Changing associations between progressive cardiovascular autonomic neuropathy and carotid atherosclerosis with increasing duration of Type 2 diabetes mellitus

To clarify associations between cardiovascular autonomic neuropathy (CAN) and the progression of carotid artery atherosclerosis in Type 2 diabetic patients, cardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients, 5 and 8 years after the diagnosis of diabetes. Between 5 and 8 years after diagnosis, age-adjusted acceleration index (AI) decreased (from -0.306 +/- 1.034 to -0.702 +/- 1.072; P = .0139), whereas age-adjusted expiration/inspiration (E/I) ratio was unchanged (-0.583 +/- 1.038 and -0.828 +/- 1.028; P = .1164). Intima-media thickness (IMT) increased in both the common carotid artery (CCA; from 0.854 +/- 0.219 to 0.913 +/- 0.241 mm; P < .0001) and the carotid bulb (from 1.789 +/- 0.714 to 2.128 +/- 0.881 mm; P < .0001), corresponding to a yearly IMT increase of 0.032 +/- 0.039 turn in the CCA and 0.146 +/- 0.204 mm in the carotid bulb. This value did not correlate with the AI or E/I ratios. In age-controlled partial correlation in the first examination, AI correlated inversely with mean (r = -.33, P = .018) IMT in the CCA, but not with IMT in the carotid bulb (r = -.14, P = .303). However, in contrast to the first examination, at follow-up, AI correlated inversely with the mean IMT of the carotid bulb (r = -40, P = .007), lumen diameter of the CCA (r = -.31, P = .034), and plaque score (r = -.29, P = .041), but not with IMT of the CCA (r = -.04, P = .861). There were no correlations between the E/I ratio and carotid variables. In conclusion, CAN was associated with features of carotid atherosclerosis, which, in the carotid bulb, might affect baroreceptor function with the progression of Type 2 diabetes. (c) 2005 Elsevier Inc. All rights reserved.