title: Decreased heart rate variability may predict the progression of carotid atherosclerosis in type 2 diabetes.
abstract: Heart rate variability (HRV), a measure of autonomic function, can predict survival outcomes. Cardiovascular disease is a known complication of diabetes, and we aimed to determine if autonomic dysfunction was associated with carotid artery atherosclerotic plaques in type 2 diabetic patients. We assessed frequency domain HRV from power spectral analysis of 24 h Holter ECG recordings, expiration/inspiration (E/I) ratio during deep breathing, acceleration index (AI) of R-R interval in response to head-up tilt, and the degree of carotid artery atherosclerosis in 61 type-2 diabetic patients (39 males, 45-69 years). Studies were carried out 5-6 years after diagnosis (baseline) and repeated 8 years after diagnosis (follow-up). At baseline, patients diagnosed with autonomic neuropathy, with abnormal E/I ratio and abnormal AI measurements, had decreased low frequency (LF) HRV. Baseline E/I ratio correlated with day (r = 0.34; P < 0.001) and night-time (r = 0.44; P < 0.001) LF power. Night-time HRV did not differ in patient with and without autonomic neuropathy. Reduced common carotid artery diameter and atherosclerotic intima-media thickness (IMT) both correlated with HRV at baseline. At follow-up, all HRV variables decreased significantly. Furthermore, patients with lower LF power at baseline, had a larger increase in the thickness of the carotid bulb intima-media at follow-up. Our results show that LF HRV power is associated with the extent and progression of carotid atherosclerosis in type 2 diabetes. A low LF HRV may predict the progression of atherosclerosis in these patients.
authors.affiliation: Dept. of Vascular Diseases, University of Lund, University Hospital UMAS, S-205 02, Malmö, Sweden. anders.gottsater@skane.se
authors.forename: Anders
authors.initials: A
authors.lastname: Gottsäter
authors.forename: Asa Rydén
authors.initials: AR
authors.lastname: Ahlgren
authors.forename: Soumia
authors.initials: S
authors.lastname: Taimour
authors.forename: Göran
authors.initials: G
authors.lastname: Sundkvist
mesh_terms: D000368:Aged; D002340:Carotid Artery Diseases / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003929:Diabetic Neuropathies / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D018450:Disease Progression; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006334:Heart Function Tests; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D018667:Tilt-Table Test