Sit-up Test for Assessing Blood Pressure Dysregulation in Community-Dwelling Older Adults: A Cross-Sectional Study

Background The sit-up test enables the assessment of orthostatic hypotension without using a tilt table in individuals at high risk of falling when standing; however, no studies have compared blood pressure responses between those with and without orthostatic hypotension during this test. The primary objective of this study was to compare blood pressure responses during the sit-up test between community-dwelling older adults with and without orthostatic hypotension. The secondary objective was to determine the associations between orthostatic hypotension detected by the sit-up test and poor health conditions in these individuals. Methods One hundred-two community-dwelling older adults underwent the sit-up test. Orthostatic hypotension was defined as a decrease of ≥10 mmHg in systolic blood pressure and/or ≥5 mmHg in diastolic blood pressure during the test. Supine and seated hypertension were evaluated, defined as systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg. Blood pressure responses during the test were compared between participants with and without orthostatic hypotension. Moreover, associations of orthostatic hypotension with demographic, clinical, and geriatric outcomes were examined. Results Thirty-four participants (33.3%) showed orthostatic hypotension during the test. Participants with orthostatic hypotension demonstrated a greater decrease in systolic blood pressure (F (3,297) = 47.0, p < 0.001), a smaller increase in diastolic blood pressure (F (3,297) = 26.5, p < 0.001), and higher supine systolic blood pressure (t = 3.363, p = 0.005) during the test than those without orthostatic hypotension. Consequently, 52.9% of participants with orthostatic hypotension had supine hypertension. Orthostatic hypotension was associated with a higher proportion of participants with at least one comorbidity (odds ratio = 4.50, p = 0.002) and those with non-robust status (odds ratio = 3.08, p = 0.022), even after adjusting for supine and seated hypertension. Conclusion Community-dwelling older adults with orthostatic hypotension were characterized by an impaired orthostatic increase in diastolic blood pressure and high supine systolic blood pressure during the sit-up test. Orthostatic hypotension was associated with poor health conditions, independently of supine and seated hypertension. These findings contribute valuable insights for the application of the sit-up test in preventive health screenings for older adults.