Doing away with the diabetes finger stick
A diagnosis of diabetes is always frightening, but in the past decade research and technology have made huge advances in helping people control their blood sugars. And more innovations are on the way, according to endocrinologist Mary Crowell, MD at the Endocrine Center of Cape Cod at Cape Cod Hospital.
“This is an amazing time to be working in diabetes medicine,” she said. “And looking forward from here, there are going to be so many changes in the next five to ten years.”
Anticipated advances include fully automated insulin pumps for those with Type 1 diabetes that require minimum input from users, better non-insulin medications for people with Type 2 diabetes, drugs to minimize cardiac events, and more targeted therapies to reduce risk and improve outcome.
Currently Dr. Crowell is excited about the Dexcom G6 continuous glucose monitoring system (CGM) for determining blood glucose levels. In March it received FDA approval for marketing and will be available next month. Dexcom CGMs have been around since 2006, but they were not previously designed as integrated systems to be used with other compatible devices until now. The G6 is the first Dexcom device that is factory calibrated and therefore does not require users to calibrate the device with finger stick blood glucose measurements.
“It is such a big deal for patients not to have to do those finger sticks,” Dr. Crowell said.
She explained that diabetics can’t add insulin unless they check their blood sugar first. Depending on the type and severity of diabetes, some patients have to do up to 10 finger sticks a day, which is time consuming and uncomfortable.
The Dexcom G6 is a patch device about the size of a thin quarter that you affix to your body. It has a tiny filament about the thickness of a hair that is inserted into the skin. It is entirely painless, Dr. Crowell said. The transmitter then continuously transmits glucose readings every five minutes to a receiver. The device comes with a receiver, but it is also wired with Bluetooth capability so the information can be transmitted to a smart phone.
One of the other nice features about the G6 is that the information can be shared. That is especially helpful to mothers of children with diabetes because they can keep track of the child’s blood sugar levels, even when they are apart, by simply checking in on their phone.
“It also has alarms so that you can set your high and your low alarm so it will ding or vibrate when your blood sugar gets too high or too low,” she said. “But what is really cool about this latest iteration is that it can predict if you’re going to go low. Rather than just alarming you when you are low, it can predict whether you’re going to get really low in the next 20 minutes based on the velocity of the glucose change, so you can do something about it, which is really awesome.”
Too High Or Too Low
For someone with diabetes, it is vital that their glucose numbers do not get too high or too low. The American Diabetes Association generally recommends a fasting blood sugar in the low 100s and a blood sugar between 150 and 180 two hours after a meal, but another change in diabetes management has been that those numbers can be tighter or looser depending on the individual patient, Dr. Crowell said.
That said, huge swings are always dangerous.
“Hypoglycemia occurs when your blood sugar drops low and there are different ranges for this,” she said. “As the blood sugar gets lower what happens is that the brain doesn’t get any glucose Your brain survives on glucose alone so you need to be continuously feeding it glucose. If that glucose level drops too low in the blood, brain cells will die.”
Hypoglycemia causes changes in mental status. People get confused, disoriented and have visual disturbances because the brain is starving. Ultimately it can lead to loss of consciousness, seizures and even death. Most people recognize that they don’t feel well when this occurs and can make corrections like drinking orange juice or soda, or eating a spoonful of sugar or honey.
Having high blood sugar is not as urgent in the individual moment, but long-term it causes both microvascular and macrovascular complications. The microvascular complications are damage to the blood vessels in the eyes, kidneys and nerves. That can lead to blindness, kidney damage and neuropathy. The macrovascular complications are damage to the larger blood vessels which can lead to heart attacks and strokes.
“We work very hard to prevent both high blood sugars and low blood sugars but unfortunately even our very best technology in pumps are really a crude replica of the pancreas which is an amazing organ,” she said. “We just don’t do it very well and that’s why CGMs are such helpful technology to improve on our ability to get the insulin dosing right.”
A Pump With A Brain
Most of the pump companies use Dexcom’s technology, but Medtronic is a pump company that has an integrated pump and CGM. Its latest version, the MiniMed 670G, uses a hybrid closed loop, which means that it fully integrates the blood sugars from the CGM and then makes decisions about insulin infusion based on the data from the CGM. It’s like a pump with a brain, Dr. Crowell said.
It automatically adjusts insulin every five minutes, which helps keep sugar levels in the target range so people have fewer lows and highs. It also stops insulin infusion up to 30 minutes before reaching the preset low and resumes insulin when sugar levels recover.
The biggest problem with both Dexcom and Medtronic systems is that they are expensive and insurance companies don’t always cover them, especially if you don’t have Type 1 diabetes or complex Type 2 diabetes, Dr. Crowell said.
The Dexcom G6 hasn’t been released yet so prices aren’t available, but their G5 version costs around $800 plus another $4,000 to $5,000 for an insulin pump. Replacement sensors cost about $350 a month. Medtronic’s integrated system costs between $5,000 and $8,000 with an additional couple of thousand dollars a year for replacement sensors.
Medicare has recently started covering these systems for diabetics who are doing sugar testing four or more times a day and giving themselves three or more insulin injections.
“These are not really meant for your average older Type 2 who might be taking two or three oral medications and maybe one dose of insulin,” Dr. Crowell said. “They are not available to those people, which is where the FreeStyle Libre comes in. I think that’s being pitched more towards a broader group of Type 2 diabetics who still want the advantages of the CGM without the cost.”
The FreeStyle Libre doesn’t have as many bells and whistles, but it does prevent finger sticks. Like the Dexcom systems, it uses a disposable patch that gets changed every 10 days. It measures blood sugars every 15 minutes and comes with a meter wand. When you put the meter next to the sensor patch, it will download the last eight hours of your blood sugar history. The meter costs about $70 and replacement patches cost about $120 a month.
“There is tons of work going on looking for cures for diabetes, but I think the emphasis of our current technologies are to manage it as best we can and try to mimic normal pancreatic function as best we can,” Dr. Crowell said.
“I’m constantly in awe of my patients and how well they cope with and manage this disease. This is why devices like the G6 are so great. Imagine if you had to do all of these things every day. It’s a huge advantage to have these technologies coming out that make things easier.”
[Image of the Dexcom G6 monitoring family, via: www.dexcom.com]