Prevalence of painful and painless diabetic peripheral neuropathy in the Northern Danish Region: A population-based study.

Background: Diabetic peripheral neuropathy (DPN) is a common complication of diabetes, yet varying estimates of its prevalence exist. The present study aimed to estimate a questionnaire-centered prevalence of painful and painless DPN in the Northern Danish Region, examine its geographical distribution within the region, and investigate associations between DPN and potential risk factors.

Methods: A questionnaire-based survey was sent to all persons living with diabetes in the Northern Danish Region using electronic mail. Persons with diabetes were identified using The National Health Insurance Service Registry. The survey included information on demographics, socioeconomics, municipality, diabetes type, duration, and treatment, as well as the validated questionnaires Michigan Neuropathy Screening Instrument-questionnaire (MNSIq) and the Douleur Neuropathique en 4 Questions (DN4)-interview. Possible DPN was defined as an MNSIq-score ≥ 4, while possible painful DPN was defined as pain in both feet and a DN4-interview score ≥ 3.

Results: A total of 23,206 eligible people were identified as having diabetes and approximately 33 % answered all questionnaires. The prevalence of possible DPN was 23.3 % (95 % CI: 22.4-24.3 %), while the prevalence of possible painful DPN was 18.0 % (17.1-18.8 %). The prevalence of possible DPN ranged from 22.1 % to 35.0 % between municipalities, while the prevalence of possible painful DPN ranged from 15.6 % to 20.0 %. High body-mass index, long diabetes duration, insulin use, glucagon-like-peptide-1-analogue use, and low income were associated with increased risk of DPN.

Conclusion: The high prevalence of possible painless and painful DPN emphasizes the need for better prevention and careful screening even in high-income countries.