What topics does this cannabis study cover?

This study covers research on: THC.

Where was this research published?

Published in Respiratory medicine on July 22, 2026.

THC use disorders linked to signs of small-airway dysfunction

Q: What did this research study find?

In the baseline cohort, *THC use disorders* were associated with **higher odds of spirometry-defined small airways dysfunction**, including an adjusted odds ratio of **1.94** using the main MMEF definition.

Association between small airways dysfunction and THC use disorders in the general Swiss population.

Respiratory medicine • July 22, 2026 • Highly Relevant

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AI Summary

This population-based study examined whether THC use disorders were associated with small airways dysfunction (SAD), a breathing abnormality detected through spirometry. In the baseline cohort of 2,826 people, participants with a THC use disorder were more likely to show SAD and had lower measurements of small-airway airflow, even after accounting for age, sex, smoking status, body mass index, and— in one analysis—high blood eosinophils. The reported associations included approximately twofold higher odds of SAD under the main adjusted definition.

Results in the follow-up cohort were less consistent: the association appeared in unadjusted analyses but did not persist after adjustment. Because this was an observational study, it cannot establish that THC use disorders cause small-airway problems. Still, the findings support screening for THC use when patients are being evaluated for unexplained small-airway abnormalities, and they suggest that respiratory health assessments should consider cannabis use alongside tobacco and other factors.

💡 Key Findings

In the baseline cohort, THC use disorders were associated with higher odds of spirometry-defined small airways dysfunction, including an adjusted odds ratio of 1.94 using the main MMEF definition.

Good

75%

Participants with THC use disorders had lower small-airway airflow measurements in the baseline cohort after adjustment for key factors.

Good

70%

The follow-up findings were less consistent: associations were present in unadjusted analyses but did not persist after adjustment.

Good

75%

The study supports considering THC-use screening during evaluation of small-airway abnormalities, but it does not prove that THC use causes the dysfunction.

High

80%

📄 Original Abstract

Small airways dysfunction (SAD) may be associated with Δ9-tetrahydrocannabinol (THC), increasing peripheral airway resistance and reactance. To assess the association between THC use disorders and the presence of spirometry-defined SAD. The dataset was derived from the Swiss urban cohort CoLaus|PsyCoLaus. SAD was defined by maximal mid-expiratory flow (MMEF) < 65% of predicted value (PV) or MMEF < lower limit of normal (LLN). THC use disorders were defined as the presence of any THC abuse or dependence as assessed using a semi-structured interview. Associations between THC use disorders and SAD were assessed using logistic regression adjusted for age, sex, smoking status and body mass index in model 1. We performed a model 2 adjusted for the same covariables and high blood eosinophils. Association of MMEF with THC use disorders was evaluated using linear regression with the model 1 and 2. In the baseline cohort (n = 2826), THC use disorders were associated with SAD defined as MMEF<65%PV (OR 2.08, CI95[1.34; 3.24] and MMEF < LLN (OR 2.37, CI95[1.30; 4.33]) and according to the unadjusted model. This association persisted with MMEF<65%PV definition (OR 1.94, CI95[1.21; 3.09] in model 1, OR 1.95 CI95[1.22-3.12] in model 2). In the follow-up cohort (n = 1841), SAD defined as MMEF<65%PV or MMEF < LLN was associated with THC use disorders only in the unadjusted model (OR 1.83, CI95[1.01; 3.32] and OR 3.31, CI95[1.45; 7.56]). THC use disorders were associated with lower MMEF (ml/s and z-score) in the baseline cohort in model 1 and 2. THC use disorders seemed to be associated with an increased risk of spirometry-defined SAD and lower small airways spirometric value in this population-based cohort, highlighting the need for screening of THC in patients investigated for SAD.

Paper Type

📄 Research

Publication

Journal: Respiratory medicine
Published: July 22, 2026
PMID: 42486376
DOI: 10.1016/j.rmed.2026.109054

Authors (5)

Kevin Nguyen Faculty of Biology and Medicine, University of Lausanne (UNIL), Lausanne, Switzerland.
Marie-Pierre F Strippoli Psychiatric Epidemiology and Psychopathology Research Center, Department of Psychiatry, Lausanne University Hospital (CHUV), and University of Lausanne (UNIL), Prilly, Lausanne, Switzerland.
Martin Preisig Psychiatric Epidemiology and Psychopathology Research Center, Department of Psychiatry, Lausanne University Hospital (CHUV), and University of Lausanne (UNIL), Prilly, Lausanne, Switzerland.
Christophe von Garnier Division of Pulmonology, Department of Medicine, Lausanne University Hospital (CHUV), and University of Lausanne (UNIL), Lausanne, Switzerland.
Brice Touilloux Division of Pulmonology, Department of Medicine, Lausanne University Hospital (CHUV), and University of Lausanne (UNIL), Lausanne, Switzerland; Division of Pulmonology, Department of Medicine and Specialties, Fribourg Hospital and University of Fribourg, Fribourg, Switzerland. Electronic address: brice.touilloux@unil.ch.