CWD Meets CGM.
"The problems are that they aren't accurate all the time and they don't replace fingersticks." She adjusted her shirt collar. "It's tough for insurance companies to get on board with that."
It's no surprise that I attended every CGM focus group offered at CWD. From discussions about government viewpoints with Arleen Pinkus of the FDA to debates about accuracy with Dr. Bruce Buckingham, I was tuned in and looking for ammo against my insurance company's repeated denials. (Acknowledgment of my second appeal arrived in the mail while I was away.)
"So you're telling us that we just need to slap a few sensors on some 65 plus diabetics and that will help turn the tide?" I asked.
She actually said, "Yes. That would do it."
Fortunately, the CGM session with Bruce Buckingham was far more informative and armed me with enough information for my third appeal letter. He was a warm and soft-spoken man who lead a 90 minute session about CGMs and how they can benefit the life of someone with diabetes.
"When I worked at the diabetes camps, they called me a pancreas, because my pancreas worked," he quipped to us, talking about the history of diabetes and explaining how physicians used to taste the urine of their patients to make a diagnosis. "The first pump was in 1978. The first common place meter was in 1980. I know - the pump was before the meter!"
Dr. Buckingham talked about how CGMs don't measure blood glucose, but instead measure the interstitial fluid. He told us that it takes about six minutes for the blood glucose to affect the interstitial fluid measurements, which helps explain how CGMs and glucose meters don't always match up with precision. He cited that the delay is more realistically a full eight minutes.
There was a lot of discussion about accuracy. From my almost 22 years of experience with type 1 diabetes, I'm convinced that every mg/dl result is a concrete one. It's been a tough mental hurdle, leaping from snapshots to trending. But Dr. Buckingham confirmed yet again that a CGM is a trending, and not a treatment, device. Any CGM result should be confirmed on a glucose meter before treating with food or insulin.
Another point he touched upon was that of sensor calibration. I test upwards of 15 times per day, so I was inclined to calibrate my sensor whenever I tested my blood sugar. "Calibrating when unsteady can cause the sensor to be biased," Dr. Buckingham said. If I test and my numbers are rapidly rising, I'm calibrating my sensor on the climb. That's going to throw off the accuracy for sure. Calibrating when steady (or at least steady-ish ... diabetes is never completely precise) helps retain the integrity of the sensor. But there is always a lag time with subcutaneous sensors, i.e. recovery from a low blood sugar may not be apparent on a sensor in a timely fashion.
All these technical details were well and good, but I wanted information on what made someone a good candidate for a CGM (particularly in the eyes of insurance companies). Dr. Buckingham provided a list of possible candidates:
- patients at a high A1c
- patients with a fear of hypoglycemia
- hypoglycemic unawareness
- patients on medications like pramlintide (Symlin) and exenatide
- patients who may wear the sensor intermittently to better understand their own diabetes
I saw myself on that list several times. Dr. Buckingham told the group about how a CGM can provide fantastic feedback that can really affect diabetes management decisions. He said that the immediacy of the feedback helps identify causality, meaning that we could see how different foods affect blood glucose levels, and that the data can be use to prevent or detect earlier extremes in glucose levels.
He did have some warnings, though. He warned about over-calibrating (as discussed before). He also warned against insulin stacking (taking small bolus after small bolus in efforts to correct highs). He also acknowledged that some of the alarms weren't effective, and that many PWDs slept through them. One tip he offered was to keep the CGM receiver in a glass on the bedside table, so that when it vibrates, the rattle in the glass helps wake you up.
"It doesn't work unless you wear it," he offered, adding that the sensor is a behavior modification tool and if you aren't ready to accept diabetes, you may not be ready to wear an extra device. According to Dr. Buckingham, a CGM can make someone feel vulnerable and defensive, with every number out there on display.
But then he said this: "A CGM can help you achieve a better A1C without increasing hypoglycemia." I thought about the lack of lows I've had in the past few months, and I was happy to not be crashing and burning in the middle of the night. But an elevated A1C also came along without those lows to tip the curve. I'm so hopeful that a CGM will help me gain better control of my diabetes without tossing my numbers down the well every few days.
I thought about how Chris said he feels safer when I wear it. My mom said the same thing. And I agree.
Come on, Insurance Companies. Get on board!!
Editor's Note: Do you want to join the fight for CGM coverage? Sign the CGM Denial Petition and Raise Your Voice!! Also, Dr. Bruce Buckingham is leading a chat about Continuous Glucose Monitors on DiabetesTalkFest tonight. Log in at 9 pm EST!