April 25, 2006 -- Before your next blood pressure test, you might want to rest in a chair for at least five minutes.
Sitting on the exam table in the doctor's office isn't the same, according to new research presented in Denver at the Preventive Cardiovascular Nurses Association's 12th annual symposium.
Melly Turner, RN, and colleagues studied 100 adults who got blood pressure tests at the ambulatory cardiology clinic of the University of Virginia Health System, where Turner's team works.
Participants were about 63 years old, on average. They got their blood pressure checked while sitting in two positions:
- Seated in a chair with back support, both feet on the floor, arm supported at heart level
- Seated on an exam table, legs dangling, with no back support
In each position, participants had their blood pressure checked immediately and after waiting at least five minutes. The tests were given in random order.
Position, Timing Mattered
Systolic readings were higher when patients had their blood pressure checked immediately after sitting on the exam table compared with the sit-in-a-chair-and-wait strategy.
How big was the gap in systolic blood pressure? It was an average of about 14 points, the researchers report.
The data note an average systolic blood pressure reading of 133 when patients had their blood pressure checked immediately after sitting on the exam table. Average systolic blood pressure was nearly 117 after patients waited in the chair for at least five minutes before the exam.
Waiting on the exam table helped somewhat, but not as much as waiting in the chair, the study shows.
The researchers found no significant differences in diastolic blood pressure, the second number in a blood pressure reading.
Checking for 'White Coat Syndrome'
Some people get anxious around health care workers wearing white lab coats. That pattern, called "white-coat syndrome," can drive blood pressure up, but that didn't happen in Turner's study.
Patients got their blood pressure checked by health care workers wearing street clothes, surgical "scrubs," or a white lab coat over their clothes. Health care workers' dress didn't affect patient's blood pressure, the study shows.
The American Heart Association recommends the sit-in-a-chair-and-wait strategy, and the new data support that advice, note Turner and colleagues. Both position and timing matter when it comes to measuring blood pressure.