Osteogenesis imperfecta (OI) is a heritable connective tissue disorder, predominantly characterized by bone fragility. In half of the patients, progressive hearing loss develops, which is associated with abnormal bony changes involving the middle ear ossicles and stapes footplate. In the present study, we investigated whether the development of hearing loss in OI may be related to the overall aberrant bone quality.
Following audiologic evaluation, 56 adult OI patients were classified as presenting normal hearing or conductive/mixed or pure sensorineural hearing loss. Areal bone mineral density (BMD) (aBMD) was measured using lumbar spine (LS) and whole body (WB) dual X-ray absorptiometry. By means of peripheral computed tomography, volumetric BMD (vBMD) and morphometric bone parameters were determined at distal and proximal radius, providing separate results for trabecular and cortical bone. The obtained bone parameters were compared between normal-hearing OI patients and those with either conductive/mixed or pure sensorineural hearing loss.
Z scores demonstrated decreased LS aBMD, WB aBMD, and trabecular vBMD in OI adults compared to the healthy population. Patients with conductive/mixed hearing loss had lower trabecular vBMD compared to those with normal hearing or pure sensorineural loss at both whole-group and between-relatives comparisons.
It is hypothesized that OI patients with lower BMD might be more susceptible to accumulating microfractures, which may interfere with the bone remodeling inhibition pathways in the temporal bone and, therefore, contribute to stapes footplate fixation and a conductive hearing loss component.