Purpose: Consensus definitions currently define initial orthostatic hypotension (IOH) as ≥ 40 mmHg systolic (SBP) or ≥ 20 mmHg in diastolic blood pressure (DBP) reductions within 15 s of standing, while classical orthostatic hypotension (COH) is defined as a sustained reduction ≥ 20 mmHg SBP or ≥ 10 mmHg SBP within 3 min of standing. The clinical relevance of the aforementioned criteria remains unclear. The present study aimed to determine factors influencing postural blood pressure changes and their relationship with physical, functional and cognitive performance in older adults.
Methods: Individuals aged ≥ 55 years were recruited through the Malaysian Elders Longitudinal Research (MELoR) study and continuous non-invasive BP was monitored over 5 min of supine rest and 3 min of standing. Physical performance was measured using the timed-up-and-go test, functional reach, handgrip and Lawton's functional ability scale. Cognition was measured with the Montreal Cognitive Assessment. Participants were categorized according to BP responses into four categories according to changes in SBP/DBP reductions from supine to standing: < 20/10 mmHg within 3 min (no OH), ≥ 20/10 mmHg from 15 s to 3 min (COH), ≥ 40/20 mmHg within 15 s and ≥ 20/10 mmHg from 15 s to 3 min (COH + IOH) and ≥ 40/20 mmHg within 15 s and < 20/10 mmHg within 3 min (IOH).
Results: A total of 1245 participants were recruited, COH + IOH 623 (50%), IOH 165 (13%) and COH 145 (12%). Differences between groups existed in age, gender, hypertension, diabetes, use of alpha-blocker and/or beta-blocker, ACE-inhibitors, diuretics, biguanides, and baseline systolic BP. In univariate analyses, differences between groups were present in physical performance and cognition. Multivariate comparisons revealed better physical performance in IOH compared to no OH, better physical and cognitive performance in COH + IOH compared to no OH, and cognition in COH than no OH.
Conclusion: Our findings suggest that older adults who fulfil current consensus definitions for IOH had better physical performance and cognitive scores. This indicates that an initial postural BP drop in people aged ≥ 55 years may not necessarily be associated with increased frailty, as suggested by previously published literature.
Keywords: Aged; Cognition; Functional impairment; Initial orthostatic hypotension; Orthostatic hypotension.