Objective
We investigated associations between gastrointestinal symptoms - evaluated as a combined weighted symptom score (CWSS) – Diabetic autonomic neuropathy (DAN), and distal symmetrical polyneuropathy (DSPN) in type 1 and type 2 diabetes.

Research design and methods
Cross-sectional study in a tertiary outpatient clinic. CWSS was calculated based on questionnaires: gastroparesis composite symptom index (GCSI) and gastrointestinal symptom rating score (GSRS). DAN and DSPN were addressed using the composite autonomic symptom score 31 (COMPASS-31) questionnaire, cardiac autonomic reflex tests (CARTs), electrochemical skin conductance (ESC), vibration perception threshold (VPT), Michigan Neuropathy Screening Instrument (MNSI), pain- and thermal sensation.

Analyses were adjusted for age, sex, diabetes duration, smoking, LDL-cholesterol, HbA1C and systolic blood pressure. Type 1 and type 2 diabetes were evaluated separately.

Results
We included 566 with type 1 diabetes and 377 with type 2 diabetes. Mean ± SD age was 58 ± 15 years and 565 (59.9 %) were women. A high CWSS was present in 143 (25 %) with type 1 and 142 (38 %) with type 2 diabetes. The odds of DAN by COMPASS-31 (p < 0.001) were higher in the high score group. For type 1 diabetes, odds of cardiac autonomic neuropathy were higher in the high CWSS group. The odds of DSPN by VPT and MNSI in type 1 diabetes, and by ESC, VPT and pain sensation in type 2 diabetes were higher in the high CWSS group.

Conclusions
A high symptom score was associated with neuropathy by COMPASS-31 and vibration perception. Gastrointestinal symptom burden associated inconsistently with other neuropathy tests between diabetes types.