Evaluation of olfactory function in adults with primary hypothyroidism.

BACKGROUND

Sufficient clinical data are not available on the effect of hypothyroidism on olfactory function in adults. In this study, we aimed to evaluate the olfactory function of adult patients diagnosed with primary hypothyroidism.

METHODS

Forty-five patients aged between 18 and 60 years who were diagnosed with clinical primary hypothyroidism and 45 healthy controls who had normal thyroid function tests were included in the study. Sniffin' Sticks olfactory test results of the 2 groups were compared. The relationships between thyroid function tests and olfactory parameters were evaluated.

RESULTS

Odor threshold, identification, and discrimination scores of the hypothyroid group were significantly lower than those of the control group (p < 0.001). A significant positive correlation was detected between free triiodothyronine (FT3) levels and odor threshold, identification, and discrimination scores (p < 0.001). There was no significant relationship between thyroid-stimulating hormone (TSH) or free thyroxine (FT4) levels and olfactory parameters.

CONCLUSION

Our study revealed diminished olfactory function in adults with hypothyroidism. FT3 levels were found to have a more significant relationship with olfactory parameters than TSH or FT4 levels.