Prevalence of Cardiac Autonomic Neuropathy (CAN) in Patients with Type 2 Diabetes Mellitus — the Interest of Studying Cardiovascular Autonomic Tests

Abstract

Objective: The objective of this study was to investigate the prevalence of cardiac autonomic neuropathy (CAN) in patients with type 2 diabetes mellitus (T2DM) using the Ewing’s autonomic cardiovascular reactivity tests and to determine the independent predictor factors of CAN in this population. Material and methods: This prospective study was conducted on 132 patients with T2DM. CAN is defined as abnormalities associated with HR control and vascular dynamics CAN is suspected in cases of persistent supine tachycardia (ST) and orthostatic hypotension (OH). Ewing’s autonomic cardiovascular reactivity tests: deep breathing, hand-grip, mental stress and orthostatic tests were performed in all patients. Statistical analysis was done using the Student's t-test, and univariate and multivariate logistic regression analysis. Results: The mean duration of diabetes was 76.4±8.3 months. Among the 132 patients with T2DM, 109 developed CAN, accounting for 82.6%. Of these, 25 patients (26.6%) had early CAN, while 84 patients (76.6%) had CAN for at least one year. In diabetic patients with CAN, the vagal response measured by the deep breathing test (XDB) was 12.1±7.3 %, the vagal response in primo-orthostatism (Xprimo-ortho) was 8.1±2.4% and the alpha peripheral adrenergic sympathetic response measured by the orthostatic test (αPAS) and the beta peripheral adrenergic sympathetic response on orthostatic test (βSP) were of, respectively 7.5±1.4%, respectively. The odds of CAN increased with duration of diabetes (p=0.003), gastroparesis (p=0.01), ischemic heart disease (p=0.006), supine hypertension (p=0.02), vagal response on the DB (p=0.001), alpha peripheral adrenergic sympathetic response (p=0.001), and beta peripheral adrenergic sympathetic response on the OT (p=0.001). Conclusion: A high frequency of CAN in patients with T2DM was significantly related with an impairment of the parasympathetic, alpha peripheral adrenergic sympathetic nervous system but other independent predictor factors were associated to the occurrence of this CAN, such as duration of diabetes, gastroparesis, ischemic heart disease and supine hypertension.