Subclinical diagnosis of cardiovascular autonomic neuropathy in type 2 diabetes: prevalence, severity, correlations with time, metabolic and vascular factors

Abstract

Objective: To diagnose cardiovascular autonomic neuropathy in the general population of type 2 diabetes in our geographical area and determine its prevalence, severity and correlation with time, metabolic and vascular factors. Patients and method: 212 type 2 diabetic patients (49% men), ages 20-80 years (mean age: 52+-5.10 years) were examined by 5 autonomic reflex tests: 1. deep breathing test 2. Valsalva test; 3. heart rate response during stand test; 4. orthostatic blood pressure response; 5. diastolic blood pressure response during isometric exercise. Cardiovascular autonomic neuropathy (CAN) was defined by at least 2 abnormal results. Total vegetative score was also calculated, associating to each test a conventional value of 0/0.5/1 and severity stages were defined. Results: The overall prevalence of CAN was high (62,26%). CAN was clinically evident in 3% of patients only. Early and mild forms were predominant. CAN correlated well with: age, disease duration, HbA1C, body mass index (BMI), systolic blood pressure and did not correlate with gender. Conclusion: Autonomic impairment is an early finding in type 2 diabetes which may go unnoticed long before clinical history is positive. Active diagnosing CAN by autonomic function tests in its subclinical phase would enable a closer metabolic control and prevent further deterioration.