Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Niehaus, T.
Hormonal Changes during Orthostatic Challenge in Patients with Stroke
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2017. pp.
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Fazekas Franz
- Goswami Nandu
- Altmetrics:
- Abstract:
- Background: Orthostatic intolerance is a common complication in patients with stroke. Frequent falls are the result, which often leads to severe injuries and consequently, longer periods of immobilization and hospitalization. Orthostatic intolerance can arise when there are inadequate neuro-hormonal responses to an orthostatic challenge. Therefore, it is important to assess cardiovascular, autonomic and hormonal responses to orthostatic challenge in patients with stroke. It has previously been shown that hormonal responses such as those of the novel neuro-peptide adrenomedullin increase due to orthostatic challenge in a stimulus-dependent manner, but changes in the hormone galanin only occur at the end point of cardiovascular stability leading to orthostatic intolerance. Aims: The objective of this study was to investigate the effects of an orthostatic challenge on adrenomedullin and galanin responses in patients with a history of ischemic stroke and to see how they compared with age-matched healthy controls. We hypothesized that i) baseline adrenomedullin and galanin levels in stroke patients are higher than in healthy controls; ii) adrenomedullin and galanin levels increase due to orthostatic challenge; and iii) adrenomedullin and galanin responses during an orthostatic challenge differ in stroke versus healthy controls. Methods: Thirteen patients with a history of mild ischemic stroke (NIHSS = 3) and eighteen age-matched healthy controls performed a sit-to-stand test (five minutes sitting and six minutes standing period). Venous blood was sampled prior to - and at the end of - standing. Results: At baseline, no significant differences in plasma adrenomedullin and galanin concentrations between the two groups were seen. Furthermore, changes in posture from sitting to standing did not induce a significant change in hormonal concentrations across both groups. Conclusions: In patients with a history of mild ischemic stroke up to one year, the baseline status of adrenomedullin and galanin was similar to healthy patients. Additionally, mild orthostatic challenge did not influence plasma adrenomedullin and galanin concentrations in patients with histories of ischemic stroke and healthy controls. Our results differ from previous observations regarding these hormones in stroke patients as we used patients with histories of stroke of up to one year.