What is the most relevant definition of orthostatic hypertension:: systolic blood pressure's drop, diastolic blood pressure drop, or either?

The agreed definition of orthostatic hypotension (OH) is a drop of 20 mmHg systolic and/or 10 mmHg diastolic blood pressure (BP) within the first 3 min of erect posture. For elderly people, a question can be raised about diastolic BP relevance in OH's definition. Objective: To determinate HO's prevalence and risks factors considering systolic blood pressure (SBP)'s drop, or diastolic blood pressure (DBP)'s drop, or either. Methods: We assessed OH for 554 consecutive, ambulatory, elderly subjects, attending a geriatric outpatient clinic. OH was defined as a SBP drop > 20mmHg (SBP-OH), or a DBP drop > 10 mmHg (DBP-OH), or a drop in either (SBP. DBP-OH). OH's prevalence and risks factors were determined. Results: In this population, 76 6 years of age, (70% hypertension), SBP-OH's prevalence was 17%, DBP-OH's prevalence was 12% and SBP. DBP-OH's prevalence was 25%. OH's risks factors varied considering OH's definition. After adjusting for significant determinants, SBP-OH's risk factors were: Antihypertensive therapy (OR = 2.95; IC 95% 1.21-4.04), age > 75years (OR = 2.11; IC 95% 1.22-3.66), anti-hypertensive poly therapy (OR = 2.0 1; IC 95% 1.39-2.92) and SBP level (OR = 1.16; IC 9S%: 1.01-1.33). Considering DBP-OH, the only significant risk factor was DBP's level (OR = 2.64; IC 95% 1.89-3.68). SBP. DBP-OH was only determined by anti-hypertensive poly therapy (OR = 1.61; IC 95% 1.13-2.29) and DPB level (OR = 1.32; IC 95% 1.08-1.60). Conclusion: For elderly people, OH's prevalence and risks factors vary considering OH's definition. SBP's drop seems to be more relevant than DBP's drop. A long term follow up is necessary to determine if SBP-OH is correlated with HO' s side effects and to establish the dangerous level of SBP' s drop.