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

• Twenty three percent of the study group was diagnosed as NP using the DN4 tool.
• Diabetes duration, high HbA1c levels, presence of retinopathy were related with NP.
• DN4 questionnaire is easy and effective to evaluate NP.
• In order to evaluate these patients for diabetic neuropathy use of both DN4 and foot examination is valuable.

AimWe 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.MethodsWe 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.ResultsThe mean age was 58.2 ± 12.1 years, mean duration was 12.5 ± 7.5; (min–max: 1–45) years, mean HbA1c 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 HbA1c levels (p = 0.001). Logistic regression model revealed that diabetes duration (OR: 1.02, 95% CI: 1.00–1.04, p = 0.007), elevated HbA1c 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.ConclusionUtilization of DN4 questionnaire in daily clinical practice is an effective tool in the identification of pain related with peripheral diabetic polyneuropathy.