The prevalence of peripheral neuropathy in a population-based study of patients with type 2 diabetes in Sweden

Abstract

Aims To assess peripheral neuropathy following a standardized foot examination protocol in a representative population-based cohort of subjects with type 2 diabetes. Methods In a geographically defined population, aged 40–70 years with diabetes prevalence of 3.5% according to medical records, we investigated 156 type 2 diabetic subjects, 95% Caucasian, mean age 61.7±7.2 years, duration of diabetes 7.0±5.7 years, and HbA 1c 7.3±2.4% (6.4% Mono-S), by questionnaires, clinical examinations, blood sampling, and review of medical records. Foot examination included clinical signs of peripheral neuropathy and tests of sensibility with monofilament, tuning fork, and assessments of the vibration perception thresholds (VPT). Results Peripheral autonomic neuropathy (PAN) as judged by two or more signs of dysfunction was the most common and affected 43%. The prevalence of peripheral sensory neuropathy (PSN) was 15% by monofilament, 24% by tuning fork, and 28% by VPT expressed as ZscoreVPT ≥2.0 S.D. Twenty-nine percent had a VPT ≥25 V. Signs of peripheral motor neuropathy (PMN) affected 15%. Peripheral neuropathy, at least one variable, affected 67%, whereas 25% were affected by more than one variable of neuropathy, i.e., polyneuropathy. Exclusion of other identified causes for neuropathy than diabetes reduced the prevalence of diabetic polyneuropathy to 23%. Concurrent diabetic complications were 29% for retinopathy, 14% for incipient nephropathy, and 8% for overt nephropathy. The prevalence of macrovascular complications was 62% for CVD, 26% for PVD, and 11% for cerebrovascular lesion (CVL). Conclusion Peripheral neuropathy was common in this representative type 2 diabetes population. Clinical signs of PAN were the most frequent followed by diminished perception of vibration and touch.