Key result
Diabetic autonomic neuropathy is linked to an abnormal 30:15 R-R standing ratio below ~1.03.
Why the study?
Does the immediate heart-rate response to standing (30:15 R-R interval ratio) accurately identify autonomic neuropathy in diabetic patients?
Cross-Sectional (n=47)
No
Does the immediate heart-rate response to standing (30:15 R-R interval ratio) accurately identify autonomic neuropathy in diabetic patients?
The 30:15 R-R interval ratio upon standing is a simple, non-invasive outpatient test that effectively differentiates diabetic patients with autonomic neuropathy from those with intact autonomic function.
Supports 30:15 ratio as simple bedside screen for diabetic autonomic neuropathy; leaves open prospective validation in larger cohorts.
The immediate heart-rate response to standing was measured in 22 normal controls and 25 patients with diabetes, 15 of whom had autonomic neuropathy. The response in the controls and patients without autonomic neuropathy was characteristic and consistent, with tachycardia maximal at around the 15th beat and relative bradycardia maximal at around the 30th beat. The diabetics with autonomic neuropathy, however, showed a flat response. In three controls the response was abolished with intravenous atropine but not with propranolol, showing that it is mediated through the vagus. A simplified test using routine ECGs and measuring the R-R interval at beats 15 and 30 with a ruler is easily performed as an outpatient procedure and may be used as a measure of autonomic function in diabetes.
No takes yet. Share an insight, caveat, or question.
Ewing et al. (1978) conducted a cross-sectional in Diabetic autonomic neuropathy (n=47). Diabetic autonomic neuropathy vs. Healthy controls and diabetics without autonomic neuropathy was evaluated on 30:15 R-R interval ratio upon standing. All 15 diabetic patients with autonomic neuropathy showed a flat heart-rate response to standing with a 30:15 R-R ratio <1.03, whereas all but one control and all diabetics without neuropathy had a normal response with a ratio ≥1.03.
Synapse has enriched 5 related papers. Consider them for comparative context: