Factors related to the electric taste threshold in type 1 diabetic patients.

To specify the factors related to taste function in Type 1 diabetes mellitus, 50 diabetic out-patients and 50 control subjects paired for age and sex were screened for taste disorders. None of them consumed significant amounts of alcohol, smoked, or had disease or took drugs capable of altering taste. Taste was studied with electrogustometry, retinopathy was detected by fluorescein angiography, nephropathy by measurement of albuminuria and microalbuminuria, peripheral neuropathy by electroneurography and electromyography, and autonomic neuropathy by cardiovascular function tests. The electrogustometric threshold was, on average, significantly higher in the diabetic group (133 +/- 30 microA) than in the control group (29 +/- 9 microA; p less than 0.001). Electric hypogeusia (electrogustometric threshold greater than 100 microA) was found among 54% of the diabetic patients vs 2% of the control subjects (p less than 0.001). In the diabetic group, the electrogustometric threshold was associated with complications of diabetes, especially with peripheral neuropathy (210 +/- 24 vs 90 +/- 22 microA; p less than 0.001) and microalbuminuria (185 +/- 25 vs 86 +/- 21 microA; p less than 0.01). It was correlated with age (r = 0.37; p less than 0.01) and duration of diabetes (r = 0.52; p less than 0.001) but not with HbA1c (r = -0.04). Using multivariate analysis, duration of diabetes and peripheral neuropathy had the strongest association with taste impairment. These results support previous findings, suggesting that taste impairment is a degenerative complication of diabetes mellitus.