Autonomic regulation of cardiovascular system in patients with type 1 diabetes mellitus with arterial hypertension and normal blood pressure

Abstract

Objective. To determine whether cardiac autonomic neuropathy (CAN) influences the development of arterial hypertension (HTN) in patients with type 1 diabetes mellitus (T1DM). Design and methods. We examined 60 patients with T1DM (37 women and 23 men, mean age 40,3 ± 1,3 years) and 40 healthy controls (21 women and 19 men, mean age 30,0 ± 0,6 years). Clinical symptoms of CAN as well as instrumental parameters were assessed. The following methods were used: spectral analysis of heart rate variability, blood pressure changes during tilt-test, the Valsalva maneuver, test with deep respiration, hand-grip and cold-pressor test, an index 30/15, arterial and cardiopulmonary baroreflexes. Blood pressure monitor (Finometer) and occlusion plethysmograph (Dohn) with parallel registration of electrocardiogram were used for data assessment. Results. Clinical symptoms of CAN had 39 patients with T1DM (65%), in 30 of them CAN was confirmed by instrumental methods. In 9 patients without clinical manifestations CAN was diagnosed instrumentally. The most frequent disorders in T1DM patients were the reduction of spontaneous arterial baroreflex (69%), cardiopulmonary baroreflex (64%), and heart rate variability (49%). HTN was diagnosed in 37 T1DM patients (62%) and was more frequent in patients with autonomic dysfunction (р < 0,05).The patients with CAN had longer duration of HTN (5,7 ± 2,80 vs 2,3 ± 2,80 years, р < 0,05) and higher HTN degree (χ2 = 8,06, р < 0,01) than patients without CAN. Conclusions. Cardiac autonomic neuropathy contributes to the development of HTN in T1DM patients. Implementation of instrumental methods for timely diagnosis of CAN is reasonable in T1DM patients.