A1C increased

[wkndworrier]

I've been on Retatrutide for about 2 months at 4mg per week for the last month and am generally pleased with the fat loss and body composition changes (consistently about 1lb per week without much impact to strength).

I had some labs drawn and was surprised to see that my A1C had risen to 5.4 from 5.1 - which was the result of a few months on Tirzepitide, but only taking 1.5mg per week. My baseline has been 5.4 - 5.5 for the last decade, pre any GLP1 drug. My fasting glucose was 87, which is definitely lower than my typical baseline of mid-high 90s. Does the glucagon receptor agonist slightly raise blood sugar?

 

[diogenes]

Relative to tirzepatide, yes. Studies find A1C falls more on tirz than reta.

Glucagon mobilizes glycogen into glucose, so reta can increase blood glucose, hence higher A1C. But for most people on reta, the A1C decrease from reduced food (esp carb) intake means A1C falls overall. That seems not to be the case for you, but that isn't necessarily bad.

A1C 5.5 is normal, not a sign of metabolic problems. And small changes in A1C below 5.7 aren't necessarily instructive. You might ask your doc to measure your insulin sensitivity. That is a more robust measure of metabolic health than 0.3 points of A1C variation within normal range.

Visceral fat is itself harmful to metabolism. If your waist is shrinking to a healthier width, that is a good sign for your metabolism. Trust the process.

 

[BioDad]

I've been on Retatrutide for about 2 months at 4mg per week for the last month and am generally pleased with the fat loss and body composition changes (consistently about 1lb per week without much impact to strength).

I had some labs drawn and was surprised to see that my A1C had risen to 5.4 from 5.1 - which was the result of a few months on Tirzepitide, but only taking 1.5mg per week. My baseline has been 5.4 - 5.5 for the last decade, pre any GLP1 drug. My fasting glucose was 87, which is definitely lower than my typical baseline of mid-high 90s. Does the glucagon receptor agonist slightly raise blood sugar?

I agree with @diogenes that there is a process to it and over time, based on research and anecdotal evidence, you'll likely see those numbers normalize a bit to what they were.

As to your question, theoretically a glucagon receptor agonist would increase glucose levels, by driving glycogen breakdown and gluconeogenesis in the liver. However, also theoretically, with the added GLP-1 and GIP support simultaneously, might mitigate the effects.

I've looked at just about every study I could get my hands on regarding this, and only one study measured glucose-related markers as early as 12 weeks. The rest all waiting until 24 weeks, missing the opportunity to see if glucose initially goes up. All of the papers, however, we're on type 2 diabetics with an A1C in the 8's and fasting glucose in the 100's, so there was also a lot of room for improvement in those folks.