and Sensor-Augmented Pumps
A CGM is a device that can give information in real time to help with diabetes management decisions. With some devices, the pump and the CGM work together in a single system. The expanded availability and use of CGMs can be partially credited to clinical research into this new device. Some of the studies looked at the use of insulin pump therapy integrated with a CGM. This type of therapy is often called sensor-augmented pump therapy, or SAPT. Other studies looked at the benefits of individuals using a CGM either with an insulin pump or with MDI.
The Juvenile Diabetes Research Foundation (JDRF) sponsored one of the largest studies ever done on CGMs. The study included 322 adults and children who were receiving intensive therapy for type 1 diabetes (either with an insulin pump or MDI). After six months, adults showed improved blood glucose control. A subset of children and adults whose A1C values were less than 7.0% at the beginning of the study was also analyzed. In this group of individuals, low blood glucose (hypoglycemia) was less frequent, time spent out of the target blood glucose range was shorter, and average A1C levels were still excellent. The benefits of CGM go beyond just the clinical benefits and improved glucose control: the adults and parents of children who used CGM were also pleased with this method of treatment.
In 2010, the results of the STAR 3 study were published in the New England Journal of Medicine. The STAR 3 study is the largest study of its kind, and it examined the benefits of SAPT in people with type 1 diabetes comparing it against MDI. The study demonstrated that in both children and adults with inadequately controlled type 1 diabetes, SAPT improved A1C levels. A1C levels were 0.6% lower than those in the MDI group. Also, a greater number of individuals reached their A1C target levels.
Once the STAR 3 study was completed, the patients receiving MDI in the first year of the study were placed on SAPT for six months. They were compared with the people who received SAPT during the first year of the study and who continued on SAPT for the same six-month period. There was a significant and sustained decrease in A1C levels in the children and adults who went from MDI to SAPT for the final six months of the study.
One of the most important lessons we’ve learned from all of the clinical studies done with SAPT is that the biggest treatment benefit is seen in those individuals who use CGM on a consistent and sustained basis. The greatest improvement in blood glucose control was seen in individuals who wore the CGM for more than 60% of the time. This was true for children, adolescents, and adults.
Guidelines
In 2005, the American Diabetes Association published its guidelines for the management of diabetes in children: “The Care of Children and Adolescents with Type 1 Diabetes.” Here are a few of the key items from those guidelines:
• Insulin pump use is widespread in children with diabetes.
• There is no correct age at which to initiate insulin pump therapy, so treatment plans should consider the needs of the patient as well as those of the family to determine who is an appropriate candidate for an insulin pump and when he or she should begin pump therapy.
• The support of adults at home and at school is essential for the child’s success with all diabetes management, but especially with pump therapy.
Other medical associations have published recommendations. The International Society for Pediatric and Adolescent Diabetes published theirs in 2009. That guideline explains that insulin pump therapy is the best way to imitate how a human body without diabetes provides insulin. The American Association of Clinical Endocrinologists has a consensus statement that discusses the broad groups of patients with type 1 and type 2 diabetes who may benefit from insulin pump therapy.
CHAPTER REVIEW
• Appreciate how far you have come since your original diagnosis. You have learned so much about diabetes management, the tasks you need to perform, and ways to better control your glucose levels.
• The concepts of basal and bolus insulin delivery are the keys to pump therapy. Either method can be adjusted throughout the day and night to improve glucose control.
• Transitioning from MDI to pump therapy means you go from taking two
(or maybe even more) kinds of insulin to one—only rapid-acting insulin.
• You should know your blood glucose and A1C targets. You adjust your insulin doses, food intake, and activity levels to reach your glucose targets throughout the day and night. At your diabetes visits, find out your A1C so you can know if you have achieved your goal.
• There is a lot of evidence from scientific studies that shows the benefits of insulin pump therapy. Pumps reduce hypoglycemia, improve A1C levels, improve quality of life, and reduce daily insulin dosages. CGM has the ability to further improve diabetes care, particularly when used most of the time.
CHAPTER 2 AN OVERVIEW OF INSULIN PUMPS
IN THIS CHAPTER
• What Exactly Is an Insulin Pump?
• What Makes You a Good Pump Candidate?
WHAT EXACTLY IS AN INSULIN PUMP?
Simply put, an insulin pump is a device to deliver insulin. It is a small mechanical device that is worn externally. It is prescribed by your physician, and your diabetes team will determine your starting doses. You will need to learn how to program the pump, and then you will be responsible for telling it how much insulin to give you. You program it to provide both basal (the background insulin) and bolus
insulin (for meals and correction doses). A computer in the pump regulates the flow of insulin into the body. An insulin pump eliminates the use of daily injections and uses only rapid-acting insulin both for the basal rates and for boluses.
Durable Pumps and Patch Pumps
Durable insulin pumps are about the size of a deck of cards and can come in a variety of types and colors. Most pumps are connected to the body by tubing. This tubing runs from a reservoir filled with insulin in the pump to an infusion set, which is secured to your body. The infusion set is made up of a small 6–9 mm (less than ½ inch) soft plastic cannula that is inserted under the skin. It is inserted by a needle, which is then removed. The cannula can also be a very small steel needle that is easily inserted under the skin. The computer in the pump controls a motor that that dispenses the insulin in tiny amounts. The insulin flows from the reservoir into the tubing and then through the cannula into the tissue under the skin. There is a display screen on the pump, and buttons to program insulin delivery.
Patch pumps are attached directly to the body. They do not have an infusion set or tubing. The insulin reservoir is inside the patch, and you fill the reservoir before placing the patch
