Association Between Calcium Metabolism and Inner Ear Function: Evidence of Auditory and Vestibular Dysfunction in Primary Hyperparathyroidism

The aim of this study is to evaluate the vestibular and auditory functions of patients with primary hyperparathyroidism. (PHPT)
he experimental group composed of 25 patients with PHPT, and the control group composed of 25 age- and sex-matched healthy adults. The participants underwent a standardized audiovestibular assessment. The audiological battery included tympanometry, pure-tone audiometry (PTA), speech discrimination (SD), and speech reception threshold (SRT). Vestibular function was assessed with videonystagmography (VNG), video head impulse test (vHIT), and symptom burden was quantified using the Dizziness Handicap Inventory (DHI). In addition, a binary logistic regression analysis was performed to evaluate whether bone mineral density (BMD), parathyroid hormone (PTH), vitamin D, and calcium levels were associated with the presence of pathological saccades (0 = absent, 1 = present).
The groups were statistically similar in terms of sex distribution and age. Patients with PHPT exhibited significantly elevated pure-tone thresholds at 250-8000 hz and higher mean PTA and SRT values compared with controls, while mean SD scores were slightly lower but not statistically significant. VOR gains on vHIT were significantly reduced across all semicircular canals in the PHPT group, whereas VNG findings did not differ between groups. DHI total scores were also significantly higher in the PHPTgroup, indicating greater perceived vestibular disability. There was no significant association between BMD, PTH, vitamin D, or calcium levels and the presence of pathological saccades
PHPT is associated with subclinical auditory and vestibular dysfunction, likely mediated by disturbances in calcium and vitamin D metabolism, underscoring the importance of early evaluation and follow-up in this population.
In this prospective case–control study, we comprehensively evaluated auditory and vestibular function in patients with primary hyperparathyroidism (PHPT) with specific attention to calcium and vitamin D metabolism. Compared with age- and sex-matched controls, PHPT patients exhibited elevated hearing thresholds, reduced vestibulo-ocular reflex gains on vHIT, and higher DHI scores, while conventional VNG parameters did not differ. We also performed logistic regression including bone mineral density, parathyroid hormone, vitamin D, and calcium; none showed a significant association with pathological saccades. These findings suggest subclinical audiovestibular involvement in PHPT and highlight the potential value of routine screening in this population. This study is, to our knowledge, the first to demonstrate objective canal dysfunction on vHIT alongside subclinical hearing impairment in PHPT.