Hearing thresholds were studied in 53 patients with insulin-dependent diabetes mellitus (IDDM) and 42 randomly selected non-diabetic control subjects, aged between 20 and 40 years. The hearing level tended to be worse in diabetic patients than in control subjects, but the differences were statistically significant only at frequencies of 6000 and 8000 Hz. Microvascular complications (retinopathy and nephropathy), and the duration of diabetes were associated with the elevated hearing thresholds. In contrast, poor metabolic control (high fasting blood glucose and glycated haemoglobin Alc) was not associated with increased hearing thresholds. The changes caused by diabetic neuropathy appeared simultaneously with microvascular complications and a long duration of the diabetes, and thus a causative role of diabetic neuropathy in the pathogenesis of elevated hearing thresholds remained unsolved. It was concluded that elevated sensorineural hearing thresholds at the frequencies of 6000 and 8000 Hz in patients with IDDM are probably caused by the long duration of diabetes and the microvascular complications associated with it.

The relationship between diabetes and senbsorineural hearing loss has been disputed. This study compares 44 insulin-dependent diabetics with 38 age and sex matched controls. All had pure tone and speech audiometry performed, with any diabetics showing sensorineural deafness undergoing stapedial reflecx decat tests. In 14 diabetics stapedial reflex tests showed no tone decay in any patient, but seven showed evidence of recruitment. Analysis of vaiance showed the diabetics to be significantly deafer than the control population.The hearing loss affected high frequencies in both sexes, but also low frequencies in the male. Speech discrimination scores showed no differences. Further analysis by sex showed the males to account for most of the differences. Analysys of the audiograms showered mostly a high tone loss. Finally duration of disbetes, insulin dosage and family history of diabtes were not found to have a significant effect on threshold.