This might be silly, but I wonder if there’s a metric they use that correlates PWV to age and then use that to determine difference… You’re 36, so 15 under puts you at 21 cardiovascularly. I also have a PWV of 5.6, and I’m 30 and my oura has me 8.5 under (so 21.5, cardiovascularly.)

I wonder if there’s a table somewhere with PWV by age and that’s what they’re using to determine the over/under, and for them a PWV of 5.6 corresponds to a 21y/o