SOURCE: Townsend RR, Chang TI, Cohen DL, et al. Orthostatic changes in systolic blood pressure among SPRINT participants at baseline. J Am Soc Hypertens 2016;10:847-856.

Upon standing from a sitting (or supine) position, compensatory changes in heart rate and vascular tone maintain both systolic blood pressure and diastolic blood pressure fairly consistently. Postural changes in blood pressure of more than a 20 mmHg drop in systolic blood pressure or a 10 mmHg drop in diastolic blood pressure (or both) withing three minutes of standing are defined as orthostatic hypotension, although only a minority of individuals with measurable orthostatic hypotension experience any clinical manifestations such as dizziness, lightheadedness, or falls. On the other hand, orthostatic hypotension has been associated with worsened cardiovascular outcomes, even when asymptomatic.

Townsend et al reported on baseline data from the SPRINT trial, which collected data on orthostatic blood pressure changes in 8,662 participants at baseline. Overall, 7% (n = 634) of enrollees demonstrated orthostatic hypotension, although the element by which they met the diagnostic criteria for orthostatic hypotension varied: 294 subjects met systolic blood pressure criteria, 227 met diastolic blood pressure criteria, and 113 met both.

No one has suggested that asymptomatic orthostatic hypotension requires treatment. On the other hand, symptomatic orthostatic hypotension places patients at risk for falls with subsequent consequences as hip fractures, leading to increased mortality.

Because patients may not always be forthcoming about symptoms referable to orthostatic hypotension, more routine measurement of orthostatic blood pressure changes in hypertensive patients may help identify those at risk.