Dr. Melissa Young details the evolution of technology in diabetes management from the perspective of a practicing endocrinologist.
Melissa Young, MD
Even though there are many other medications we can use for diabetes now that weren’t available a decade or two ago, many people still need to take insulin, and for patients with type 1 diabetes, insulin is life-sustaining.
“We’ve come a long way, baby,” as the old advertising slogan says. The methods of insulin administration, glucose monitoring, and data gathering are much different now than they were 2 or 3 decades ago.
Let’s start with insulin administration. I have older patients who balk at the idea of taking insulin because they remember their parent or aunt or uncle who had to use reusable glass syringes to draw insulin from a vial. These were later replaced with plastic syringes. No more need to resterilize the syringe, just use a brand new one every time!
Of course, drawing insulin into a syringe still requires significant dexterity and good up-close vision to ensure that the correct dose is drawn up—and there are still patients who prefer this method due to cost or habit. Meanwhile, every endocrinologist will tell you about that patient who was not doing it correctly and was drawing up air. No wonder the glucose levels never improved.
Along comes the insulin pen. This device allows patients to just dial to the number of units they need. This decreases the risk of giving an incorrect dose. It also made insulin more portable. Patients can carry a pen and few needles with them. No need to worry about keeping the vial refrigerated (although spare unused pens must be stored in the refrigerator) when they are out. No need to worry about dropping the vial and breaking it, losing days’ maybe weeks’ worth of medication. And the pen has evolved over time, too. The first few were refillable with replaceable cartridges. While those are still available, most insulins are now available in disposable pre-filled pens. There are also reusable pens that can tell you when you took your last dose and how many units you took. One can even be linked to an app that can calculate the insulin dose for the patient and estimate their insulin-on-board.
Even before the first insulin pen came out in 1985, the first insulin pump was developed. The first one was huge—about the size of a backpack—and certainly not convenient enough for everyday use. Over the last 3 or 4 decades, they have become smaller and more feature-packed. There are the traditional tubed-pumps and the “tubeless pump”. All pumps give a basal rate (a small amount of insulin that is continuously given throughout the day) and the patient can also make the pump deliver boluses of insulin for meals or to correct hyperglycemia. Since the infusion site generally only needs to be changed every 3 days, that means the patient can give him or herself 3, 4 even 10 doses of insulin through the day without having to puncture the skin more than once every 3 days. It gives patients more flexibility with meals and work.
The majority of patients who transition from multiple daily injections (MDI) do better on a pump. Now, there are even pumps that are integrated with continuous glucose sensors and two that can change the basal rate based on the data from the sensor. This decreases the risk of severe hypoglycemia and hyperglycemia.
This brings me to the continuous glucose sensor. Most patients tell me that one of the worst parts of managing their diabetes is checking their blood sugar. Although most patients don’t want to start taking injections such as insulin, once they’ve done it, they say the discomfort from doing an injection pales in comparison to the pain of having to prick their fingers. After all, fingertips are much more sensitive than the thigh or abdomen, and lancets have a larger diameter than insulin needles so that blood can come out.
Continuous glucose sensors allow patients to have nearly unlimited data about their glucose without the pain of frequent fingersticks. Patients are still advised to do periodic fingerstick testing either to calibrate the sensor or to confirm an abnormally high or low sensor reading, but they don’t have to do it as often as they have if they did not have a sensor.
Furthermore, many CGM systems have alerts. They can beep or vibrate to let the patient know that their glucose is dropping or rising too quickly before they have any symptoms of hypoglycemia or before their glucose is dangerously high. This is especially important in patients with hypoglycemia unawareness. A CGM can be a life-saver in someone who does not get the adrenergic warning symptoms of hypoglycemia.
As a physician, I recommend pumps and sensors to many of my patients for the benefits described above. In addition, the data that can be downloaded from the devices can help me fine tune their regimen. I look for patterns in their glucose and in their behavior. I can see how many carbs they have on a Friday night vs a Wednesday night and I can show the patient what happens when they have 100g of carbs versus 45g. I can see if their glucose is dropping in the middle of the night and can adjust their pump settings accordingly. I can see if they are missing doses on insulin, skipping meals, forgetting to turn the pump back on after they shower. Then we can work on correcting the behavior.
Insulin therapy and glucose monitoring has definitely changed the way diabetes can be managed and more improvements are sure to be developed in the next few years. The holy grail, of course, would be a device that both monitors glucose and delivers insulin with one site, and automatically delivers both basal and prandial insulin. That day is something many of my patients are looking forward to.