Prevalence and impact on quality of life of peripheral neuropathy with or without neuropathic pain in type 1 and type 2 diabetic patients attending hospital outpatients clinics

Aims. - Diabetic polyneuropathy (DPN) without or with neuropathic pain (DPN-P) is one of the most frequent complications of diabetes. To better delineate their respective prevalences, we conducted a cross-sectional study that included 1111 patients (767 type 2 and 344 type I diabetic patients) followed up in diabetic outpatients clinics. The association of DPN and DPN-P with other diabetic complications, the impact on quality of life (QoL) and pain management were also investigated. Methods. - Two validated tools (Neuropen (R) and the DN4 questionnaire) were used to diagnose the two conditions. Pain intensity was measured using a visual analogue scale, and participants completed the 12-item Short-Form Health Survey to evaluate the physical and mental components of QoL. Univariate and multivariate models were used for the statistical analyses. Results. - The prevalence of DPN was 43% (95% CI 40.1-45.9), and was higher in type 2 (50.8%) than in type 1 (25.6%) diabetic patients. The prevalence of DPN-P was 14% (95% CI 12.1-16.2) which, again, was higher in type 2 (17.9%) than in type 1 (5.8%) patients. These prevalences both increased with age and diabetes duration. Nephropathy, obesity, low HDL cholesterol and high triglyceride levels were independently associated with DPN and/or DPN-P. Physical and mental components of QoL were significantly altered by DPN-P, but not DPN. Only half of the DPN-P patients were using analgesic treatment, while 28% were using anticonvulsants or antidepressants. Conclusion. - DPN and DPN-P are frequent complications of diabetes, especially in type 2, and can be identified with inexpensive and easy-to-use screening tools. Despite its profound impact on QoL, DPN-P remains undertreated. (C) 2009 Elsevier Masson SAS. All rights reserved.