The impact of obstructive apnea sleep syndrome on chemical function.

Objective/hypothesis: To investigate the impact of obstructive sleep apnea syndrome (OSAS) on the olfactory and gustatory functions, and the potential mechanisms affecting olfactory and gustatory functions.

Materials And Methods: A total of 120 men between the ages of 41 and 70 (mean age (SD) = 56 ± 7.5) were divided into three groups according to polysomnography results: snoring group, mild to moderate OSAS group, and severe OSAS group. Olfactory and gustatory functions were evaluated by the Sniffin' Sticks test and the triple-drop method, respectively. Otorhinolaryngologic examination, as well as sleep and quality of life questionnaires, were completed by all subjects one day before or after polysomnography.

Results: There was a significant difference in odor thresholds (THR), odor discrimination (OD), odor identification (OI), thresholds-discrimination-identification (TDI) (p < 0.001, p < 0.001, p = 0.003, p < 0.001), and total taste score (p = 0.004, p = 0.021, p = 0.006) in all three groups. Of the subjects in the OSAS group, 43 (54%) exhibited olfactory dysfunction, including 18 subjects (45%) in the mild to moderate group and 25 subjects (63%) in the severe group. Significant negative correlations were found between all olfactory parameters and polysomnography parameters. Furthermore, a negative correlation was present between the total taste scores and the apnea-hypopnea index (AHI).

Conclusion: Men with OSAS exhibited impairment in olfactory and gustatory functions. Significant correlations were found between AHI and olfactory parameters, as well as between AHI and total taste scores.