Snooze Control
Nighttime habits may push up daytime pressure. For some people, it’s what’s going on at night, not during the day, that could be pushing their blood pressure to the upper limits. And this nocturnal stress has nothing to do with leaky faucets, noisy neighbors or worries about bills.
It’s about sleep and how lapses in it may cost you more than a few winks. When your breathing during sleep regularly stops for 10 seconds or more, researchers call it sleep apnea. Scientists know that these pauses in breathing send your blood pressure and heart rate skyward. And they’re speculating that a steady diet of these spikes may cause changes in hormones, blood vessels and nerve tissues that could keep the pressure up for good. Recently when blood pressure was measured every 20 to 30 minutes for 24 hours, researchers saw that blood pressures in 53 people with sleep apnea were consistently higher than they were in 53 people who simply snored (the mildest form of sleep-disordered breathing) and in 41 smooth sleepers. So strong is the link between apnea and high blood pressure that apnea is now considered an independent risk factor for hypertension. “Sleep apnea may turnout to be one of the mechanisms behind essential hypertension,” says study leader Khin Mae Hla, M.D. It might explain why as many as 30 percent of Americans have high blood pressure, yet more than 90 percent of cases, as of now, have no known cause. Dr. Hla is an associate professor in the department of medicine, University of Wisconsin School of Medicine, Madison.
“Sometimes, doctors just treat the blood pressure and don’t ask about sleep history,” says Dr. Hla. And that might leave a lot of hypertensives to be treated with drugs when they might be tested and treated for sleep apnea instead. Questions about sleep may be essential since research has shown that apnea is more common than was thought.
“Losing weight is one way of trying to improve sleep-disordered breathing, and that might also improve blood pressure,” says Dr. Hla. If your weight is on target, you can try an all-night mask that uses air pressure to keep the airway free of obstruction (called “continuous positive airway pressure, “or CPAP). Simpler strategies, such as not sleeping on your back and avoiding alcohol, may also resolve the problem. The current state-of-the-art diagnostic test for sleep apnea is to get an overnight polysomnogram (a full sleep study), which is available through sleep disorders clinics in major medical centers.