Exp Clin Endocrinol Diabetes 2006; 114(4): 153-159
DOI: 10.1055/s-2006-924083
Article

J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart · New York

Selective Contribution of Diabetes and Other Cardiovascular Risk Factors to Cardiac Autonomic Dysfunction in the General Population

D. Ziegler1 , C. Zentai1 , S. Perz2 , W. Rathmann3 , B. Haastert3 , C. Meisinger4 , H. Löwel4 , for the KORA Study Group
  • 1German Diabetes Clinic, German Diabetes Center, Leibniz Institute at the Heinrich Heine University, WHO Collaborating Center in Diabetes, European Training Center in Endocrinology and Metabolism, Düsseldorf, Germany
  • 2Institute of Medical Informatics, GSF - Research Center of Environment and Health, Neuherberg, Germany
  • 3Institute of Biometrics and Epidemiology, German Diabetes Center, Leibniz Institute at the Heinrich Heine University, WHO Collaborating Center in Diabetes, European Training Center in Endocrinology and Metabolism, Düsseldorf, Germany
  • 4Institute of Epidemiology, GSF - Research Center of Environment and Health, Neuherberg, Germany
Further Information

Publication History

Received: December 30, 2005 First decision: February 14, 2006

Accepted: February 20, 2006

Publication Date:
18 May 2006 (online)

Introduction

Risk factors for cardiovascular disease (CVD), including several components of the metabolic syndrome, represent a major cause of premature death ([Adult Treatment Panel III, 2002]; [Grundy et al., 2004]; [Malik et al., 2004]). The worldwide dramatic increase of obesity and diabetes causes an enormous burden to the persons affected, public health, and to national health budgets. The autonomic nervous system (ANS) plays a paramount role in affecting the cardiac milieu and promoting malignant ventricular activity ([Villareal et al., 2002]). Heart rate variability (HRV) is a noninvasive tool for assessing the status of the ANS in various diseases. Reduced HRV has been shown to predict increased mortality in the general population ([Dekker et al., 1997]) and in patients with CVD ([Villareal et al., 2002]). In diabetic patients, reduced HRV is regarded as a hallmark of cardiac autonomic neuropathy (CAN) which represents a serious complication ([Ziegler, 1999]) associated with an approximately 2-fold increased mortality ([Vinik et al., 2003]; [Maser et al., 2003]), sudden death ([Suarez et al., 2005]), and silent myocardial ischemia ([Vinik et al., 2003]; [Wackers et al., 2004]). Accumulating evidence suggests that reduced HRV may predict the development of CVD ([Valensi et al., 2001]) and stroke ([Toyry et al., 1996]).

The QT interval represents the period of global ventricular depolarization and subsequent repolarization. Prolongation of the QT interval corrected for heart rate (QTc) has been associated with an increased incidence of ventricular arrhythmias ([Chen and Kusumoto, 2004]). The QT dispersion (QTD), which has been defined as the difference between the longest and shortest QT intervals on a standard 12-lead ECG, is considered to reflect regional variation in ventricular recovery times. This spatial dispersion of repolarization could offer an electrophysiological substrate for malignant ventricular arrhythmias ([Chen and Kusumoto, 2004]; [Manttari et al., 1997]). Both prolonged QTc interval and increased QTD have been identified as predictors of increased cardiovascular and all-cause mortality in the general population ([Manttari et al., 1997]; [de Bruyne et al., 1998]; [de Bruyne et al., 1999]; [Karjalainen et al., 1997]) and in the diabetic population ([Okin et al., 2004]).

The significance of HRV, QTc, and QTD in the context of cardiovascular risk factors has not been addressed systematically in previous studies ([Whitsel et al., 2000]; [Festa et al., 2000]; [Brown et al., 2001]; [Carnethon et al., 2002]). Because reduced HRV, prolonged QTc, and increased QTD contribute to increased mortality, these risk markers were measured in the population-based MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) Augsburg survey 1989/90 (S2), Germany, to elucidate to which extent such cardiac autonomic abnormalities are determined by major cardiovascular risk factors.

References

MD, FRCPE Dan Ziegler

Deutsche Diabetes-Klinik
Deutsches Diabetes-Zentrum
Leibniz-Zentrum an der Heinrich-Heine-Universität

Auf'm Hennekamp 65

40225 Düsseldorf

Germany

Phone: + 4921133821

Fax: + 49 21 13 38 22 77

Email: dan.ziegler@ddz.uni-duesseldorf.de