It’s not just those wild and crazy dreams which distinguish sleep from the world of daytime activities. Blood pressure normally drops and levels of certain hormones may rise or fall. It has been shown that disruption of normal sleep as is seen in night shift workers increases the risk for cancer and heart disease. What about blood pressure control?
A recent study in which blood pressure was measured before, during and after sleep found that blood pressure measurements during sleep affect the risk of having a heart disease years down the road. People whose blood pressure dropped more than about 10% during their sleep suffered fewer heart attacks or anginal episodes than those whose blood pressure dropped less than 10%.
The idea is that during sleep the body restores itself:systems are repaired and hormones tailored to maximize performance. Changes in blood pressure would therefore have a greater effect during this time of restoration than say during the day. You might think that that idiot who is flipping you off over some lane change that you made would have his blood pressure go through the roof. Indeed, he might, but at least for him, his risk of having heart attack would be much smaller if he flipped you off at say 4 pm rather than 4 am.
To put it another way, you get more bangs for your bucks if you control that blood pressure better at night than during the day. Practically, this means that blood pressure medications might be better taken at night than during the day, and might need to be tailored so that the maximum effects occur during sleep rather than when sitting at that work desk, pondering over some confusing tasks your boss has just given you.
Before you start chugging all those blood pressure pills along with that nighttime glass of vino, you should realize that this was a single study. More need to be done to confirm these effects. I am quite sure that the drug companies are licking their chops, and actively searching for medications which will lower the pressure the most at night.