Smart Tips for Insulin Pump Users
You know the basics: Pumps automatically deliver rapid-acting insulin around the clock, plus bolus doses you select at mealtime and to correct high blood glucose levels. But you may be unaware of the features that can dramatically improve your diabetes management. Not to worry—here’s what to know in order to get the most out of your insulin pump.
Insulin pumps provide a constant infusion of rapid-acting insulin (called a basal rate) to control blood glucose levels throughout the day.
Multiple Basal Programs
Make your pump work with your lifestyle and blood glucose trends by programming more than one basal rate to run throughout the day. For instance, you may want to program a higher rate (that’s more insulin) for the early morning, when wake-up hormone levels (known as the dawn phenomenon) might raise your blood glucose. But you may also program a lower basal rate (for less insulin) for afternoons, when you’re more sensitive to insulin. Work with your diabetes care team to adjust your basal rates to reflect your lifestyle and glucose trends throughout the day.
Temporary Basal Rates
There are a host of factors that affect your blood glucose, including food and drink, exercise, medication, and illness. To prevent high and/or low blood glucose in the face of short-term changes, your insulin dosing needs to be adjusted. That’s where a temporary basal rate comes in: You can increase or decrease your basal rate by a certain percentage for a programmed number of hours.
Consider setting a higher rate if you’re stressed out, menstruating, or receiving corticosteroids of any kind (injections, pills, etc.). You might need a lower rate if you’re exercising or sick and unable to eat much (your body will need some insulin, however).
For hypoglycemia prevention, Medtronic’s MiniMed 530G and 630G pumps automatically stop insulin delivery for up to two hours when your glucose level reaches a preset low threshold and you don’t respond to an alert. It’s particularly valuable for those who experience hypoglycemia multiple times during the night and for those who have hypoglycemia unawareness—the inability to feel the symptoms of low blood glucose.
In addition to enhancing diabetes management through basal insulin delivery, pumps also provide ways to optimize blood glucose levels related to mealtime and correction doses—referred to as bolus insulin delivery.
Extended, or “Square Wave,” Bolus
Meals high in protein, fat, and fiber take longer to raise blood glucose. Deliver a standard bolus with such a meal, and the immediate insulin dose could cause low blood glucose. The most effective mealtime bolus for foods high in protein, fat, and/or fiber will begin lowering blood glucose an hour or more after eating. That’s where an extended bolus comes in. It’s also a good option for people with gastroparesis, a disorder that delays stomach emptying and causes foods to be absorbed slowly.
Dual Wave Bolus
A dual wave bolus combines the immediate and extended bolus. It’s helpful when eating foods that consist of high fat and/or protein paired with simple carbohydrates. Take, for instance, a hamburger: The early burst of insulin provides immediate coverage for the initial carb from the bun, and the delayed bolus covers any carb slowed down by the fat and protein in the burger.
Insulin Sensitivity Factor
The insulin sensitivity factor represents the number of points your glucose drops with 1 unit of insulin—essentially how sensitive you are to insulin. Your health care provider can help you calculate an insulin sensitivity factor, which you can enter into your pump. The pump uses the factor to calculate bolus insulin when you correct for high blood glucose.
Input insulin duration into your pump, and the device will use it to calculate how long bolused insulin will work to lower your blood glucose. This feature prevents insulin “stacking” due to correction doses that are given too frequently. Because rapid-acting insulin lasts three to four hours, the insulin duration setting limits additional correction doses given too soon after an initial correction bolus.
The insulin-to-carb ratio describes how many grams of carbohydrate you expect to be covered by 1 unit of rapid-acting insulin. Your diabetes care team can help you calculate your initial insulin-to-carb ratio, which you’ll fine-tune together over time. Your pump can use your insulin-to-carb ratio to decide how many units of insulin you should take based on the amount of carbohydrate grams you tell the pump that you plan to eat.
Deena Adimoolam, MD, is an assistant professor of endocrinology at the Icahn School of Medicine at Mount Sinai in New York.
Patch vs. Pump
If you’re looking to ditch the multiple daily injections but don’t need the advanced features pumps provide, check out Valeritas’s V-Go. The device, created specifically for people with type 2 diabetes, sticks to the body and automatically delivers basal insulin. You can also deliver boluses with the push of a button.
Size and Weight: 2.4 x 1.3 x 0.5 in. 0.7 to 1.8 oz. filled, depending on units of insulin used
Reservoir: V-Go 20: 20 units basal over 24 hours; 36 units bolus in 2-unit increments; 56 units total V-Go 30: 30 units basal over 24 hours; 36 units bolus in 2-unit increments; 66 units total V-Go 40: 40 units basal over 24 hours; 36 units bolus in 2-unit increments; 76 units total
Infusion Set: Does not use tubing. Comes with a built-in, 30-gauge, pivoting stainless steel needle with a 90° insertion angle.
Battery: No battery; uses mechanical power source
Details: Specifically designed for use by adults with type 2 diabetes. Unlike other devices, the V-Go delivers bolus insulin with button presses, not electronics. Each disposable device is used for 24 hours, after which time users attach a new V-Go. Device may be submerged to a depth of 3 feet, 3 inches, for 24 hours, so there’s no need to remove the patch while swimming or bathing. Does not work with data management software, and doesn’t connect with any meters or CGMs.