Utility of DN4 questionnaire in assessment of neuropathic pain and its clinical correlations in Turkish patients with diabetes mellitus

Aim: We aimed to assess the utility of DN4 questionnaire (Douleur Neuropathique en 4 questions) to define the frequency and severity of neuropathic pain (NP) and also its clinical correlation to daily clinical practice. Methods: We included 1357 patients with diabetes (56.5% women, 90.4% type 2 diabetes) who were followed up in our diabetes outpatient clinic. Presence of NP was evaluated by performing simultaneous DN4 questionnaires and physical examination. Those who had a DN4 score >= 4 were considered to have NP. Results: The mean age was 58.2 +/- 12.1 years, mean duration was 12.5 +/- 7.5; (min-max: 1-45) years, mean HbA(1)c level was 7.8 +/- 1.6% (min-max: 5-16.2%), (61.7 +/- 6.0 mmol/mol; min-max: 31.1-153.6 mmol/mol). Three hundred thirteen patients (23%) were diagnosed with NP using the DN4 tool. Male gender (p = 0.01), receiving antihypertensive treatment (p = 0.01), presence of retinopathy (p < 0.001), cardiovascular disease (CVD) (p = 0.01) and previously diagnosed neuropathy (p < 0.001) were significantly associated with higher NP scores. Those who had increased DN4 scores were more likely to be on oral hypoglycemic agents (OHA) + insulin combinations (p < 0.001), had longer diabetes duration (p < 0.001) and higher HbA(1)c levels (p = 0.001). Logistic regression model revealed that diabetes duration (OR: 1.02, 95% CI: 1.00-1.04, p=0.007), elevated HbA(1)c levels (1.11, 1.02-1.21, 0.015), presence of retinopathy (1.41, 1.20-1.64, <0.001), management with at least one OHA (1.47; 1.12-1.92; 0.004) or any insulin regimen (1.62; 1.16-2.27; 0.005) (compared with diet only-regimens) were significantly associated with NP. Conclusion: Utilization of DN4 questionnaire in daily clinical practice is an effective tool in the identification of pain related with peripheral diabetic polyneuropathy. (C) 2015 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.