Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCB010

Poster Communications

To evaluate the diagnostic efficacy of parasympathetic autonomic response latency in type 2 diabetes mellitus

R. Sharma1, S. Ravichandran1, P. H. Kamble1, A. Singhal1, Y. Singh2,1

1. Physiology, All India Institute of Medical Sciences, Jodhpur, Jodhpur, Rajasthan, India. 2. Physiology, RKGMC, Hamirpur, India.

Introduction: The clinical complications of diabetes induced cardiac autonomic neuropathy (CAN) include resting tachycardia, orthostatic hypotension, exercise intolerance and myocardial infarction with increased risk of mortality. To identify early stages of CAN tests heart rate variability (HRV) and autonomic reactivity based on Ewing score are helpful. Latency parameters are routinely used in most of the usual evoked potential studies. It has been found to have diagnostic and prognostic value for many disorders. Sharma et al in 2004 had identified this parameter in cardiovascular autonomic reactivity testing and addressed it in normal healthy young adults who underwent a short term physical training. Thus latency, i.e. time taken by the system to manifest peak change in the cardiovascular response to various stimuli which perturb the hemodynamic status should also be measured and quantified. This would provide an additional dimension to the already routinely quantifiable cardiovascular autonomic response parameters. To the best of our knowledge, no study has been undertaken to study these parameters in diabetic patients. Methods: So the authors evaluated the diagnostic efficacy of Tachycadia and Bradycardia latencies (TL and BL) in routine parasympathetic reactivity tests which included Lying to standing and Valsalva manouevre. A total of 52 diagnosed Type 2 DM subjects were included in this study. The participants were excluded if they had any other systemic or endocrine disorder other than diabetes. The statistical analysis of the data was done by using ROC curve and its standard parameters. Results: The area under curve for tachycardia latency and bradycardia latency during lying to standing test was 0.624 and 0.632 with 95% confidence interval of 0.393-0.441 and 0.441-0.824 respectively. Similarly, the area under curve for tachycardia latency and bradycardia latency during Valsalva maneuver was 0.499 and 0.590 with 95% confidence interval of 0.288-0.710 and 0.384-0.796 respectively. While E:I ratio, 30:15 ratio, Valsalva ratio and Delta HR during DBT had smaller area as compared to latency parameters. Conclusion: This suggests that latency parameters have better sensitivity and specificity as compared to individual parasympathetic reactivity tests.

Where applicable, experiments conform with Society ethical requirements