Effect of Lowered Bone Mineral Density on the Outcomes of Audiological Tests: A Preliminary Study

Abstract

Introduction: Calcium ions are important for efficient release of neurotransmitters during the transduction process in cochlea. It also plays a pivotal role in recycling of potassium ions. A deficiency in optimal functioning of calcium, which is seen in osteopenia and osteoporosis, could therefore hinder the recycling of K+ ions and cause dysfunction in the neurotransmitter release and thereby sensorineural hearing loss. The deficiency in the bone mineral density (BMD) can also result in microfractures in the middle ear bones and thereby affect its transmission properties. However, few studies have investigated the audiological findings in osteoporosis and none in osteopenia. Therefore, the present study aimed at assessing the effect of lowered BMD on the outcomes of the audiological tests. Method: The study incorporated 11 participants with osteoporosis, 12 with osteopenia, and 12 having normal BMD. All the participants underwent detailed structured case history, pure-tone audiometry, speech audiometry, immittance evaluation, and distortion-product otoacoustic emission (DPOAE). Results: There was a trend toward increase in pure-tone average and speech recognition threshold (SRT) and reduction in speech identification scores in the two clinical groups than the controls; however, this was significant only for SRT (P < 0.05). The osteoporosis group revealed significantly higher proportions of ears with absent acoustic reflexes and DPOAEs than control group and osteopenia group. Conclusion: The findings point to the detrimental impact of reduction in BMD on the entire auditory periphery. Therefore, the audiological evaluation should consist of tests capable of evaluating the auditory system functioning at different levels when evaluating persons with osteopenia or osteoporosis.