Heart rate variability is severely impaired among type 2 diabetic patients with hypertension

• Published in: Diabetes/metabolism research and reviews Vol. 30; no. 4; pp. 305 - 312
• Main Authors: Istenes, Ildikó, Körei, Anna Erzsébet, Putz, Zsuzsanna, Németh, Nóra, Martos, Timea, Keresztes, Katalin, Kempler, Miklós Soma, Erzsébet, Vági Orsolya, Vargha, Péter, Kempler, Péter
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01-05-2014; Wiley Subscription Services, Inc
• Subjects: Autonomic Nervous System Diseases - complications; Autonomic Nervous System Diseases - epidemiology; Autonomic Pathways - physiopathology; Blood Pressure; cardiovascular autonomic neuropathy; Cross-Sectional Studies; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - physiopathology; Diabetic Angiopathies - complications; Diabetic Angiopathies - physiopathology; Diabetic Cardiomyopathies - complications; Diabetic Cardiomyopathies - epidemiology; Diabetic Neuropathies - complications; Diabetic Neuropathies - epidemiology; Female; Heart Rate; heart rate variability; Heart Ventricles - innervation; Heart Ventricles - physiopathology; Humans; Hungary - epidemiology; Hypertension - complications; Hypertension - physiopathology; Male; Middle Aged; Monitoring, Ambulatory; Reproducibility of Results; Risk; type 2 diabetes; Ventricular Dysfunction - complications; Ventricular Dysfunction - epidemiology; Hungary
• ISSN: 1520-7552; 1520-7560
• DOI: 10.1002/dmrr.2496

Introduction
The aim of our study was to evaluate the relative effect of diabetes and hypertension on heart rate variability.
Research design and methods
Four age‐matched groups including type 2 diabetic patients with and without hypertension, non‐diabetic patients with essential hypertension and healthy control subjects were studied. Autonomic function was evaluated by the standard cardiovascular reflex tests and 24‐hour heart rate variability measurement. Heart rate variability was characterized by the triangular index value and by the spectral components of the frequency domain analysis.
Results
According to the two‐way analysis of variance on ranks, all parameters were influenced negatively by diabetes (heart rate variability triangular index: p < 0.001; low‐frequency component: p < 0.0001; high‐frequency component: p < 0.001; and total power: p < 0.0001), whereas hypertension had a negative effect only on the low‐frequency component (p < 0.05). The interaction between hypertension and diabetes was not significant, indicating that their effects on the heart rate variability parameters are additive. Beat‐to‐beat variation upon deep breathing, the most sensitive cardiovascular reflex test was also negatively influenced by both diabetes (p < 0.001) and hypertension, (p < 0.05), and their effects were additive.
Conclusions
Diabetes appears to have a greater effect on autonomic dysfunction compared with hypertension. Patients suffering from both diabetes and hypertension are at the highest risk of reduced heart rate variability. Early assessment of the autonomic nerve function is suggested in diabetic patients with hypertension. Copyright © 2013 John Wiley & Sons, Ltd.