Spontaneous baroreflex sensitivity in subjects with type 1 diabetes with and without cardiovascular autonomic neuropathy.
BACKGROUND
The clinical usefulness of baroreflex sensitivity (BRS) in the early detection of autonomic dysfunction in patients with diabetes is not well established. The aim of the study was the evaluation of BRS in subjects with type 1 diabetes with and without cardiovascular autonomic neuropathy (CAN).


METHODS
The group examined consisted of 39 patients with type 1 diabetes (mean age 30.5 +/- 8.8 years; diabetes duration 12.1 +/- 6.9 years; BMI 23.7 +/- 2.8 kg/m2; HbA(1c) 7.6 +/- 1.9%). The control group consisted of 18 sex and age-matched healthy adults. Blood pressure, heart rate and chest respiratory movements were monitored continuously by non-invasive means (Portapres). In order to recognise CAN standard Ewing tests were performed. BRS was assessed in the lying (L-BRS) and standing (S-BRS) positions by the frequency domain technique.


RESULTS
Ten patients (25.6%) had CAN (the CAN(+) group). In the CAN(+) group BRS was significantly lower than in the CAN(-) group in the lying and standing positions (respectively L-BRS 4.4 +/- 2.1 vs. 10.0 +/- 4.9 ms/mm Hg; p < 0.05; S-BRS 3.3 +/- 1.6 vs. 7.0 +/- 2.2 ms/mm Hg p < 0.001). BRS did not differ significantly between the CAN(-) and control group (respectively L-BRS 10.0 +/- 4.9 vs. 13.1 +/- 5.5 ms/mm Hg p = NS; S-BRS 7.0 +/- 2.2 vs. 7.9 +/- 4.0 ms/mm Hg p = NS).


CONCLUSIONS
BRS differentiated well the subjects with CAN from the group without CAN. However, the study did not enable us to confirm the value of BRS in the early detection of autonomic dysfunction among patients with type 1 diabetes who showed no abnormalities in standard cardiovascular tests.
Kamińska
Anna
A
Chair and Department of Endocrinology and Diabetology, Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University, Toruń. amikam@wp.pl
Tafil-Klawe
Małgorzata
M
Smietanowski
Maciej
M
Bronisz
Agata
A
Ruprecht
Zofia
Z
Klawe
Jacek
J
Junik
Roman
R
D000328:Adult; D017704:Baroreflex; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity