title: [The influence of upright position on heart rate variability parameters in adolescents with hypertension and type 1 diabetes].
abstract: BACKGROUND
  The autonomic regulation of heart rate variability (HRV) is impaired not only in patients with type 1 diabetes but either in nondiabetic hypertensive patients.
  
  
  OBJECTIVE
  The aim of the study was to evaluate the HRV parameters in adolescents with type 1 diabetes depending on appearance of hypertension.
  
  
  METHODS
  The study group included of 34 patients with diabetes and hypertension aged 15+/-2.2, and 38 patients with diabetes without hypertension aged 15+/-2.9. The control group consisted of 55 healthy persons aged 15+/-2.2. In every examined person were performed tests of autonomic nervous system in accordance to Ewing battery and frequency-domain analysis of HRV during supine and standing position.
  
  
  RESULTS
  The HRV parameters: total power (TP), low (LF) and high frequency (HF) were significantly decreased in patients with hypertension during supine and standing as compared to control group (p<0.001). There were differences between diabetics without hypertension and autonomic neuropathy and control group. The appearance of CAN in patients without hypertension caused the decrease all HRV indices during supine (p<0.001), however the standing position only decrease of TP and HF (p<0.01). TP value was depending on glycated haemoglobin concentration (p<0.001), but there was no correlation between HRV indices and left ventricular mass index.
  
  
  CONCLUSIONS
  The decrease of HRV parameters in adolescents with diabetes type 1 is connected not only with autonomic neuropathy but also with appearance of arterial hypertension.
authors.affiliation: klchdz2@cksr.ac.bialystok.pl
authors.forename: M
authors.initials: M
authors.lastname: Kowalewski
authors.forename: M
authors.initials: M
authors.lastname: Urban