The continuous glucose monitor (CGM) has been hailed as vital technology for good blood sugar management in type 1 diabetes. But although it could provide similar benefits to people with type 2 diabetes, the expensive technology is not yet widely available for type 2 patients.
Enthusiasm is growing for the use of CGMs for patients with type 2 diabetes, but some experts remain skeptical. And some of the critical decision-makers still need to be convinced before access will really expand.
Patients with type 2 diabetes typically experience fewer intense and unpredictable blood sugar swings than those with type 1. Only a minority of patients with type 2 diabetes have been prescribed insulin, and only a minority of them use rapid-acting insulin multiple times a day, the way that patients with type 1 require.
Many experts are eager to give patients with type 2 a new tool to help manage their condition. And nothing would make CGM manufacturers happier than to sell their products to the type 2 market; for every patient with type 1 diabetes, there are about 20 potential customers with type 2. But scientists have yet to make the case that the CGM is so helpful to patients with type 2 diabetes that it justifies its high price.
So far, the American Diabetes Association has only recommended CGMs for patients with type 2 diabetes that are on “intensive” insulin regimens – patients that are using insulin pumps or multiple daily injections to control blood sugar levels aggressively.
It certainly makes sense for patients on intensive regimens to get the earliest access to the tech. Frequent blood sugar readings allow these patients to dose insulin for meals, exercise, and corrections far more precisely. The alarm function can be a literal lifesaver in the event of low blood sugars.
However, millions of patients with type 2 diabetes use only basal insulin, and millions more do not require insulin at all. They may not need to make multiple insulin dosing decisions every day, and may have a less critical need for low blood sugar alarms, but the device could still play a huge role in improving their glucose management.
Many people with type 2 diabetes are eager to use a CGM but cannot pay for it out-of-pocket. Some find themselves in the disheartening circumstance of knowing that they can only access this valuable technology if their control gets worse.
But a new study may help change this situation.
The MOBILE Study
Dexcom, the manufacturer of the popular G6 CGM system, recently unveiled the results of a randomized clinical trial pitting its continuous glucose monitors against traditional blood sugar meters. The studies were published in the medical journal JAMA and presented at the recent Advanced Technologies & Treatments For Diabetes (ATTD 2021) conference.
The MOBILE study looked at 175 adults with “poorly controlled” type 2 diabetes who used basal insulin but had not been prescribed multiple injections of mealtime insulin. The participants began the trial with an A1c between 7.8% and 11.5%. They were randomized into two groups: those given CGMs, and those given blood sugar meters.
After eight months, both groups had improved A1c’s, but the group using CGMs improved much more: −1.1% vs. −0.6%. On average, the CGM users spent about four more hours in range and four fewer with very high glucose (>250 mg/dL).
Those improvements appeared to apply across the board. When researchers split the study group into different subsections based on age, education level, or “diabetes numeracy,” the group using the CGM always had significantly better results than the group using fingersticks.
A second study was published in the same edition of JAMA; this one observed the outcomes of patients that began using Dexcom CGMs in real life (without any intervention by the researchers). Patients with type 2 who initiated CGM use were overwhelmingly likely (97%) to be using intensive insulin regimens, just as the guidelines recommend.
The results? Type 2 CGM users improved from an average 8.2% A1c to 7.64%, an even larger improvement than patients with type 1 enjoyed in the same study. They also experienced significantly less hypoglycemia than they had previously.
Dexcom, unsurprisingly, was ebullient, describing the publication of the two studies as “a pivotal moment in diabetes care innovation.”
Not everyone agrees that CGMs should be prescribed to more patients with type 2 diabetes. In March, Kaiser Health News argued that there is actually very little evidence that the technology does much good for most patients in the type 2 community.
The writer noted that the small number of studies of the CGM’s efficacy in type 2 diabetes have so far come up with conflicting results; several find little benefit. And while the data from the two new Dexcom studies wasn’t yet available, it might be wise not to take the results of industry-sponsored science at face value. Several of the older studies that found good results for continuous glucose monitoring were similarly organized by CGM manufacturers, including Dexcom.
Dr. Katrina Donahue, director of research at the University of North Carolina Department of Family Medicine, was one skeptical expert quoted in the article: “I don’t see the extra value with CGM in this population with current evidence we have… I’m not sure if more technology is the right answer for most patients.”
Price is going to be a big issue. Dexcom, Abbott, and any other competitors not only have to convince patients and doctors that the CGM is can help type 2 diabetes. They also have to convince insurance companies that it’s worth paying for.
That might be a tough job. Many CGMs users are already acutely aware of how expensive the product can be. If the benefits to patients with Type 2 that do not require intensive insulin treatment are less dramatic, insurance companies will be less enthusiastic about covering the system.
Some doctors agree. Dr. Silvio Inzucchi, director of the Yale Diabetes Center, was quoted by Kaiser Health News: “The price point for these devices is not justifiable for routine use for the average person with Type 2 diabetes.”
Short-Term CGM Use
Interestingly, the results of the two studies suggest that the improvements in glycemic control were not the result of increased insulin use but improved patient engagement. The CGM can serve as a constant gentle reminder of the importance of glucose management. Hopefully, the thinking goes, CGM users are more likely to make good eating or exercise decisions.
That finding might help support the advance of temporary CGM use for patients with diabetes. If the CGM works primarily by informing its user about the glycemic impact of different lifestyle decisions, maybe people could benefit from only a week or two of CGM use. They might learn lessons that they could put use to improve their glucose management even after ceasing to use the device.
The temporary CGM has long been rumored as the next big step for patients with type 2. Some healthcare providers already have CGMs that they will loan to patients for short-term rentals, and Dexcom has recently made its CGM available on a trial basis through its Hello Dexcom initiative.
JAMA simultaneously published an editorial arguing for expanding the use of CGMs for patients with Type 2 diabetes. Authored by doctors Monica Peek and Celeste Thomas of the University of Chicago, the letter calls for “important policy changes in Medicare eligibility to CGM for type 2 diabetes and institutional changes that promote its use in primary care.”
The writers also noted that patients “from racial and ethnic minority populations, those in low-income groups, and other socially marginalized groups are disproportionately affected by type 2 diabetes,” and that improved access to CGMs could especially help the most vulnerable diabetes patients.
The MOBILE Study is just one step, but perhaps a significant one, in widening access to the CGM for the type 2 community. Advocates will hope that such data will convince the diabetes authorities, especially the American Diabetes Association, to expand their recommendations.