Baroreflex sensitivity in patients with type I diabetes mellitus

OBJECTIVES: To date, the clinical usefulness of measuring baroreflex sensitivity (BRS) to detect impairment of the autonomic nervous system in patients with diabetes mellitus (DM) type I has not been evaluated sufficiently (Mlcakova et al. 2008). The aim of the current study was the determination and statistical comparison of the mean values of BRS in our DM type I patients cohort and in a control group of healthy volunteers as well as the determination of BRS value dependency on the duration of diabetes and the level of glycemic control in DM I patients. We also aimed to determine the inter-individual and intra-individual variability of BRS in our patients. MATERIAL AND METHODS: We examined 100 patients with type I diabetes mellitus (37 women and 63 men, mean age 30 years, duration of the disease >= 10 years) and 40 healthy, age- and sex-matched, subjects. Data from the patient cohort were subsequently analysed for duration of the diabetes and the level of glycemic control as assessed by glycated haemoglobin (HbA1c). We used a simple proportional test to compare the occurrence of impaired BRS in the patient cohort and the control group, and a simple linear regression to assess associations between BRS and duration of the diabetes and the levels of glycemic control. RESULTS: The mean BRS value in our group of diabetic patients and the control group were 10.15 ms/mmHg and 13.35 ms/mmHg, respectively. II. Statistically significant association between BRS impairment and the duration of the disease or level of glycemic control was not confirmed in our patient cohort. III. We observed an increased inter-individual variability and a relatively low intra-individual variability of BRS in patients with DM type I. CONCLUSIONS: We found a statistically highly significant difference between the proportions of impaired BRS in the group of diabetics vs. control. However, BRS did not correlate with the duration of the disease or with the level of glycemic control significantly. Albeit not reaching statistical significance, trends could be observed, which we consider clinically interesting.