Are Nighttime Blood Pressure Monitors Causing Patients to Lose Sleep?
Patients who rely on nighttime blood pressure monitoring may be losing sleep, according to the Clinical Journal of the American Society of Nephrology. The main concern expressed in this study is how sleep disturbances may ultimately affect the test results.
According to Dr. Rajiv Agarwal of the Veterans Affairs Medical Center in Indianapolis, blood pressure monitor measurements taken during sleep are a better way to predict heart disease than tests administered in doctors’ offices. But Dr. Agarwal’s concern is that sleep disturbances may make it more difficult to assess the relationship between sleeping blood pressure tests and certain cardiac events.
After analyzing the results of 24 hour BP monitoring in over 100 patients with kidney disease, Dr. Agarwal noted certain variations in test results between those taken during the day and those taken at night. Cardiologists know that blood pressure usually dips during the night, and when that doesn’t happen, a patient is considered to be at much higher risk for cardiovascular events.
In most cases, patients were monitored during the night using an “Actiwatch device” strapped to their wrists. However, because the blood pressure monitors themselves were disturbing sleep patterns in many patients and causing increased activity during the night, the customary “dip” that would normally occur wasn’t happening. In fact, when patients were using the blood pressure monitor at night, they spent about 90 minutes less time in bed and slept less, causing them to sleep less soundly.
As a result, Dr. Agarwal suggests that sleep quality be a factor in deciding whether “sleeping BP” results are an accurate assessment of overall cardiac health.