ORTHOSTATIC BLOOD PRESSURE PHENOTYPES IN OLDER ADULTS WITH HYPERTENSION AND THEIR ASSOCIATION WITH CLINICAL FRAILTY

Objective: The association between frailty and orthostatic hypotension (OH) is well-established, with similar patterns reported for orthostatic hypertension (OHT). However, the dynamic nature of orthostatic blood pressure (BP) phenotypes -where individuals may transition between OH and OHT during assessment- remains unclear. The impact of frailty on these transitions is poorly understood. This study aimed to characterize orthostatic BP changes during clinical examination in older adults with treated hypertension, investigating their relationship with frailty and orthostatic intolerance (OI). Design and method: A cross-sectional study was conducted at a tertiary hypertension center, including patients aged over 60 years. Frailty was assessed using the Clinical Frailty Scale (CFS), with participants categorized as non-frail (CFS <5) or frail (CFS 5 or greater). Orthostatic BP was measured at 1 and 3 minutes post-standing. OH and OHT were defined as a decrease or increase in systolic BP (SBP) of at least 20 mmHg or diastolic BP (DBP) of at least 10 mmHg. OI was defined as symptoms upon standing. Logistic regression models evaluated associations between frailty, OI, and orthostatic BP phenotypes. Results: We included 461 hypertensive adults (mean age: 72.5 ± 7.0 years, 70% female, mean sitting SBP/DBP: 150 ± 23/79 ± 12 mmHg), classified as frail (10.4%, n=48) or non-frail (89.6%, n=413). Orthostatic BP phenotypes and transitions are shown in the Sankey Diagram (Fig 1). About 50% of individuals with OH or OHT at minute 1 normalized their BP by minute 3, while a similar absolute number with normal BP at minute 1 developed OH or OHT by minute 3. Frail individuals were more likely to report OI (19.6% vs. 10%, p=0.048), with increased likelihood of OHT (25% vs. 9%, p<0.001) and OH (21% vs. 10%, p=0.02). Diastolic OH (OR 3.32, p=0.01), but not systolic OH (OR 1.29, p=0.642), was significantly associated with frailty (Fig 2). Conclusions: Frailty was associated with abnormal orthostatic BP responses, particularly diastolic OH and OHT, and with OI. Orthostatic BP phenotype transitions between the first and third minute highlight the importance of repeated measurements to ensure reliable assessment.