Diabetic autonomic neuropathy (DAN) commonly complicates diabetes and is associated with increased mortality rates over 5 yr. This fact denotes the significance of DAN prevention, mainly with effective glycemic control. However, total prevention of autonomic neuropathy in diabetic patients is not achievable. Thus, the timely detection of DAN and the use of effective means to improve autonomic nervous system function or slow down its progression become of utmost significance. Heart rate variability (HRV) is a technique that measures the beat-to-beat variability in RR intervals, which reflects changes in autonomic activity and their impact on cardiovascular function. Circadian variation in time and frequency domains of heart variability has been shown to correlate with circadian rhythm of ambulatory ischemia and suggests that relative changes in vagal and sympathetic tone at different times during the day may have a direct relationship to the severity of clinical events. Forty-seven (21 boys and 26 girls) type I insulin-dependent diabetics and 46 control subjects (19 boys and 27 girls) were included in the study. Our investigation demonstrated that overall HRV is markedly depressed in diabetes mellitus (DM). All time domain parameters except standard deviation of all 5-min mean RR intervals and all frequency domain indices maintain significant circadian variation. These changes in overall HRV and HRV circadian rhythms reflect significant reductions in cardiac parasympathetic activity and, possibly, increased sympathetic tone.

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Elevated levels of atherosclerotic/ inflammatory risk factors, low haemoglobin levels and loss of residual renal function and their negative effects on heart are of remarkable importance in paediatric patients on maintenance peritoneal dialysis. Achieving recommended targets for haemoglobin, blood pressure and Kt/V urea, preserving residual renal function as well as managing inflammation and subsequent arteriosclerosis is obviously essential to improve the patients' prognosis.

Objective: The objective of this study is to investigate endothelial dysfunction (ED) and arterial stiffness (AS) and determine the association with diastolic dysfunction in children with type 1 diabetes mellitus (DM). Methods: A total of 42 patients without diabetic complications (mean age: 13.21 years) and 40 healthy (mean age: 13.07 years) children were included in this study. AS was assessed with ascending aorta M-mode measurements, diastolic dysfunction with pulsed wave (PW) Doppler and tissue Doppler echocardiography measurements and flow-mediated dilatation (FMD) and carotid intima-media thickness (CIMT) with high-resolution ultrasonography. Results: Results of diabetic group and healthy children were compared. In diabetic group, aortic strain (8.40 ± 2.98, 20.12 ± 5.04; p < 0.001), aortic distensibility (7.36 ± 2.92, 16.59 ± 4.25; p < 0.001) and FMD% (7.70 ± 2.83, 11.33 ± 2.85; p < 0.001) were found decreased, and CIMT (0.52 ± 0.09 mm, 0.47 ± 0.08 mm; p < 0.05) was found increased. Additionally, left ventricular lateral segment and right ventricular free-wall isovolumic relaxation time (IVRT) and myocardial performance index (MPI) were found increased. Correlation analyses demonstrated a negative correlation between FMD and IVRT and MPI. Conclusions: ED and AS were found in type 1 DM patients without diabetic complications. Additionally, correlation was shown between increased AS and ED and right and left ventricular diastolic dysfunctions.

The results indicate that impairment of autonomic nervous system function in IPD without autonomic symptoms is frequent, and does not show clear association with clinical stage and the age of the patients.