Low Thyroid-stimulating Hormone Levels Are Associated With Annoying Tinnitus in Adult Women: Korea National Health and Nutrition Examination Surveys

OBJECTIVE This study aimed to investigate the relationship between thyroid function and tinnitus. STUDY DESIGN A cross-sectional study. SETTING The Korean National Health and Nutrition Examination Survey from 2013 was used. PATIENTS AND INTERVENTIONS A total of 1,165 participants ≥ 40 years old who were surveyed for the presence of tinnitus and underwent thyroid function tests were included. The presence of discomfort from tinnitus was defined as annoying tinnitus. The control group included participants with "no tinnitus" or "no discomfort from tinnitus." The participants were divided into the annoying tinnitus group and the control group. MAIN OUTCOME MEASURES The associations of free thyroxine and thyroid-stimulating hormone (TSH) with annoying tinnitus were analyzed using logistic regression with complex sampling methods. Subgroup analyses were performed according to sex. RESULTS The low TSH level group had 2.35-fold greater odds of annoying tinnitus than the control group (95% confidence interval  = 1.10-5.12, p = 0.027). Even in patients with a normal free thyroxine level, a low TSH level was related to 2.78-fold higher odds of annoying tinnitus (95% confidence interval  = 1.21-6.38, p = 0.016). In subgroup analyses, this association was apparent in the female subgroup. The male subgroup did not show a relationship between low TSH levels and annoying tinnitus. CONCLUSIONS Subclinical hyperthyroidism was related to an increased risk of annoying tinnitus. This relationship was apparent in the female subgroup.