| 1. |
- Passant, Ulla, et al.
(författare)
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Orthostatic hypotension in organic dementia: relationship between blood pressure, cortical blood flow and symptoms
- 1996
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Ingår i: Clinical autonomic research : official journal of the Clinical Autonomic Research Society. ; 6:1, s. 29-36
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Tidskriftsartikel (refereegranskat)abstract
- Regional cerebral blood flow was measured in 35 patients with organic dementia (Alzheimer's disease, n = 13, vascular dementia, n = 17, frontotemporal dementia, n = 5) and orthostatic hypotension. Measurements were performed during supine rest and during head-up tilt (60 degrees). Despite marked blood pressure falls, few patients had symptoms of orthostatic hypotension. All three dementia groups had a decrease in regional cerebral blood flow in the frontal lobes during head-up tilt, but no change in mean hemispheric flow. All patients had a consistent drop in their systolic blood pressure upon head-up tilt, with a wide variation over time. The findings suggest that orthostatic hypotension needs to be considered, and actively sought for, in organic dementia as many patients may lack the typical symptoms of orthostatic hypotension, despite a marked fall in blood pressure.
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| 2. |
- De Kanter, M., et al.
(författare)
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A prospective study of orthostatic blood pressure in diabetic patients
- 1998
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Ingår i: Clinical Autonomic Research. - 0959-9851. ; 8:4, s. 189-193
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Tidskriftsartikel (refereegranskat)abstract
- To clarify whether orthostatic blood pressure is affected by the type of diabetes, cardiac autonomic neuropathy, and the duration of diabetes, orthostatic blood pressure (passive 90°tilt) was evaluated in 102 patients with insulin dependent diabetes mellitus (IDDM), 51 patients with non-insulin dependent diabetes mellitus (NIDDM), and in 238 control subjects in a first study followed up after 8 to 17 years. The heart rate reaction during deep breathing (E/I ratio) and to tilt (acceleration and brake indices) assessed cardiac autonomic function. In the first study, the lowest systolic blood pressure (LSBP) and the lowest diastolic blood pressure (LDBP) after tilt were significantly lower in IDDM patients compared with NIDDM patients (p < 0.001 for LSBP and p < 0.05 for LDBP) and controls (p < 0.001). LDBP was, however, also significantly lower (p < 0.05) in NIDDM patients than in controls. Hence, although most severe in IDDM, LDBP was disturbed in both types of diabetes. In IDDM, a low E/I ratio was associated with disturbed orthostatic blood pressure. At follow-up examinations, orthostatic blood pressure deteriorated in NIDDM but not in IDDM patients. In conclusion, LSBP and LDBP were impaired in IDDM patients compared with NIDDM and control subjects; however, LDBP was also impaired in NIDDM patients compared with controls. When the duration of diabetes increased, orthostatic blood pressure deteriorated in NIDDM but not in IDDM patients.
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| 3. |
- Lind, H, et al.
(författare)
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Selective attenuation of neuropeptide-Y-mediated contractile responses in blood vessels from patients with diabetes mellitus
- 1995
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Ingår i: Clinical Autonomic Research. - 1619-1560. ; 5:4, s. 191-197
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Tidskriftsartikel (refereegranskat)abstract
- Vascular smooth muscle contractile responses to neuropeptide Y, alpha,beta-methyleneATP and noradrenaline were studied in circular segments of isolated vessels with intact endothelium in vitro from 12 patients with diabetes mellitus type 2 (NIDDM) and 12 control subjects. The dilatory effect of acetylcholine was used to test the function of the endothelium. Subcutaneous arteries and veins (diameter 0.1-1.1 mm) were obtained during surgery. There was no difference in contractile responses to noradrenaline or alpha,beta-methyleneATP between diabetic and control vessels. The contractile response to neuropeptide Y, however, was markedly reduced in the diabetic group. The maximal contractile effect (46.0 +/- 14.0%, p < 0.05) but not the sensitivity to neuropeptide Y was significantly less in diabetic veins compared to control (107.5 +/- 19.6%). Thus, the attenuation of neuropeptide Y responses was present in humans as previously observed in alloxan-induced diabetes mellitus in rabbits. There was no difference in the dilator effect of acetylcholine between the diabetic and the control group in any of the vessel types, indicating that the difference in vascular reactivity to neuropeptide Y was not endothelium-dependent. In conclusion, the present study has shown that the postjunctional effects of neuropeptide Y, a co-transmitter of the peripheral sympathetic nervous system, is selectively attenuated in diabetes mellitus.
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