Plasma reactive oxygen species levels are correlated with severity of age-related hearing impairment in humans

Abstract

To investigate the relationship between plasma reactive oxygen species (ROS) levels and severity of age-related hearing impairment in humans. We recruited 302 adult subjects aged 40–77 years with normal or symmetrical sensorineural hearing loss. The association of plasma ROS levels on pure tone average of low frequencies (PTA-low) and pure tone average of high frequencies (PTA-high) were analyzed. Luminol-dependent chemiluminescence signals, which reflect hydrogen peroxide (H2O2), hypochlorite (HOCl/OCl−) and hydroxyl radicals (•OH) levels, showed significant positive association with PTA-low and PTA-high after adjusting for age, gender, central obesity, systemic diseases, and health-related habits (smoking, drinking, antioxidant intake). Lucigenin-dependent chemiluminescence signals, which mainly reflect superoxide anion (O2•−) levels, showed significant positive association with PTA-low, but not with PTA-high after adjusting for other variables. We concluded that plasma ROS levels were associated with severity of age-related hearing impairment in humans. Various ROS may differently affect auditory dysfunctions.