The role of plasma melatonin and vitamins C and B12 in the development of idiopathic tinnitus in the elderly.

BACKGROUND To determine the correlation between plasma levels of melatonin, vitamin C and vitamin B12 and the presence of tinnitus among elderly subjects with unexplained subjective tinnitus. METHOD Prospective involving apparently healthy elderly with subjective tinnitus and those without. Plasma levels of melatonin, vitamin C and vitamin B12 were determined using high performance liquid chromatography and correlation determined by comparing subjects with and without tinnitus. RESULT There were 139 elderly subjects (78 females and 61males), the mean(SD) range of the age was 66.9years (0.77) 60-98 years. Of these 58.3% had tinnitus. The mean (SD) range of the plasma levels of melatoninn was 11.2 pg/mL(4.2) 5.1 pg/mL - 30.2 pg/mL while that of Vitamin C was 0.7 µmol/L (0.1) 0.3 µmol/L - 1.2 µmol/L, and vitamin B12 was 43.0pmol/L (3.1) 25.4 pmol/L - 71.6pmol/L. Comparing the plasma levels of the markers between elderly with and those without tinnitus, the plasma levels of melatonin (p=0.01) and vitamin B12 (p=0.03) were significantly lower among the elderly with tinnitus compared to those without, while the difference in the plasma level of vitamin C (p=0.6) was not. CONCLUSION Low plasma melatonin and vitamin B12 have significant correlation with the development of subjective idiopathic tinnitus among the elderly. This finding suggests the need for the trial of correction of these markers in the reversal or control of tinnitus.