Abstract
The decline in the vibratory sense is one of the most important pathologic findings appearing in diabetic polyneuropathy. The vibratory sensory thresholds (VST) of 63 healthy persons and 139 diabetic patients were measured quantitatively by an electrically vibrated tuning fork and a vibrometer developed by us which indicate the VST in voltage. In both healthy persons and diabetic patients the VST of the index fingers and second toes showed an increase with the advancement of age. In the case of the vibratory sense of the fingers, the diabetic patient group showed a rise in the VST level compared with the healthy group, but this difference was small, while in the case of toes a significant difference in the VST level was indicated. The VST of 59 patients out of the same diabetic patient group were again measured five years later. The difference between the VST five years later and the previous VST values was taken to express degree of vibratory sense advancement, and its relationship with various factors was investigated. This degree of vibratory advancement showed a positive correlation with the mean fasting blood sugar and HbA1 (r=0.307, p<0.05; r=0.468, p<0.01 respectively) . It also showed a negative correlation with the toe peak wave measured by plethysmograph (r=-0.464, p<0.05) . It was, however, unrelated to the insulin response, serum lipid, obesity and presence of diabetic retinopathy. An examination was made to determine whether administration or non-administration of peripheral vasodilators or vitamin preparations caused any significant difference, but it seems that they could not prevent the aggravation of the vibratory sense over a comparatively long term of five years. From the above it is considered that glycemic control is of basic importance in preventing the decline in vibratory sense in diabetic patients.
