Initiating Insulin in Type 2 Diabetes

Serge Jabbour, MD, and Dhiren Patel, PharmD, discuss the need for adding insulin therapy to a regimen for patients with type 2 diabetes mellitus.

Serge Jabbour, MD: The question I get all the time is when to start insulin in a patient with type 2 diabetes. We typically follow the ACE guidelines. The guidelines say any patient with type 2 diabetes with an A1C level of more than 9% should be considered for insulin. Now, they say, “should be considered.” It’s not that they must. The only time I would say it’s a must is if I see a patient with type 2 diabetes in a catabolic state, no matter what the A1C level is. A1C could be at 9.5%, 10%, or 12%, but they are losing weight at the same time without trying to lose weight. That means they are burning fat and muscle because if you lack insulin, that has a catabolic effect.

When they are losing weight in the face of high A1C, then we have to start insulin right away if they are not in a catabolic state. It depends on every patient. It depends on how many drugs they’re on already; it depends on how high the A1C level is; it depends on if it’s high fasting or high postprandial, if both are high; and it depends on if we can maybe use other medications before we start insulin.

I’ll give you a quick example. If you have a patient who’s on metformin and SU (sulfonylurea), but they have impaired kidney function, that means we cannot use SGLT2 inhibitors. They had gastroparesis. We cannot use a GLP1 receptor agonist. Their A1C level is 8.8%. Then my best choice is to add a basal insulin. So, it depends on every case. It’s not a standard, and it’s more based on each individual.

Dhiren Patel, PharmD: When it comes to insulin therapy, there are a lot of preconceived notions from the patient perspective. Many think that if I’m starting insulin, my condition has progressed to this point where it’s uncontrolled and I need to go on insulin. And in some cases, it’s not that. You want early, aggressive, tight control in someone who has an elevated blood sugar or elevated A1C level greater than 9% or 10% where it’s actually indicated and recommended for a variety of reasons. But again, from the patient’s standpoint, it might signal disease progression.

Other perceived barriers are that it’s going to cause weight gain or it’s going to cause low blood sugar. These are the things that they’ve heard with insulin. And then, the other one is regarding the complications of it. A patient who might be on insulin could have heard from their neighbor or family member that insulin was started, initiated, and then subsequent complications occurred. And it wasn’t because of the insulin, it was because the disease was uncontrolled for such a long time that these complications set in. But they can’t discern if that was the insulin or it was disease progression. Because of that, patients will associate certain complications with insulin when, actually, it’s used to prevent those complications from happening. Those are the issues that I probably see most often.

Serge Jabbour, MD: We decide to start insulin after convincing patients that it’s based on normal physiology. We all secrete insulin and at some point, when you have type 2 diabetes for a long time, your beta cells will completely burn out. So, it’s time to start insulin. And when you start insulin, it always works as long as you picked the right insulin combination—it could be basal—you pick the right dose, and you titrate the insulin correctly in patients.

Now, there are certain patients, typically up to 5% of them, who may be severely insulin resistant, which is defined as needing more than 200 units of insulin per day. That’s when we can go to the more concentrated insulins, like U-500, which would work in these patients. But even in those who need less than 200 units of insulin per day, we can still use other concentrated insulins—U-200, U-300—because one frustrating thing for most of these patients is the number of injections they have to do on a daily basis.