High prevalence and severity of cardiac autonomic neuropathy in Vietnamese diabetic patients

Abstract

Malnutrition is frequent in Vietnamese people and may influence cardiac autonomic neuropathy (CAN). The aim of the present study was to investigate cardiac autonomic function in healthy subjects living in Vietnam and the prevalence of CAN in Vietnamese diabetic patients. One hundred and five diabetic patients (BMI = 19.8 +/- 0.3 kg/m(2)), 50 Type 1 and 55 Type 2, living in Hué (Vietnam) were selected and compared with 60 non-diabetic healthy Vietnamese controls (BMI = 20.8 +/- 0.2 kg/m(2)) and also European controls. CAN function was evaluated by five standardized tests: three tests for heart rate variations (HRV) which depend mainly on parasympathetic activity, and two tests for blood pressure (BP) response which depend mainly on sympathetic activity. With age taken into account, 41 of the 60 Vietnamese controls had at least mild CAN, as defined by one abnormal test for HRV when compared with the European control series, and 11 of them had two or three abnormal tests. Among the Vietnamese control men, those with abnormal HRV had lower BMI than those without (P = 0.036). Seven Vietnamese controls had postural hypotension and 16 had an abnormal BP response to the handgrip test. Compared with the Vietnamese controls, 71 diabetic patients (67.6%), 40 Type 1 and 31 Type 2, had at least mild CAN, 37 of them had two or three abnormal HRV tests, and 56 diabetic patients (53.3%) had an abnormal BP response to the sympathetic tests. Abnormal HRV were associated with significantly lower BMI, waist and hip circumferences, longer diabetes duration and higher fasting blood glucose. In the logistic regression analyses, abnormal HRV were associated significantly with duration of diabetes and BMI in patients with Type 2 diabetes. Cardiac autonomic dysfunction is frequent in normal Vietnamese subjects. CAN appears to be a more frequent complication of diabetes in Vietnam than in Western countries and diabetic parasympathetic dysfunction is frequently associated with sympathetic disorders. This confirms the deleterious effect a poor nutritional state has on cardiac autonomic function.