Saturday, 6 September 2014

Fun with maths: How many grams of "X" does it take to achieve "Y" mmol/L of "X" in the blood?

There are ≤3 fuels in blood - Glucose, Palmitic acid (FFA) & Beta-HydroxyButyric acid (Ketone body).

Taking blood volume as 5L (a petite woman has less):-

5mmol/L of Glucose ≡ 4.5g of Glucose.

1mmol/L of Palmitic acid ≡ 1.28g of Palmitic acid.

6mmol/L of Beta-HydroxyButyric acid ≡ 3.12g of Beta-HydroxyButyric acid.

Instead of going on a ketogenic diet (with all of the health hazards associated with it), why not just add Beta-HydroxyButyric acid to your drinks?

There's a problem. All metabolic fuels produce an insulin response (from functioning pancreatic beta cells) - this is one of the ways the level of each fuel is regulated in a NFB loop. Therefore, drinking more than 3.12g of BHB (more than 2.76mL) produces a large insulin response, which results in sleepiness. Ditto for GHB.


Vim said...

I don´t see any insulin response in the graph you show along with raising ketones.

Nigel Kinbrum said...

That's because they're endogenous ketones produced by starvation. It takes only a tiny increase in endogenous insulin production to stop endogenous ketone production from increasing any further, so you can't see it on the above graph.

Exogenous ketones are a different matter entirely, as they force the NFB loop to run open-loop.

Vim said...

Thanks Nigel, but can you elaborate better that "exogenous ketones are a different matter entirely"? Any references?

Nigel Kinbrum said...

Some things just don't have references. You're going to have to take my word as an Engineer on this.


If exogenous ketones raise serum ketones to >6mmol/L, this forces the loop to run open, which results in a large increase in insulin level, as the output of the loop (insulin) hits its positive end-stop.

Vim said...

Thanks anyway Nigel.

Nigel Kinbrum said...

I just corrected the link in my above post, in case you clicked on the old one. The new link shows the schematic for a NFB loop.

Vim said...

I´m also engineer, Nigel, and oscillators -for example- were a topic in my classes until recently.

Thanks anyway.
I´m just looking for some direct measurements on insulin that supports what you're saying.

Nigel Kinbrum said...

I don't know if there are any studies on the effect of large amounts of exogenous ketones on serum insulin level. Large amounts of GHB sends people to sleep, despite it being excitatory.

I know what happens, from NFB loop theory.

Have you had a rummage through PubMed?

Vim said...

No, I just trust that you did and there must be none.
Now, have a nice day.

Nigel Kinbrum said...

Never trust anyone! Having become tired of doing so many PubMed searches, I didn't do a search for the effect of large amounts of exogenous ketones on serum insulin level. Go on, you know you want to.

Have a good one, yourself!