Use of nonsteroidal anti-inflammatory drugs and poor olfaction in women

It is unclear whether regular use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with poor olfaction in older adults.

We selected 4020 participants, aged 50 to 79 years in 2018, from 36,492 eligible participants in the National Institute of Environmental Health Sciences Sister Study, according to their self-reported olfaction status. Of these, 3406 women completed the 12-item Brief Smell Identification Test. We defined poor olfaction as a test score ≤9 in the primary analysis. We then estimated odds ratios (ORs) and 95% confidence intervals (CIs) from weighted logistic models, accounting for the study design, missing exposures/outcomes, and covariates.

Overall, NSAID use was not associated with poor olfaction. However, we found evidence for potential multiplicative interactions. Specifically, the OR comparing regular versus never use of aspirin was 1.8 (95% CI, 1.1-3.2) among women who had not regularly used nonaspirin NSAIDs, while the corresponding OR was 0.8 (95% CI, 0.5-1.2) among nonaspirin NSAID users (P for interaction = 0.016). Similar results were seen for ibuprofen alone versus ibuprofen with other NSAID use (P for interaction = 0.010). Among women using either drug alone, associations with poor olfaction increased with increasing duration and cumulative dose. Post hoc analyses showed that the interactions could not be readily explained by potential biases. Other NSAIDs were not associated with olfaction.

Long-term regular use of aspirin or ibuprofen was associated with poor olfaction among women who never regularly used other types of NSAIDs. These preliminary findings warrant independent confirmation.