Orthostatic hypotension in older adults New approaches to fall risk assessment

Falls are a major public health concern among older adults. Orthostatic hypotension (OH) contributes to unexplained and recurrent falls, yet optimal assessment remains uncertain. This thesis aimed to identify key risk factors and parameters associated with OH-related falls and improve fall risk assessment using systems thinking, continuous beat-to-beat blood pressure (BP) monitoring, and near-infrared spectroscopy (NIRS)-based cerebral oxygenation monitoring.
An evidence map and scoping review identified useful cardiovascular diagnostics and treatments but found limited evidence for their effectiveness. A causal loop diagram revealed complex mechanisms underlying OH-related falls. Decreased cerebral blood flow, low BP, impaired baroreflex activity, and physical inactivity emerged as central factors. Continuous BP monitoring showed that fallers had lower resting BP, lower BP nadirs, and delayed recovery after standing. Supine-to-stand testing detected OH and impaired BP responses more effectively than sit-to-stand testing. NIRS monitoring showed that early cerebral oxygenation impairments during supine-to-stand were associated with falls, whereas no significant associations were observed during sit-to-stand.
Overall, this thesis demonstrates the value of assessing dynamic cardiovascular and cerebral responses, particularly during the early phase after standing. Systems thinking, continuous BP and cerebral oxygenation monitoring may support more individualized diagnosis and prevention of OH-related falls, although further validation and standardized diagnostic thresholds are needed.