This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Takahashi, N. Articles by Sakata, T. Search for Related Content PubMed PubMed Citation Articles by Takahashi, N. Articles by Sakata, T.

CLINICAL STUDY

Effect of essential hypertension on cardiac autonomic function in type 2 diabetic patients

Naohiko Takahashi, MD^*, Mikiko Nakagawa, MD, Tetsunori Saikawa, MD, Tatsuhiko Ooie, MD^*, Kunio Yufu, MD^*, Sakuji Shigematsu, MD^*, Masahide Hara, MD^*, Hiroshi Sakino, MD^*, Isao Katsuragi, MD^*, Toshimitsu Okeda, MD^*, Hironobu Yoshimatsu, MD^* and Toshiie Sakata, MD^*

^* Department of Internal Medicine I, School of Medicine, Oita Medical University, Oita, Japan
Department of Laboratory Medicine, School of Medicine, Oita Medical University, Oita, Japan

Manuscript received December 1, 2001; revised manuscript received March 21, 2001, accepted April 5, 2001.

Reprint requests and correspondence: Dr. Naohiko Takahashi, Department of Internal Medicine I, School of Medicine, Oita Medical University, 1-1 Idaigaoka, Hasama, Oita 879-5593, Japan
takanao{at}oita-med.ac.jp

OBJECTIVES

The aim of this study was to examine the effects of essential hypertension on cardiac autonomic function in type 2 diabetic patients.

BACKGROUND

Hypertension is common in type 2 diabetic patients and is associated with a high mortality. However, the combined effects of type 2 diabetes and essential hypertension on cardiac autonomic function have not been fully elucidated.

METHODS

Thirty-three patients with type 2 diabetes were assigned to a hypertensive diabetic group (n = 15; age: 56 ± 8 years, mean ± SD) or an age-matched normotensive diabetic group (n = 18, 56 ± 6 years). Cardiac autonomic function was assessed by baroreflex sensitivity (BRS), heart rate variability (HRV), plasma norepinephrine concentration and cardiac ¹²³I-metaiodobenzylguanidine (MIBG) scintigraphic findings.

RESULTS

Baroreflex sensitivity was lower in the hypertensive diabetic group than it was in the normotensive diabetic group (p < 0.05). The early and delayed myocardial uptake of ¹²³I-MIBG was lower (p < 0.01 and p < 0.05, respectively), and the percent washout rate of ¹²³I-MIBG was higher (p < 0.05) in the hypertensive diabetic group. However, the high frequency (HF) power and the ratio of low frequency (LF) power to HF power (LF/HF) of HRV and plasma norepinephrine concentration were not significantly different. The homeostasis model assessment index was higher in the hypertensive diabetic group than it was in the normotensive diabetic group (p < 0.01).

CONCLUSIONS

Our results indicate that essential hypertension acts synergistically with type 2 diabetes to depress cardiac reflex vagal and sympathetic function, and the results also suggest that insulin resistance may play a pathogenic role in these processes.

Abbreviations and Acronyms   BRS = baroreflex sensitivity   ECG = electrocardiogram   H/M = heart-to-mediastinum   HF = high frequency component (0.15 to 0.45 Hz)   HOMA = homeostasis model assessment   HRV = heart rate variability   LF = low frequency component (0.04 to 0.15 Hz)   LV = left ventricular   MIBG = metaiodobenzylguanidine   NE = norepinephrine   WR = washout rate

This article has been cited by other articles:

				Z. Y. Fang, J. B. Prins, and T. H. Marwick Diabetic Cardiomyopathy: Evidence, Mechanisms, and Therapeutic Implications Endocr. Rev., August 1, 2004; 25(4): 543 - 567. [Abstract] [Full Text] [PDF]

				R. J. Huggett, E. M. Scott, S. G. Gilbey, J. B. Stoker, A. F. Mackintosh, and D. A.S.G. Mary Impact of Type 2 Diabetes Mellitus on Sympathetic Neural Mechanisms in Hypertension Circulation, December 23, 2003; 108(25): 3097 - 3101. [Abstract] [Full Text] [PDF]

				J. Davies and A. Struthers Review: The potential benefits of aldosterone antagonism in Type 2 diabetes mellitus Journal of Renin-Angiotensin-Aldosterone System, September 1, 2002; 3(3): 150 - 155. [Abstract] [PDF]