Comparison of Ewing test and heart rate variability for cardiovascular autonomic neuropathy in patients with newly diagnosed type 2 diabetes mellitus

Abstract

Objective To assess the positive rate and characteristics of cardiovascular autonomic neuropathy (CAN) in patients with newly diagnosed type 2 diabetes and to compare Ewing test with heart rate variability (HRV) for identifying CAN. Methods Ninety newly diagnosed type 2 diabetic patients (diabetic group) and 40 healthy subjects (control group) were enrolled from Department of Endocrinology and Metabolism of 4 hospitals in Guangdong Province(the Third Affiliated Hospital of Sun Yat-sen University, the First Affiliated Hospital of Shantou University Medical College, Guangdong General Hospital, Zhujiang Hospital of Southern Medical University). The diabetic group included 58 males and 32 females, with an average age (47±1) years. The control group included 21 males and 19 females, with an average age (45±2) years. Standard Ewing test and Holter (HRV analysis) were used to evaluate CAN, and comparison of these two diagnostic methods was committed. Difference of measurement data was compared with t test or one-way ANOVA and rank sum test was used for ranked data. Results (1) The results of Ewing test showed that the positive rate of CAN in newly diagnosed type 2 diabetic patients (22.2% (20/90)) was higher than that in the controls (7.5% (3/40), χ2=4.12, P 0.05). Conclusions Both Ewing tests and HRV showed a higher positive rate of CAN in the newly diagnosed type 2 diabetic patients than that in the control group, and parasympathetic function was mainly damaged. More CAN patients were detected by HRV than by Ewing test. Key words: Diabetes mellitus, type 2; Cardiovascular autonomic neuropathy; Ewing test; Heart rate variability