Significant hearing loss in Fabry disease: Study of the Danish nationwide cohort prior to treatment

BACKGROUND: Fabry disease (FD) is a lysosomal storage disorder resulting in systemic accumulation of globotriaosylceramide resulting in multi-organ dysfunction e.g. cerebral, cardiac, renal and audiologic complications. The audiologic involvement in FD has often been neglected; while not a lethal aspect of the disease, hearing loss can have a significantly negative impact on quality of life. OBJECTIVES: To investigate baseline hearing status of the Danish Fabry cohort prior to treatment, compared to sex- and age-expected hearing levels and correlating hearing to renal and cerebral findings. MATERIAL AND METHODS: Retrospective study of baseline hearing status of the Danish Fabry cohort (n = 83, 9–72 years). Air conduction and speech discrimination scores were assessed at 6 frequencies between 0.25–8 kHz bilaterally. Data were collected between 2001–2014 and compiled in STATA using multilinear mixed modelling for statistical evaluation. RESULTS: Hearing thresholds at all frequencies deviated from the expected thresholds of an otologically normal cohort (p<0.001) and ranged 0.5 to 1.5 standard deviations below expected values. In total 29 males and 54 females were included. Hearing loss was more pronounced in the higher frequencies. There was a trend of association between hearing loss and measured glomerular filtration rate (mGFR) (p = 0.084). No association was present between hearing loss and albuminuria (p = 0.90), Fabry related cerebral abnormalities (p = 0.84) and cardiac left ventricular mass index, (LVMi) (p = 0.67) independent of sex. Hearing thresholds were poorer for men compared to women (p = 0.001). Sex differences were present at 0.25, 4 and 8 kHz. CONCLUSION: Our findings demonstrated significant hearing loss in Danish FD patients before treatment initiation, being more profound than in otologically healthy individuals at all frequencies. Additionally, we observed no association between hearing loss and LVMi, albuminuria or FD cerebral abnormalities, with a trend of association to mGFR. SYNOPSIS: Patients with Fabrys disease have hearing loss of all frequencies and most prominently at high frequencies (4–8 kHz), with no association between the hearing loss and cerebral abnormalities, and cardiac mass but with a trend of association to measured glomerular filtration rate.