Circadian and Diurnal Regulation of Cerebral Blood Flow, review article by Webb et al, 2024

[kushami]

https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.123.323049

A fairly long review article, but this graph of blood pressure, heart rate and a cerebral measure gives a quick look at how it changes:

 

[kushami]

I presume this is based on subjects getting out of bed at about 7am, going to bed at about 11pm, and not doing anything too strenuous during the day, so as to reveal a general pattern.

Interesting that BP and HR go up suddenly when people get out of bed, but they don’t have a corresponding sudden drop in cerebral blood flow from moving to an upright position (not even a small one).

When the Lumia earpiece gets out to lots of users and especially to researchers it will be most interesting to see a graph of what happens to the cerebral blood flow on average for 50 or 100 people with ME/CFS or any condition that affects cerebral blood flow under similar daily conditions, and of course also when people are bedbound.

 

[cfs since 1998]

When the Lumia earpiece gets out to lots of users and especially to researchers it will be most interesting to see a graph of what happens to the cerebral blood flow on average for 50 or 100 people with ME/CFS or any condition that affects cerebral blood flow under similar daily conditions, and of course also when people are bedbound.

Ever since I got worse suddenly last year, whenever I even just sit up in bed I can feel blood draining from my face/head. It feels like sand falling in an hourglass.

 

[kushami]

This section is also of interest to ME/CFS:

Blood viscosity, a key determinant of CBF and blood flow velocity,117 also displays diurnal variation. More than 5 decades ago, Seaman et al118 reported that hematocrit, total protein, hexosamine, protein-bound carbohydrate, and blood viscosity were high early in the morning. During diurnal cycles of human inactivity and bed rest, blood plasma volume is reduced by dehydration as gravitational forces shift plasma constituents to interstitial spaces and increase water excretion.119

CBF = cerebral blood flow

The last sentence means something like “when you lie down at night to sleep, fluid distribution in the body changes and you pee out more than you do during the day, leaving you mildly dehydrated by morning” – and this process also wakes you up to pee during the night, a serious design flaw in the human body!

 

[Dysfunkion]

Interesting this matches my energy patterns well. I feel best at peak blood pressure times in the morning and I feel the absolute worst in the middle of the afternoon which slowly raises from 3 PM to 4 PM and then remains steady till it sharply drops off late at night into the early morning. In the bubble of 9-10:30 PM I will also also have a period of intense exhaustion though that will feel like I'm about to faint and nothing will be able to remedy the issue until the time passes and shortly after it does I'm ready for bed. I need to be up around 4:45 AM for work and that is when I feel terrible then but not quite as terrible as the 1-3 PM drop which makes me feel like a zombie. At 4:45 AM things aren't turned on but I'm more cognitively functioning.