Association of heart rate and blood pressure variability with psychological state and physical performance in elderly / Nur Husna Shahimi

• Main Author: Nur Husna, Shahimi
• Format: Thesis
• Published: 2022
• Subjects: R Medicine (General); T Technology (General)
• Online Access: http://studentsrepo.um.edu.my/14863/1/Nur_Husna_Shahimi.jpg; http://studentsrepo.um.edu.my/14863/8/Husna.pdf; http://studentsrepo.um.edu.my/14863/
• Institution: Universiti Malaya

The issue of falls among older individuals is one of the most common public health problems which has become a global concern. In Malaysia, the prevalence of falls was 14% among community-dwelling older adults aged 60 years and above in the past year. Previous studies have established the associations between both autonomic function indicators; heart rate variability (HRV) and blood pressure variability (BPV) with fall recurrence, as well as physical inactivity and psychological disorders as risk factors for falls, however, the influence of these fall risk factors on autonomic dysfunction among older fallers has not been adequately investigated. Therefore, this thesis aims to: 1) identify the differences between elderly fallers and non-fallers in terms of psychological function, physical activity, physical performance and autonomic nervous system, 2) investigate HRV or BPV indices that are most closely correlated to physical activity or psychological disorder in elderly adults, 3) identify physical activity, physical performance or psychological disorder measures that best predict autonomic function indices. This was a cross-sectional study with 92 adult participants aged ≥60 years recruited from a tertiary hospital. Of those, forty-five older individuals who had at least one fall incident in the past two months were labelled as the fall cohort, while forty-seven older individuals with no history of fall in the past two months were labelled as the non fallers cohort. Continuous non-invasive blood pressure and heart rate was monitored over 5 minutes of supine rest and 3 minutes of standing upright. Subsequently, time domain and frequency domain analysis was performed on the continuous blood pressure signal to derive autonomic function indices (i.e., HRV and BPV). Findings based on comparison between fallers and non-fallers showed that fallers were significantly older, requiring longer time to complete Time-Up and Go test, having weaker hand grip strength and lower physical activity scale (PASE), as well as reduced functional dependency (Lawton IADL). The HRV and BPV results from this study indicated potential deterioration in the autonomic function in older fallers, as compared to non-fallers. Lawton Instrumental Activities of Daily Living (IADL) Scale and Physical Activity Scale for the Elderly (PASE) that indicate physical dependency and daily lifestyle of an individual were found to be the best independent predictors for autonomic function, as measured by the HRV and BPV indices. On the other hand, the stress and depression scores in the DASS-21 questionnaire best predict autonomic function (as measured by the HRV and BPV indices) during supine and standing, respectively. By knowing the association between these modifiable risk factors and autonomic function, early identification of patients at risk of recurrent falls and cardiovascular diseases can be performed to allow timely intervention.