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

Abstract

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 >or=15 beats/min, deep breathing expiratory to inspiratory R-R ratio >or=1.21, Valsalva ratio >or=1.21, sustained handgrip test >or=16 mm of mercury, cold pressor test >or=10, BP response to standing <or=10mm of mercury and 30:15 R-R ratio on standing >or=1.04. An abnormal test was defined as the above parameters being <10 beats/min, <1.21, <1.21, <or=10mm of mercury, <10, >or=30 mm of mercury and <or=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.