City	Country	Status
Umeå Univeristy	Umeå	Sweden

+Publications

Martikainen MV, Aakko-Saksa P, van den Broek L, Cassee FR, Carare RO, Chew S, Dinnyes A, Giugno R, Kanninen KM, Malm T, Muala A, Nedergaard M, Oudin A, Oyola P, Pfeiffer TV, Ronkko T, Saarikoski S, Sandstrom T, Schins RPF, Topinka J, Yang M, Zeng X, Westerink RHS, Jalava PI. TUBE Project: Transport-Derived Ultrafines and the Brain Effects. Int J Environ Res Public Health. 2021 Dec 28;19(1):311. doi: 10.3390/ijerph19010311. PMID 35010571

+Study documents

Study Protocol (PDF, 2021-06-17)
Informed Consent Form (PDF, 2021-06-17)

My Notes

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