Objective: This study was designed to investigate the role of zinc administration in treatment of tinnitus.
Study design: Randomized, prospective, placebo-controlled study.
Setting: Patients with tinnitus were admitted to the ear, nose, and throat clinic of the authors' hospital.
Patients: Patients with tinnitus with no know pathologic conditions of the ear, nose, and throat; the mean age of 28 patients receiving zinc was 51.2 years, and that of 13 patients given placebo was 55 years.
Intervention: Blood zinc levels were measured. Frequency was detected by audiometry, and loudness of tinnitus was screened by tinnitus match test. A questionnaire that scored tinnitus subjectively between 0 and 7 was given to patients before zinc treatment. After 2 months of treatment (zinc 50 mg daily to zinc group, placebo pill containing starch to placebo group), all of the tests were performed again. There was no difference in age, sex, duration of tinnitus, and affected ears between the patients treated with zinc and those treated with placebo. Blood zinc levels were lower than normal in 31% of patients before treatment.
Main outcome measures: A decrease in tinnitus loudness by at least 10 dB was accepted as clinically favorable progress. A decrease of more than 1 point in subjective tinnitus scoring was accepted as valid.
Results: Clinically favorable progress was detected in 46.4% of patients given zinc. Although this decrease was not statistically significant, the severity of subjective tinnitus decreased in 82% of the patients receiving zinc. The mean of subjective tinnitus decreased from 5.25 +/- 1.08 to 2.82 +/- 1.81 ( < 0.001). However, the decrease in severity of the tinnitus was not significant in patients receiving placebo.
Conclusion: It can be concluded that patients with tinnitus may have low blood zinc levels (31%) and clinical and subjective improvement can be achieved by oral zinc medication. However, it remains to be seen whether the longer duration of treatment has more significant results.