Glucagon me… n=1 experiments with microbolusing Glucagon part 1: setting a baseline

Everyone with type 1 is taught that the big orange plastic box that we’re supposed to keep in the fridge is for emergencies only and should only be used by someone else, when we’re unable to help ourselves, due to severe hypoglycemia.

What a long sentence to start with, and is the hypothesis correct?

A little background

Glucagon is a hormone that is produced by the alpha cells and is critical in maintaining glucose homeostasis. It works with the many endocrine hormones to manage glucose, speed of food transit and liver function, amongst many other things.

Perhaps the most prominent research into Glucagon was undertaken by Roger Unger, who postulated, amongst other things, that Type 1 diabetes is characterized by an excess of glucagon, as there is no mechanism by which it is constrained, due to the lack of beta cells. You could think of this as the liver being a glucose tap, which can never be turned off.

But what of this, and why does it matter here?

There are two parts to this question. The first is that constant glucagon release requires more exogenous insulin to manage it. The second is that if we can cause the liver to release additional glucose from glycogen, then there’s a counter-reaction, whereby the liver needs to reabsorb glucose and convert it back to glycogen.

In theory, if we can counter the first of these, and cause the second, we could increase insulin sensitivity.

Managing ongoing glucagon release

There has been some research undertaken into methods to reduce glucagon production (and increase beta cell mass, but we’re less concerned with that here). It uses a triple drug approach, using proton pump inhibitors (PPI), GABA and DPP4 inhibitors.

What’s the purpose of these? According to the patent:

DPP-4 inhibitors (DPP-4i) block the activity of the DPP-4 enzyme, which leads to an increase in both concentration and the duration of action of GLP-1 and GIP. They are taken orally and provide a healthy physiological level of incretins in the blood.

A critically important feature of the effect of GLP-1 on the function of p and a cells is its glucose-dependent nature. This means that the GLP-1 stimulates insulin secretion and, on the other hand, suppresses the production of glucagon only under conditions of hyperglycemia. Once plasma glucose drops to a regular level, the effects above of GLP-1 subside, making it a reliable physiological mechanism for preventing the development of a hypoglycemic state.

GABA (Gamma Amino Butyric Acid) affects both β and α-cells, their functions and the viability of the pancreas as a whole. This substance is widely used as a food supplement. In α-cells, GABA induces hyperpolarisation of the membrane and suppresses glucagon, whereas in β-cells it induces membrane depolarization and increases insulin secretion. Also, GABA has a multi-directional positive effect on β-cells, which includes the stimulation of cell proliferation and anti-apoptosis, thus making it an attractive option for complex treatment of diabetes.

Proton pump inhibitors inhibit Na+/K+-ATPase (proton pump) on the apical membrane of parietal cells of the gastric mucosa and ensure the achievement of clinical, endoscopic remission in all acid-dependent diseases, including those requiring prolonged or continuous therapy. For an extended period during the day, they maintain pH values in the stomach within limits favorable for the healing of stomach or duodenal ulcers. The general effect of the pharmacological action of the drugs of this group is the increase of Gastrin in the blood and the pancreatic tissue. Gastrin is a natural stimulant for the recovery (regeneration) of pancreatic cells.

US Patent Application for Combination treatment for the regenerative therapy of type 1 diabetes mellitus patients Patent Application (Application #20190240218)

It’s worth noting that commentary regarding the effect of GABA within the pancreas. It plays a key part in glucose homeostasis and is also yet another “missing” secretion from the beta cells that those with T1D have to manage without.

Neither GABA nor DPP4 inhibitors are available in the UK without prescription, and the intention of the PPI is to attempt to retain beta cell mass, so I started with a GABA receptor agonist, L-Theanine, to, in theory, try and reduce the effects of the ongoing glucagon production by encouraging glucagon receptors on my alpha cells to react more to whatever GABA was circulating.

Did it work? The next two images show the TIR data for February (without L-Theanine supplement) and March (with supplement). I’d argue that lifestyle variability in March was lower than during February, so I’m not sure that the two datasets show anything significant.

Glucagon administration

Everyone who is using insulin should have a Glucagon kit. My last one was significantly out of date, so I replaced it and thought I’d see if it still worked.

Does expired Glucagon still work?

9 months out of date, and 3 years since it saw a fridge, it did. In many ways that’s not a huge surprise. Dehydrated glucagon and distilled water really shouldn’t be affected by too much, however, manufacturers need to provide a guarantee of efficiency, especially as a treatment of last resort, so I shouldn’t be that surprised.

With step one out of the way (functioning Glucagon), the next “macro” question was “how long would the made up GlucaGen kit last?

Reconstituted Glucagon lifespan

Again, it was designed as a one shot use, so there are no claims about how long it would last. The various teams that have used it in dual hormone AID systems have commented that it needed changing every day. A brief chat with the team behind Inreda at ATTD suggested that it might last a bit longer, so I was curious to find out.

This process wasn’t very scientific and entailed dosing Glucagon when the algorithm required I do so, and seeing if it had any effect.

On days one through three, it did as I expected, and acted counter to insulin on board, more of which later.

On day four, it did pretty much nothing.

Repeated with a second, within date, kit, almost exactly the same duration was observed. After three days, there was no effect.

With this in mind, you could, in theory at least, use 1ml of reconstituted glucagon in a pump for 3 days, which would work nicely for an Omnipod, for example.

How much Glucagon to dose?

This is a difficult one. All those who have been given a full 1mg of glucagon in its 1ml of water will recall the nausea and perhaps sickness as the after effects.

With this in mind, I wanted to start at a lower dose, and see a) if it worked and b) if it didn’t make me feel ill.

Dosing was done with a standard 0.3ml insulin syringe.

I started with 0.05 milligrammes as the initial standard dose, which seemed like it should provide a reasonable amount of use from one pack. I hoped it wouldn’t produce sickness and could also allow some level of dose titration for effect of increasing blood glucose levels. It also provided a standard value for trying to relate effects to insulin on board.

0.05mg, as anticipated, did not result in any nauseating side effects. Increasing the dose to 0.1mg and 0.15mg, on the other hand, did induce a mild sense of nausea. Fortunately, 0.05mg (5iu) also indices a reasonable counter hypoglycemic effect, so larger shots probably aren’t required.

Each individual would need to see for themselves what dose worked for them, but mine was clearly obvious.

Baseline for what?

Within AndroidAPS, the algorithm could be adapted to use the “Carbs required” signal to trigger a dose of glucagon. This would require an additional pump to be connected to the system, with zero basal rate and dosing only glucagon boluses. This isn’t beyond the realms of imagination and should be feasible.

But there’s little to no information about using microbolusing of glucagon in the public domain.

The experiment here was to understand what the relationship between insulin on board, glucagon dose and glucose rise looks like, in an n=1 experiment without a huge amount of data.

And also to see if there was anything else that needed consideration as a result of this.

The answer to above questions is that there does seem to be a relationship, and that some of it is perhaps more complex than we’d think. In general as a population, we probably don’t understand fully the effects of exogenous glucagon, even though there are certainly those who have a much better idea (Inreda, Betabionics).

But thats for the next article

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