Orthostatic Hypotension and Heart Rate Variability as Signs of Cardiac Autonomic Neuropathy in Diabetes Mellitus

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Anahtar Kelimeler

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Orthostatic Hypotension and Heart Rate Variability as Signs of Cardiac Autonomic Neuropathy in Diabetes Mellitus

Öz

Aim: The aim of this study was to emphasize two different points in our work: 1) The well known importance of (subclinical) postural hypotension and reduced heart rate variability as (early) markers of autonomic neuropathy; 2) and the more controversial influence of diabetic control in their worsening. Methods: Two standard cardiovascular response tests (heart rate variability by respiration and orthostatic blood pressure changes) were carried out on 93 diabetic patients with prolonged QT interval in order to determine cardiac dysautonomy. QT segment duration was measured on electrocardiography recordings. Patients with HbA1c levels below 7 were considered as wellcontrolled diabetics. A cut off of 5 years was selected for the known duration of diabetes. The relations between cardiac autonomic neuropathy and diabetic control and the known duration of diabetes were determined. Results: The mean values for the known duration of diabetes and HbA1c level were 10±7.23 years and 9.5±2.3 mg/dl respectively. Median QTc differences, postural change in the systolic blood pressure, and changes of heart rate by respiration were 0.62 sec, 20 mmHg, and 6 beat/min, respectively. There was no difference in QTc values with respect to diabetes control but QTc values were significantly different with regard to the known duration of diabetes. Blood pressure variations with standing were significantly related to control as well as the known duration of diabetes. Variability of hearth rate with respiration on the other hand was significantly related to the duration but not to the control of diabetes. QTc showed a significant correlation with the known duration of diabetes, postural blood pressure changes, and heart rate variability with respiration. Conclusion: Clinician\'s should be more alert for the signs of autonomic neuropathy, especially in patients with a history of diabetes for more than five years. Special attention should be given to postural blood pressure changes and heart rate variability with respiration. Key words: Diabetes, autonomic neuropathy, HbA1c, QT interval, heart rate variability, orthostatic hypotension

Anahtar Kelimeler

• Diabetes, autonomic neuropathy, HbA1c, QT interval, heart rate variability, orthostatic hypotension

Kaynakça

1. Rathmann W, Ziegler D, Jahnke M, Haastert B, Gries FA. Mortality in diabetic patients with cardiovascular autonomic neuropathy. Diabet Med 1993;10(9):820
2. Schwartz PJ, Priori SG. Sympathetic nervous system and cardiac arrhytmias. In: Zipes DP, Jalife I, eds. Cardiac Electrophysiology. From cell to bedside. Philadelphia: W.B. Saunders 1990:330
3. Oka H, Mochio S, Sato K et al. Prolongation of QTc interval and nervous dysfunction in diabetic patients. Diabetes Res Clin Pract 1996;31(1-3):63-70
4. Kumhar MR, Agarval TD, Singh VB, Kochar DK, Chadda VS. Cardiac autonomic neuropathy and its correlation with QTc dispersion in type 2 diabetes. Indian Heart J 2000;52(4):421-6
5. Lo ss, Sutton MS, Leslie RD. Information on type I diabetes mellitus and QT interval from identical twins. Am J Cardiol 1993;72(3):305-9
6. Jermendy G, Toth L, Voros P, Koltai MZ, Pogatsa G. Cardiac autonomic neuropathy and QT interval length. A follow-up study in diabetic patients. Acta Cardiol 1991;46(2):189-200
7. Katsuoka H, Mimori Y, Kurokawa K et al. QTc interval, and autonomic and somatic nerve function in diabetic neuropathy. Clin Auton Res 1998;8(3):139-43
8. Task Force of the European Society of Cardiology and the North American Society of pacing and Electrophysiology: Heart rate variability-standars of measurement, physiological interpretation, and clinical use. European Heart Journal 1996;17: 354-81

9. Aytemir K, Aksoyek S, Özeer N, Gürlek A, Oto A. QT dispersion and autonomic nervous system function in patients with type I diabetes. Int J Cardiol 1998;65(1): 45-50
10. Rossing P, Breum L, Major-Pedersen A, Sato A, Winding H, Pietersen A, Kastrup J, Parving HH. Prolonged QTc interval predicts mortality in patients with Type I diabetes mellitus. Diabet Med 2001;18(3): 199-205
11. Veglio M, Sivieri R, Chinaglia A, Scaglione L, Cavallo-Perin P. QT interval prolongation and mortality in type 1 diabetic patient: a 5-year cohort prospective study. Neuropathy Study Group of the Italian Society of the Study of Diabetes, Piemonte Affiliate. Diabetes Care 2000;23(9):1381-3
12. Veglio M, Chinaglia A, Borra M, Perin PC. Does abnormal QT interval prolongation reflect autonomic dysfunction in diabetic patients QTc interval measure versus standardized tests in diabetic autonomic neuropathy. Diyabet Med 1995;12(4): 302-6
13. Tentolouris N, Katsilambros N, Papzachos G et al. Corrected QT interval in relation to the severity of diabetic autonomic neuropathy. Eur J Clin Invest 1997;27(12): 1049-54
14. Bloom A, Ireland J, Watkins P. Autonomic Neuropathy. Nervous System. In: A colour atlas of diabetes. Wolfe Publishing Ltd. Second Edition. Spain 1992:98 15. Purewal TS, Watkins PJ.Postural hypotension in diabetic autonomic neuropathy a review. Diabet Med 1995;12(3):192-200