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[Autonomic neuropathy in diabetics--autonomic function and plasma catecholamines]
N Kikuchi1, M Nanno, H Kurahachi
1Department of Internal Medicine, Hamamatsu University School of Medicine, Japan.
Nihon Naibunpi Gakkai Zasshi
|February 20, 1988
Summary
Diabetic autonomic neuropathy impairs sympathetic function, evidenced by reduced norepinephrine and epinephrine responses to stimuli like standing and smoking. Parasympathetic function, measured by R-R interval variation, correlates with sympathetic deficits in diabetic patients.
Area of Science:
- Endocrinology and Metabolism
- Cardiovascular Physiology
- Neuroscience
Context:
- Diabetic autonomic neuropathy is a significant complication affecting cardiovascular regulation.
- While parasympathetic function is often assessed via R-R interval variation, quantitative evaluation of sympathetic function in diabetics remains less explored.
- Previous studies highlight R-R interval variation as a noninvasive measure of parasympathetic activity.
Purpose:
- To quantitatively evaluate sympathetic nervous system function in diabetic patients with varying degrees of neuropathy.
- To compare sympathetic responses with parasympathetic function (R-R interval variation) across different diabetic groups.
- To investigate the impact of autonomic symptoms and complications on sympathetic and parasympathetic responses.
Summary:
- Diabetic patients, particularly those with autonomic symptoms (Group IV) and peripheral neuropathy (Group III), exhibited significantly reduced plasma norepinephrine (NE) and epinephrine (E) responses to postural changes (standing) and sympathetic stimuli (handgrip, smoking) compared to normal subjects (Group I) and diabetics without complications (Group II).
- Blood pressure drop upon standing was observed only in Group IV. Heart rate responses to standing and smoking were blunted in Groups III and IV.
- R-R interval variation (CV), a measure of parasympathetic function, was significantly lower in Groups III and IV and strongly correlated with NE and E responses to standing and smoking, indicating a link between impaired sympathetic and parasympathetic function.
Impact:
- This study provides quantitative evidence of sympathetic dysfunction in diabetic autonomic neuropathy, extending beyond parasympathetic assessment.
- The findings underscore the clinical relevance of assessing both sympathetic and parasympathetic functions for a comprehensive understanding of diabetic autonomic neuropathy.
- The strong correlation between parasympathetic and sympathetic function markers suggests a systemic autonomic impairment in advanced diabetic neuropathy.