Prevalence and pattern of cardiac autonomic dysfunction in newly detected type 2 diabetes mellitus

Cardiac autonomic functions were assessed in 145 consecutive recently detected type 2 diabetics. Ninety-nine healthy persons served as controls. Criteria for normalcy were, heart rate variation during deep breathing >= 15 beats/min, deep breathing expiratory to inspiratory R-R ratio >= 1.21, Valsalva ratio >= 1.21, sustained handgrip test >= 16 mm of mercury, cold pressor test >= 10, BP response to standing <= 10 mm of mercury and 30:15 R-R ratio on standing >= 1.04. An abnormal test was defined as the above parameters being < 10 beats/min, < 1.21, < 1.21, <= 10mm of mercury, < 10, > 30 mm of mercury and <= 1.0, respectively. A borderline test was defined as, heart rate variation during deep breathing 11-14, sustained handgrip test 11-15 mm of mercury, BP response to standing 11-29 mm of mercury and 30:15 R-R ratio on standing 1.01-1.03. Parasympathetic dysfunction was found in 44.2% and sympathetic dysfunction in 51.9% diabetics. Among healthy controls, these figures were 11.9% and 22.1%, respectively. Cardiac autonomic function was normal in 7.8% patients and 32.5% healthy controls. (C) 2008 Elsevier Ireland Ltd. All rights reserved.