
Devices offer precision dosing for people with diabetes
Technology is making it easier for people with diabetes -- both Type 1 and Type 2 -- to receive a timely, correct amount of insulin. Explaining how pumps, monitors and other methods work or are being developed to keep blood sugar at a healthy level is Ruth Weinstock, MD, PhD, who also discusses the devices undergoing clinical trials at Upstate and what's on the horizon for diabetes treatment. She is a distinguished professor of medicine and the chief of endocrinology, diabetes and metabolism at Upstate. She is also a past president of medicine and science of the American Diabetes Association.
Transcript
Host Amber Smith: Upstate Medical University in Syracuse, New York, invites you to be The Informed Patient, with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith.
People who have Type 1 diabetes require insulin to keep their blood glucose levels where they need to be to stay healthy. Many with Type 2 diabetes also need insulin therapy. This involves injecting insulin through a syringe or an insulin pen multiple times a day, or using an insulin pump and monitoring of glucose levels. But there are new technologies available and being tested in clinical trials.
We'll hear about them from Dr. Ruth Weinstock. She's a distinguished professor of medicine, the chief of endocrinology, diabetes and metabolism at Upstate and past president of medicine and science of the American Diabetes Association.
Welcome back to "The Informed Patient," Dr. Weinstock.
Ruth Weinstock, MD, PhD: Thank you.
Host Amber Smith: So let's start with some definitions. What is an insulin pump, and how does it work?
Ruth Weinstock, MD, PhD: So an insulin pump is a different way of delivering insulin, instead of giving multiple injections a day, it's a way of giving insulin continuously.
So the pump has a cartridge filled with insulin, and then there's a catheter (hollow tube) that goes from the pump that the individual inserts just under their skin in the fatty tissue, which is the same place where they inject insulin. And that can stay there for three days or even up to a week, depending on the pump that they use. And then the pump infuses small doses of insulin every five minutes.
And the idea of that is to cover the needs of the individual to keep their blood sugar normal when they're not eating. And some people have different needs at different times of the day.
So the nice thing about the pump is it can change the amount it gives, depending on the person's needs. And then when they eat a meal, particularly eating carbohydrates, which turn to sugar and raise your blood sugar after you eat them, it can give what we call a bolus, or more insulin, through that same catheter to cover that rise in blood sugar that happens with the meal.
Host Amber Smith: So the patient doesn't really have to worry about this as much as they used to previously, before they had insulin.
Ruth Weinstock, MD, PhD: Well, it's still a lot of work. The individual still has to look at their blood sugars and still has to decide how much they're going to eat and what's the proper dose of insulin to give to cover that meal.
Now there's also a new technology called continuous glucose monitoring. It's been available now for several years, and that's another small device with a very thin filament that's placed in the arm or on the abdomen, and that measures your glucose or blood sugar levels, also every five minutes. And displays it either on your smartphone or on a reader that you can purchase along with the sensors.
And there are two main ones that are available, Dexcom and Libre, which people may have seen advertised on TV. They're nice because they show what your blood sugars are doing.
Host Amber Smith: Now, what is the difference between a tubeless pump, getting back to insulin pumps, a tubeless pump and other types of pumps?
Ruth Weinstock, MD, PhD: The original pumps and many that are available now, you could wear on your belt or put in your pocket, and then there's a long catheter that is used, the end of which is inserted either in your abdomen, but in the tissue right under the skin, where the insulin gets infused.
Some people, don't like wearing the pump. The tubing might get caught on things, or they may not have pockets in the clothes that they wear ... a variety of reasons.
Many people love these pumps, but there are some people for whom it's problematic. And so there's another pump that's tubeless, and basically what that is, it's a pot, it's a small insulin patch. You fill it with insulin, you apply it to the body. The catheter or needle goes right under the skin, the same place, but there's no tubing. So the insulin, instead of being in a pump that's not on your body, it's actually on your body, and it's controlled by either your smartphone or by a controller, another device that comes with it, so you can control it.
Host Amber Smith: So do these pumps measure blood glucose levels as well?
Ruth Weinstock, MD, PhD: So they don't, but many of them now do communicate with these continuous glucose monitors, and that has been one of the biggest advances for people who need to take multiple daily insulin injections, which is everyone with Type 1 diabetes and many with Type 2 diabetes.
So what we have now is people using a pump and a continuous glucose monitor in what's called a hybrid closed-loop, so there's some automated insulin delivery, and this is a big advance. So the pump receives glucose readings every five minutes and has an algorithm in it, a brain in it, that's very smart and can predict where your blood sugars are going to be in a half hour, depending on what the blood sugar is at that time and how fast it's changing and in what direction it's changing.
And so based on that, it delivers different amounts of insulin every five minutes, so small amounts of insulin. When you use a pump by itself, you program it to give a certain amount of insulin every five minutes. But in these new systems that are receiving this information from the continuous glucose monitors, the pump can make changes in how much insulin you need. So if your blood sugars are going down, it can suspend delivery for a few minutes, it can give less. They're going up, it can give a little bit more. So that's really has been a big advance.
And some of the more advanced ones, when you give an insulin bolus for the meal, it can give extra insulin if you under-bolus. If you didn't give quite enough insulin, and your blood sugars are going up, let's say you took another helping or decided to have some dessert, or whatever the issue is, and your blood sugars went a little too high, or you went to a Chinese restaurant and you didn't realize how much sugar was in the food, it can give you some ... what we call correction doses, some extra insulin, to try to keep you at your target.
Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith.
I'm talking with Dr. Ruth Weinstock, the chief of endocrinology, diabetes and metabolism at Upstate, and our subject is insulin delivery.
So these insulin pumps, the tubeless ones particularly, can a person wear that around the clock, when they go swimming, when they're in the shower? Or do they have to come off during those times?
Ruth Weinstock, MD, PhD: So actually all pumps are used around the clock. They have to be, particularly if you have Type 1 diabetes, so everybody wears them 24/7, whether it's tubeless or not. And the communication with the continuous glucose monitors occurs in both the tubeless and the pumps with tubing. So that isn't different.
Now, you can shower with the tubeless one, obviously without taking the device off, but with the ones that have tubing, it's not difficult either because there is a way to detach the catheter from your body for a shower without taking it out of your body. And you can shower, you can swim, and then you can just reconnect afterwards.
Now, the automated insulin delivery that you described, can that be used in people who have trouble remembering to take mealtime insulin injections? That's a great question. What we find is that these devices work best when people do bolus for meals. But even if they forget, they still are helpful. Your blood sugar will not go as high. Your blood sugar control won't be perfect, but I have patients who are using these, who have, for example, cognitive impairment and have difficulty remembering how to bolus, or there are some people who just forget sometimes, but at least the pumps will give some correction doses so that it wouldn't be as high as it otherwise would.
They're not perfect yet. However, there are clinical trials now, and there are advances of a total closed-loop system, meaning that you wouldn't have to bolus at all. The pump and sensor do everything for you, and hopefully those systems, with even more sophisticated algorithms, brains, in them will be able to control blood sugars, and the individual won't have to worry about bolusing and greatly decrease the burden of having diabetes.
One of the great things about these automated systems is that they do reduce time that your blood sugar goes too low, hypoglycemia, because it suspends insulin delivery if it senses that you're going to go too low, and people have a much greater time in the normal range.
Host Amber Smith: You keep saying "the bolus"? What is a bolus?
Ruth Weinstock, MD, PhD: The bolus is when you tell the pump to give extra insulin because you're about to eat.
Host Amber Smith: I see.
Ruth Weinstock, MD, PhD: So you can either tell it how much you're going to eat, how many carbohydrates, or if it's a small, medium or large meal, and we program in how much insulin is needed for that.
So bolus is basically extra insulin. The basal (base rate) is the every five minutes to keep you normal when you're not eating.
Host Amber Smith: I see. Can you tell us about inhaled insulin? Does it work as well as the injectable kind?
Ruth Weinstock, MD, PhD: Inhaled insulin has been available for a while. It's a very rapidly acting insulin. So if you have Type 1 diabetes, you still need to take a long-acting insulin if you're using inhaled insulin. So the long-acting insulin, the idea would be, that would keep your blood sugar normal when you're not eating, and the inhaled insulin, you would take when you're about to eat.
It works faster than the injectable insulin and doesn't last quite as long. Some people find it very helpful. It's only available in certain doses, and you can't use it if you have any chronic lung disease or asthma, so there are some restrictions. And some people do develop a cough or wheezing. You have to monitor pulmonary function when you use that.
So there are some limitations. So for some people it works really well, and for others, the injectable works better. But you can't use the automation with that. So that's a way of instead of an injection, for meals.
Host Amber Smith: Well, what about oral insulin?
Are there pills that you can take?
Ruth Weinstock, MD, PhD: Not yet. The absorption of the oral insulin can be erratic. And the dosing is problematic. So, so far, it has not worked as well as injectable or inhaled, and it's not yet commercially available.
Host Amber Smith: Are there transdermal insulins where it would soak in through the skin?
Ruth Weinstock, MD, PhD: So actually, no. Right now, the only insulins are injectable or the inhaled. Those are the only ones that are available right now. And as I said, the inhaled is only for fast acting, for meals. Or if you are very high, and you want to bring it down quickly.
Host Amber Smith: What clinical trials are you doing with new insulin delivery devices?
Ruth Weinstock, MD, PhD: We do a lot of clinical trials here at Upstate. Actually, we have about 20 research, clinical research, projects related to diabetes, so we're constantly testing new devices, new pumps, where they have improved the technology. They're constantly improving the technology, making the algorithms better so that they correct people's blood sugars more accurately and more automatically.
So we have trials with new devices that are doing that, new insulin pumps. We're also doing a trial with pumps and Type 2 diabetes. So traditionally, insurance has only paid for insulin pump therapy in Type 1 diabetes, but many people with Type 2 diabetes also require insulin therapy. And so we are finishing a trial now, and we have a couple more that we're going to be starting, with Type 2 diabetes using automated insulin delivery, where the individual wears the sensor and the pump. And there's the automation that I talked about, and most people do extremely well, so we're hoping that the results of these clinical trials will make it such that insurers will be willing to pay for this technology in Type 2 diabetes for people who need it.
Host Amber Smith: What new developments are you most excited about?
Ruth Weinstock, MD, PhD: So I'm really excited about the new pumps and sensors and making it totally automated, so the individual doesn't have to do anything. Well, they'll always have to do something, but they put the pump on, they put the sensor on, and then they don't have to think about it. That would greatly reduce the burden and improve blood sugar control for people with diabetes.
But that's not a cure. So there are new approaches that I find extremely exciting that hopefully we will see more in the future. And we are just starting to do research in this area right now at Upstate, which is regenerating islets. So the islets are the part of the pancreas that has the cells that make insulin and control blood sugar.
And there are ways now to take stem cells like from skin cells or other cells, not embryos -- it doesn't have to be embryos, but it could be other cells -- and actually generate new organs and islets. So we are, collaborating, with groups and we have investigators here as well who are working on this technology.
So someone with Type 2 diabetes who needs insulin, if we could take some of their skin cells and generate, make islets and give it back to them, that would be a cure, and that would be fantastic.
So all these technologies have reduced the burden and help people with diabetes avoid complications, but they're not cures.
The cure would be either transplant or actually regenerating islets, but making islets and giving it to people where they don't need to take immunotherapy, immunosuppressants, that's the goal. With transplants now you have to take drugs that have some side effects, potentially.
So if we could make islets that you don't need to take those drugs, that would be just wonderful for people with diabetes.
Host Amber Smith: If you're working from the person's stem cells to create the regenerative islets, would that eliminate the need for medications for anti-rejection?
Ruth Weinstock, MD, PhD: Well, we hope that it can be developed in such a way that that could happen.
There are also people who are looking at encapsulating the islets with substances that have little pores that the insulin and glucose can go in and out of, but the immune system can't attack the islets. So there is a lot of exciting research going on.
We also have clinical trials going on in people with very early-stage Type 1 diabetes, giving treatment that can hopefully prevent the progression.
A lot of exciting trials. If, anyone who's listening is interested in learning about trials, they can give us a call at 315-464-9012, and we can give you more information, or 315-464-9008.
Host Amber Smith: I appreciate you making time for this interview, Dr. Weinstock.
Ruth Weinstock, MD, PhD: Thank you.
Host Amber Smith: My guest has been Dr. Ruth Weinstock. She's a distinguished professor of medicine, the chief of endocrinology, diabetes and metabolism at Upstate and past president of medicine and science of the American Diabetes Association.
"The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe.
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