The influence of cardiovascular autonomic neuropathy on mortality in type 1 diabetic patients; 10-year follow-up

Abstract

Aim: The aim of our retrospective study was to answer the question if the presence of cardiovascular autonomic neuropathy (CAN) affects mortality in type 1 diabetic patients during a 10-year follow-up.

Methods: Patients with type 1 diabetes mellitus examined for CAN in 2003 were enrolled in this retrospective study. A total of 278 patients were included and divided into two groups according to the presence or absence of CAN (111 CAN+, 167 CAN-). The group characteristics and outcomes were compared at baseline and after ten years (in 2013).

Results: In the follow-up period, a total of 18 patients died; CAN+ (14/111; 12.6%) and CAN- (4/167; 2.4%) (P < 0.001). At baseline, the CAN+ patients were older (47 vs. 33 years; P < 0.001), had longer duration of diabetes (20 vs. 12 years; P < 0.05), had worse glycemic control assessed by HbA1c (73 vs. 68 mmol/mol; P < 0.05), higher systolic (130 vs. 120 mmHg; P < 0.001) and diastolic (80 vs. 70 mmHg; P < 0.01) blood pressure and had more diabetic complications. In our analysis we found the strongest predictor of mortality to be the presence of CAN (P < 0.01) and the blood pressure value at baseline (P < 0.05). Other baseline characteristics, including the duration of diabetes, age and the presence of micro- and macrovascular complications were not significant. The statistical analysis was performed using logistic regression step-wise analysis.

Conclusions: During the 10-year follow-up, CAN+ patients had a 5-fold higher mortality rate than CAN- patients. The strongest predictor of mortality was the presence of CAN.

Keywords: cardiovascular autonomic neuropathy; chronic complications; morbidity; mortality; type 1 diabetic patients.