Purpose: Research indicates that rheumatic disorders are accompanied by decreased chemosensory function. The present study aimed to specifically evaluate this issue in patients with rheumatoid arthritis (RA).
Methods: 212 RA patients (43 men, 169 women, mean age 59 ± 13.3 years), and 30 healthy controls (10 men, 20 women, mean age 40 ± 15.3 years), were included in this study. Chemosensory measurements consisted of olfactory testing using the "Sniffin' Sticks" test battery (with odor thresholds, odor discrimination and odor identification; OT, OD, OI) and gustatory testing on a suprathreshold and a quasi-threshold level using "taste sprays" and "taste strips", respectively. In addition, inflammatory markers (erythrocyte sedimentation rate, C-reactive protein) and RA autoantibodies (anti-cyclic citrullinated peptides, RA factors) were evaluated.
Results: Olfactory measurements showed 4% of the RA patients functionally anosmic and 40% hyposmic. RA patients scored significantly lower in suprathreshold olfactory tests (OD, OI) compared to controls (OI: 12.5 ± 2.5 vs. 14.1 ± 1.3; OD: 11.3 ± 2.7 vs. 12.9 ± 1.7). In addition, RA patient had decreased taste function compared to healthy individuals (10.4 ± 2.6 vs. 11.7 ± 1.7). Chemosensory function did not correlate with parameters related to the severity of disease.
Conclusion: Chemosensory function (taste, OD and OI) appears to be decreased in RA patients. In contrast, OT was not affected. Changes in chemosensory function seem to be independent of disease parameters such as duration of disease or disease activity.
Keywords: Olfaction; Olfactory function; Rheumatoid arthritis; Rheumatoid disorder; Taste.