DIAGNOSTICKÝ VÝZNAM SNÍŽENÉ CITLIVOSTI BAROREFLEXU A ZVÝŠENÉ TEPOVÉ FREKVENCE V ČASNÉM STADIU DIABETES MELLITUS I. TYPU
| Title in English | Diagnostic significance of decreased baroreflex sensitivity with respect to heart rate in type I diabetes mellitus |
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| Authors | |
| Year of publication | 2012 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Decreased baroreflex sensitivity is one of the early signs of autonomic dysfunction in patients with type 1 diabetes mellitus. We evaluated the repeatability of a mild baroreflex sensitivity decrease with respect to the heart rate. Finger arterial blood pressure was continuously recorded in 14 young diabetics without clinical signs of autonomic dysfunction and in 14 age-matched controls for 42 minutes. The recordings were divided into 3-minute segments, and the mean inter-beat interval (IBI), baroreflex sensitivity in ms mmHg-1 (BRS) and mHz mmHg-1 (BRSf) were determined in each segment. These values fluctuated in each subject within 42 minutes and therefore coefficients of repeatability were calculated for all subjects (89.1% for IBI; 62.9% for BRS; 65.8% for BRSf). Diabetics compared with controls had significantly decreased mean BRS (p<0.05), borderline-shortened IBI (p=0.08) and non-significantly decreased BRSf. We compared all combinations of 3-minute segments: diabetics compared with controls had significantly decreased BRS in 26% of segments, BRSf in 4% of segments, and IBI in 23% of data segments; significance of BRS depended on the significance of IBI, BRSf was IBI independent. The correlation coefficients between IBI and BRS were 0.58 (p<0.05) in diabetics and 0.43 (p=0.12) in controls. BRSf was IBI independent. We conclude that BRS is partially dependent on mean IBI. BRS reflects not only an impairment of the quick baroreflex responses of IBI to blood pressure changes, but also a change of the tonic sympathetic and parasympathetic heart rate control. This is of significance during mild changes of BRS. Therefore, examination of the BRSf index is also recommended. This study was supported by the grant project MUNI/A/0846/2011 |
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