The diastolic vs systolic question is quite interesting. It's based on "expert opinion," and, to be fair, it seems sensible that a raised diastolic (which accounts for 2/3's of the cardiac cycle), is more damaging than a raised systolic (which accounts for 1/3 of the cardiac cycle). Outcome based studies refute this
As you say, a very interesting topic ! Scientifically speaking, about as easily determined as the toss of a coin !
The distinction is further blurred in that we simply do not have any treatments at all which specifically target either of the BP parameters individually.
Seasonal greetings to you too !
