Autonomic Symptoms and Diabetic Neuropathy

TLDR

Autonomic symptoms and deficits are known to occur in diabetes, but a comprehensive symptom profile has not yet been described. The study aimed to estimate such a profile by combining laboratory autonomic testing with a validated self‑report questionnaire in diabetic patients and matched controls from the Rochester Diabetic Neuropathy Study. Researchers evaluated 231 diabetic patients and 245 healthy controls, using the Autonomic Symptom Profile questionnaire and the objective Composite Autonomic Severity Score (CASS) to assess symptom severity and autonomic deficits. Autonomic symptoms and deficits were common (54 % in type 1 and 73 % in type 2), generally mild (mean CASS 2.3), with orthostatic hypotension in about 8 % of patients, and the correlation between symptom scores and CASS was weak overall, highlighting the need for separate symptom evaluation.

Abstract

OBJECTIVE—The prevalence of autonomic symptoms and deficits in certain systems is known, but a comprehensive autonomic symptom profile in diabetes is not available. We aimed to estimate this using a laboratory evaluation of autonomic function and a validated self-report measure of autonomic symptoms in patients and matched control subjects from the population-based Rochester Diabetic Neuropathy Study. RESEARCH DESIGN AND METHODS—Participants included 231 patients with diabetes (type 1, n = 83; type 2, n = 148) and 245 healthy age-matched control subjects. We assessed symptoms using a validated self-report instrument (Autonomic Symptom Profile) and evaluated the severity and distribution of autonomic deficits (cardiovagal, sudomotor, adrenergic) with the objective, laboratory-based Composite Autonomic Severity Score (CASS). RESULTS—Autonomic symptoms were present more commonly in type 1 than in type 2 diabetes, with symptoms of orthostatic intolerance, secretomotor, urinary control, diarrhea, and sleep disturbance and pupillomotor, vasomotor, and erectile dysfunction significantly increased over healthy control subjects in type 2 diabetic patients. The prevalence of autonomic impairment was 54% in type 1 and 73% in type 2 diabetic patients. Severity of autonomic failure was mild overall (mean CASS 2.3; maximum 10), with orthostatic hypotension occurring in 8.4 and 7.4% of type 1 and 2 diabetic patients, respectively. Fourteen percent of patients had a CASS ≥5, indicating moderate to severe generalized autonomic failure. The correlation of symptoms with autonomic deficits (CASS) was better in type 1 than type 2 diabetic subjects and was weak overall. CONCLUSIONS—These findings indicate that autonomic symptoms and deficits are common in diabetes, but mild in severity, and that the correlation between symptom scores and deficits is overall weak in mild diabetic neuropathy, emphasizing the need to separately evaluate autonomic symptoms.