Contemporary prevalence of diabetic neuropathies in individuals with type 1 and type 2 diabetes in a Danish tertiary outpatient clinic

Background: Population-based prevalence estimates of distal symmetric polyneuropathy (DPN) and diabetic autonomic neuropathy (DAN) are scares. Here we present neuropathy estimates and describe their overlap in a large cohort of people with type 1 and type 2 diabetes. Methods: In a large population of outpatient participants, DPN was assessed using vibration perception threshold, sural nerve function, touch, pain and thermal sensation. Definite DPN was defined by the Toronto Consensus Criteria. Painful DPN was defined by Douleur Neuropathique 4 Questions. DAN measures were: cardiovascular reflex tests, electrochemical skin conductance, and gastroparesis cardinal symptom index. Results: We included 822 individuals with type 1 (mean age (+/- SD) 54 +/- 16 years, median [IQR] diabetes duration 26 [15-40] years) and 899 with type 2 diabetes (mean age 67 +/- 11 years, median diabetes duration 16 [11-22] years). Definite DPN was prevalent in 54 % and 68 %, and painful DPN was in 5 % and 15 % of type 1 and type 2 participants, respectively. The prevalence of DAN varied between 6 and 39 % for type 1 and 9-49 % for type 2 diabetes. DPN without other neuropathy was present in 45 % with T1D and 50 % with T2D. Conclusion: The prevalence of DPN and DAN was high. DPN and DAN co-existed in only 50 % of cases.