Age-related exacerbation in disease-associated olfactory disorders

BACKGROUND: Both the physiological degeneration linked to aging and the pathological changes resulting from diseases can impact olfactory function in the patients with olfactory disorder (OD). However, the epidemiological literature addressing the extent of aging's involvement to the diseases which causes OD is limited. Our study aimed to investigate how aging affects olfactory function in major causes of OD by employing psychophysical olfactory sensory testing. METHODOLOGY: Non-eosinophilic chronic rhinosinusitis (NECRS), eosinophilic chronic rhinosinusitis (ECRS), post-infectious OD (PIOD), post-traumatic OD, and idiopathic OD were identified as major contributors to OD. Retrospective data from 1986 patients were collected from our smell clinic. We utilized T&T olfactometer thresholds to assess quantitative olfactory function. Patients were categorized into age groups spanning every 10 years from their 20s to 80s, and we analyzed potential differences between age groups and diseases. Additionally, the odds ratio of severe OD was analyzed with respect to gender and age, categorizing patients into two groups: lower than 60 and over or equal to 60. RESULTS: A significant odds ratio was observed for elevated T&T average threshold with respect to age in the detection and recognition thresholds of patients diagnosed with NECRS, PIOD and idiopathic OD. In contrast, no significant odds ratio was observed in patients with ECRS or post-traumatic OD, regardless of age. CONCLUSION: Analysis of disease-specific OD revealed varying degrees of age-related physiological and disease-pathological across different conditions. These findings underscore the importance for clinicians to consider both age-related physiological changes and the specific disease pathology of the disease when diagnosing and managing OD, particularly in elderly patients.