Polyneuropathy in Australian outpatients with type II diabetes mellitus

In order to determine the local prevalence of polyneuropathy among adult ou tpatients with type II (non-insulin-dependent) diabetes mellitus, we applie d a series of standardised measures to patients attending a multidisciplina ry diabetes clinic. The study group comprised 94 men and 15 women; mean age , 70.6 +/- 7.8 years; mean duration of diabetes, 11.7 +/- 10.1 years; and m ean HbA(1C), 8.3% +/- 1.7%. Neuropathy Symptom Scores greater than or equal to 1 were present in 97% of patients (mean, 3 +/- 2; range, 0-12), and 95% had Neuropathy Disability Scores greater than or equal to 2 (mean, 27 +/- 19; range, 0-87). 52% of men reported impotence. Autonomic dysfunction on c ardiovascular reflex testing was present in 46% of patients (39/84). Finger and toe vibration perception thresholds were greater than 3SD higher than mean thresholds measured in control subjects without diabetes in 43% and 58 % of patients, respectively Polyneuropathy, defined as lower limb sensory a nd motor nerve conduction velocity or latency outside mean +/- 2SD of that measured in age-matched controls, was present in 49% of patients (53/109). These results suggest that there is a high prevalence of polyneuropathy in Australian out-patients with type II diabetes mellitus, In this study, clin ical assessment using Neuropathy Disability Stores was not diagnostically u seful since only five patients had a normal score. Using nerve-conduction s tudies as the "gold standard" diagnostic criteria the best alternative test for the presence of polyneuropathy was toe vibration perception threshold (sensitivity 74%, specificity 56%). In view of the emerging evidence that i ntensive glycaemic control reduces the rate of progression of polyneuropath y, we recommend that patients with type II diabetes mellitus have nerve-con duction studies performed for early detection of this important complicatio n. (C) 1999 Elsevier Science Inc.