[Frequency and associated risk factors of cardiovascular autonomic neuropathy among patients with type 2 Diabetes.]

Background: Cardiovascular autonomic neuropathy (CAN) is a common complication of diabetes and is associated with cardiovascular morbidity and mortality. Despite its prevalence, it is usually underdiagnosed. Objective to assess frequency of CAN in type 2 diabetes, treated at the Diabetology Service at Cordoba Hospital, Argentina.
Method: Cross-sectional study was conducted from May 2015 to May 2016. Cardiovascular Autonomic Tests (Ewing´s battery) were performed: response to Valsalva maneuver, expiration-to-inspiration ratio (E/I ratio), standing to lying flat and postural hypotension.
Results: 100 type 2 diabetes patients, 53% females. The mean age and diabetes duration 52 years old and 8.4 years, respectively. Hemoglobin A1c level of 8.7% and 47% were insulin-requiring type 2 diabetes patients. 29% had early CAN, 54% confirmed CAN (10% severe CAN) and 17% normal cardiovascular tests. Confirmed CAN was higher in those with longer duration of diabetes; longer duration of insulin therapy, older patients and severe hypoglycemia events was higher in those with confirmed CAN versus without CAN or early CAN (p 0.003). The risk factors associated were hypertension OR 2.55 (p 0.02), peripheral neuropathy OR 11.7 (p <0.0001), diabetic retinopathy OR 9.03 (p 0.001), diabetic nephropathy OR 3.12 (p 0.03) and hemoglobin A1c > 7% OR 2.57 (p 0, 03).
Conclusions: frequency of CAN was high, was associated with hypertension, microvascular complications, older age, poor metabolic control, longer duration of disease and insulin therapy. Patients with a higher risk of developing CAN should be identified, in order to reduce the impact of this complication.