Autonomic Neuropathy—a Prospective Cohort Study of Symptoms and E/I Ratio in Normal Glucose Tolerance, Impaired Glucose Tolerance, and Type 2 Diabetes

Abstract

BackgroundAutonomic neuropathy in diabetes, in addition to causing a range of symptoms originating from the autonomic nervous system, may increase cardiovascular morbidity. Our aim was to study the progression of autonomic neuropathy, based on symptom score and evaluation of an autonomic test, in persons with normal and impaired glucose tolerance and in patients with type 2 diabetes (T2D).MethodsParticipants were recruited in 2003/2004 with a follow-up in 2014. The participants’ glucose tolerance was categorized using oral glucose tolerance tests. Symptoms were evaluated using an autonomic symptom score (ASS), ECG was used to test cardiac autonomic function based on the expiration/inspiration ratio (E/I ratio), and blood samples were taken on both occasions.ResultsASSs were higher at follow-up in the T2D patients than in the normal glucose tolerance group (mean 1.21 ± 1.30 vs. 0.79 ± 0.7; p < 0.05). E/I ratio did not deteriorate more than could be expected as an aging effect in well-controlled T2D. No relationship was found between E/I ratio and HbA1c or ASS.ConclusionThe presence of autonomic symptoms increased over time in T2D patients, but the symptoms did not correlate with the E/I ratio in this metabolically well-controlled cohort. ASSs can be a useful clinical tool when assessing the progression of autonomic dysfunction in patients with abnormal glucose metabolism.

Autonomic and peripheral neuropathy with reduced intraepidermal nerve fiber density can be observed in patients with gastrointestinal dysmotility

“…A questionnaire concerning the symptoms usually present in patients with gastric paresis and/or GI dysmotility, the validated Autonomic Symptom Score, and the validated Neuropathy Symptom Score were completed by the patients.…”

“… 0 = never, 1 = sometimes, 2 = often, + = presence of symptoms without determination of degree of symptoms. Questionnaires of gastric paresis/gastrointestinal dysmotility and autonomic symptom score …”

The prevalence of cardiac autonomic neuropathy in prediabetes: a systematic review

“…Summary of studies The majority of studies were carried out in European populations (n = 7) [25,[36][37][38][39][40][41]; other locations were China (n = 1) [42], Brazil (n = 1) [43], USA (n = 1) [44] and Australia (n = 1) [45]. The studies sample sizes ranged from 52 to 1638 participants [25,[36][37][38][39][40][41][42][43][44][45][46][47]. All studies included tests of cardiac autonomic function.…”

“…Study design and participants Eight studies were cross sectional [25,36,37,39,[41][42][43][44], two were cohort studies [38,40] and one was a prospective observational study [45]. CAN prevalence data were presented for a total of 1730 participants with prediabetes, 1999 participants with NGT and 702 participants with predominantly type 2 diabetes.…”

“…CAN prevalence data were presented for a total of 1730 participants with prediabetes, 1999 participants with NGT and 702 participants with predominantly type 2 diabetes. The mean age of participants in the studies varied from 39 years to 65 years [25,[36][37][38][39][40][41][42][43][44][45]. In general, there was similar recruitment of participants based on sex.…”