In this week’s issue of The Savvy Diabetic:
- Dexcom’s FDA Warning Letter & Dexcom’s Response Claims No Wrongdoing
- CGM MARD Wars, with Values without Context
- Looking for Glucose Patterns – See Trends & Possible Adjustments
- Microdosing GLP-1 Drugs, How GLP-1 Drugs Affect the Brain & Improve Peripheral Artery Disease
- Vertex Islet Therapy Eliminates Severe Hypos & Reduces HbA1c
- Beta Bionics iLet Sales Surge
- SiBionics ‘World’s Thinnest’ CGM
- Vicentra BV’s Kaleido2 Patch Pump: Application for FDA Approval?
- Phenolic Preservatives and Glucose Sensors Create Inflammatory Responses
- States Trying to Curb AI Bot Prior Authorizations & Claims Reviews
Dexcom’s FDA warning letter reveals unauthorized changes to sensors by Elise Reuter for MedTechDive.com, 26 March 2025. Dexcom made a significant design change to a component used in its sensors and did not adequately validate the change, according to the warning letter.
A warning letter posted by the Food and Drug Administration revealed quality control issues with Dexcom’s continuous glucose monitors. The FDA raised concerns with a design change to a component used in the resistance layer of Dexcom’s sensors. According to the warning letter, the sensors with the new component were less accurate than those with the original component. Dexcom has ceased distribution of G7 sensors with the component, but the company’s response did not address affected G6 sensors. The letter concerns a chemical compound that the sensor wire is dipped in. Dexcom began producing the compound internally to add redundancy to its supply chain.
Read more: Dexcom’s FDA warning letter reveals unauthorized changes to sensors
Dexcom rejects claims of unauthorized device changes in FDA warning letter by Elise Reuter for MedTechDive.com, 27 March 2025. A company spokesperson said Dexcom plans to resolve the agency’s concerns but stated no design changes were made to its glucose sensors.
Dexcom pushed back on claims in a Food and Drug Administration warning letter that the company made unauthorized changes to its glucose sensors.
Company spokesperson Nadia Conard wrote in an email Tuesday that no design changes were made, contrasting with language sent in a warning letter to the company earlier this month. “Dexcom qualified a second source for one of its raw materials, developed since 2021, to ensure an uninterrupted supply to customers,” Conard wrote, adding that “extensive testing” showed the material met specifications.
Dexcom also rejected claims in the warning letter that the company made major changes to its devices without submitting a premarket notification. The company notified the FDA both informally and formally through 510(k) submissions, following the guidelines for non-significant changes.
Read more: Dexcom rejects claims of unauthorized device changes in FDA warning letter
MARD wars. More craziness in the world of CGM marketing from ATTD by Tim Street for Diabettech.com, 26 March 2025.
New CGMs on the European Market: As shown in the table below, there were a lot of challenger CGMs showing off their wares. And almost to a tee, they presented with MARD values that were as good as, or better than, those of the market leaders (ignoring that some present with a value to 2 or more decimal places, as if it makes them more accurate).
There’s been a lot of talk about standardization of the process by which CGM accuracy is measured to allow reliable comparisons across CGMs. It’s even now been discussed in symposia led by Abbott (who have themselves been called out for changing the process they used to create MARD between Libre2 and Libre3). But that still feels like a hope rather than a likelihood.
With this in mind, the table above presents a bit of a problem. Contextual details are not provided, usually because “The study is private and hasn’t been published yet”. We don’t know how they got it: Questions such as: How many people did they have in their study? How many sensors did they use? What was the population distribution? What were the numbers of datapoints in different glucose ranges? Were there any glucose manipulation challenges?
This is the crux of the issue. We have a number with no context. It is meaningless, but it’s okay to publish it, because apparently, study data was, or will be, included in the CE mark submission. A submission to a body that knows nothing about CGM.
If a company submits data for a CE mark, then that study data needs to be available for them to market with an MARD value. If they won’t or can’t, then any marketing must not include the MARD value. And if that study information isn’t available to the end user, the device shouldn’t be allowed onto a national tariff for easy access via the country’s healthcare provider. No “waiting to publish the data”. No “we’ll only supply it to clinicians”.
If you’re able to market and sell direct to consumers, you, as a manufacturer have an obligation to give us information to make the best and safest choices. Understanding how you arrived at a number (that you’ve published to 3 decimal places in some cases) is critical.
It’s that simple. Make all the data available to the end user or be forbidden from sharing the headline or accessing the healthcare system.
Tim Street asks: What do you think? I agree with him 1000%!
Read more: MARD wars. More craziness in the world of CGM
Looking for Glucose Patterns by Marissa Town for ChildrenWithDiabetes.com, 2 March 2025.
CGMs identify patterns for the wearer to aid in behavior modification. But how do you know what changes to make? Do you have to ask your endocrinologist to look at your data to make insulin adjustments? How will you know if the changes you made are working as intended?
Step 1: Looking at the Data: The Ambulatory Glucose Profile (AGP) is the current standard report for a continuous glucose monitor. This report includes information on Time in Range, glucose variability, and shows patterns that are seen in the CGM data. It also shows the average glucose over the period chosen, which can be up to three months, and provides a glucose management indicator (GMI). The GMI is an estimate of the HbA1c based on the CGM data, which is not meant to be a substitute for A1C measurements.
Step 2: Examining the Data: In general, the goals for Time in Range are >70%, for time low <4%, for very low <1%, for high <25%, and very high <5%.
Step 3: Interpreting the Data: 1. Look for Lows First; 2. Pattern = Consistent for at Least 3 Days; 3. Overnight Patterns are Usually Basal Related; 4. Post-Prandial (After meal) Highs
For more information on identifying patterns and adjusting insulin, check out these resources:
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- DiaTribe has a great article about using the AGP to identify patterns.
- CWD’s recorded session Making the Most of your Closed Loop System by Dr. Daniel DeSalvo
- Barbara Davis Center’s Panther Program has tips on how to make adjustments to different closed loop systems
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Read more: Looking for Glucose Patterns
Microdosing weight-loss drugs is on the rise – but does it work? by Sara Novak for NewScientist.com, 26 March 2025.
“Microdosing” – a practice more typically associated with psychedelics such as LSD and psilocybin – by taking lower-than-standard amounts of weight-loss drugs such as Wegovy and Mounjaro. For some, the hope is to avoid side effects while losing weight, while others want to tap into the anti-inflammatory effect of these medications or reap their other benefits for the heart and the brain. Microdosing the drugs has even been touted for extending longevity by ultra-wealthy elites, and is rumoured to be the secret weapon of Hollywood stars wanting to look svelte for photo calls.
The question is, does this off-label, low-dose experimentation work?
Al-Aly’s recent study in Nature identified a host of health benefits in addition to weight loss for those taking the medications, including a reduced risk of substance use disorders, Alzheimer’s disease, dementia, clotting disorders, and many other conditions. But these were at higher doses and there is no data to show that similar results will occur in those who microdose.
Whether the drugs are indeed a fountain of youth remains unclear, but we do know that they can dampen inflammation. “It is plausible that microdosing could provide some [anti]inflammatory benefits … but we just don’t know yet,” says Al-Aly.
Read more: Microdosing weight-loss drugs is on the rise – but does it work?
What do GLP-1 drugs really tell us about the brain’s reward system? by David Robson for NewScientist.com, 26 March 2025.
Many people are rhapsodising about the benefits of drugs like Wegovy and Ozempic – that these treatments are helping people curb their eating should be no surprise: that is exactly what they are meant to do, by mimicking the satiety hormone GLP-1. According to these accounts, when taking these drugs, the urge to drink alcohol, smoke, and even shop compulsively plummets (but not libido, though anecdotal reports on this subject elsewhere online are mixed). Such tales are becoming familiar to prescribing physicians.
Controlled clinical trials may tell us a lot about how the brain processes anticipation and reward, and could also suggest whole new ways of dealing with addiction. By targeting areas of the brain responsible for reward signals from food, GLP-1 drugs might also reduce the rewards people get from other things, such as addictive substances. But what does the current evidence show about these complex behavioral processes?
First, we need to understand how drugs like Ozempic interact with and influence the brain. In general, GLP-1 and the drugs that mimic it are too large to pass through the blood-brain barrier, but seem to be able to reach a few regions where the membrane is a little more porous. These include a region of the brainstem called the area postrema, which can generate feelings of nausea when activated by GLP-1 hormones, and the hypothalamus, which is involved in controlling our energy intake and expenditure.
Another pathway through which GLP-1 drugs may influence our behaviour is via the vagus nerve, which runs between the abdomen and the brain and helps regulate many bodily processes. We know that parts of the vagus nerve are sensitive to GLP-1, and changes to the activity of this nerve could have wide-reaching effects in brain areas like the mesolimbic system, which deals with reward processing.
Animal and human models suggest that the most significant effects of the new medications can be seen in mitigating the anticipation of food, rather than the pleasure derived from eating itself. “I’d say that’s fairly well established,” says Rodrigo Mansur at the University of Toronto. “And it’s something we hear often from patients – that they are just thinking less about the next meal.”
Read more: What do GLP-1 drugs really tell us about the brain’s reward system?
And more on semaglutide! STRIDE: Semaglutide Shows it Has Legs in Peripheral Artery Disease by Nicole Lou for MedPageToday.com, 29 March 2025.
Semaglutide further solidified its efficacy for diabetes-associated cardiovascular conditions, this time building its positions in peripheral artery disease (PAD) and with an oral formulation, based on two major studies.
In the randomized STRIDE trial, a year of semaglutide (Ozempic, Wegovy) injections increased the walking ability of people with type 2 diabetes (T2D) and lower limb PAD by 21%, a significant improvement over placebo’s 8% improvement. This makes semaglutide the first drug to show benefits in both cardiovascular outcomes and walking function, said Marc Bonaca, MD, MPH, of CPC Clinical Research and the University of Colorado School of Medicine in Aurora, at the American College of Cardiology (ACC) annual meeting.
Separately, in the SOUL trial of people with T2D who also had atherosclerotic cardiovascular disease and/or chronic kidney disease, several years of oral semaglutide (Rybelsus) reduced one’s risk of major adverse cardiovascular events (MACE) by the end of year 4, a positive result driven by the reduction of nonfatal myocardial infarctions in particular, according to Darren McGuire, MD, of UT Southwestern in Dallas.
Read more: STRIDE: Semaglutide Shows it Has Legs in Peripheral Artery Disease
Novel islet cell therapy eliminates severe hypoglycemia, cuts HbA1c in type 1 diabetes by Michael Monostra for Healio.com/endocrinology, 28 March 2025.
A novel islet cell therapy delivered through a single infusion lowered HbA1c and eliminated severe hypoglycemia events for all adults with type 1 diabetes who received a full dose, according to data from a phase 1/2 study.
The FDA cleared an investigational new drug application for VX-880 (Vertex Pharmaceuticals) to treat adults with type 1 diabetes who experience recurrent severe hypoglycemia. Vertex presented data from the first two participants who received a half dose of VX-880 at the American Diabetes Association Scientific Sessions in 2022.
At the International Conference on Advanced Technologies & Treatments for Diabetes, Michael R. Rickels, MD, MS, the Willard and Rhoda Ware Professor in Diabetes and Metabolic Diseases in the division of endocrinology, diabetes and metabolism, and medical director of the pancreatic islet cell transplant program at University of Pennsylvania Perelman School of Medicine, presented additional data from 14 adult participants in the phase 1/2 FORWARD trial.
“The full dose of VX-880, given as a single infusion, demonstrates consistent engraftment of islets with restoration of endogenous insulin secretion, elimination of severe hypoglycemia and significant improvement of glycemic control,” Rickels said.
Read more: Novel islet cell therapy eliminates severe hypoglycemia, cuts HbA1c in type 1 diabetes
Newly public Beta Bionics reports sales surge by Nick Paul Taylor for MedTechDive.com, 28 March 2025.
Beta Bionics reported its first quarterly results as a public company. Sales jumped 145% to $20.4 million in the fourth quarter, 2% above the consensus estimate of Wall Street analysts. The performance was driven by nearly 4,100 new patient starts, a figure that is at the high end of the range the insulin pump company forecast in its initial public offering paperwork. Beta Bionics signed two large formulary contracts in late 2024 and early 2025 and expects the pharmacy channel to account for more than 20% of new patients starting this year. Expansion into the pharmacy will provide [Beta Bionics] with clear tailwinds to both the top and bottom line in the intermediate to long term.
Read more: Newly public Beta Bionics reports sales surge
SiBionics unveils ‘world’s thinnest’ CGM, earns CE mark by Sean Whooley for MassDevice.com, 26 March 2025.
SiBionics announced today that it unveiled its GS3 continuous glucose monitor (CGM), which now has CE mark approval. The company unveiled the device, which it touts as the world’s thinnest CGM, at last week’s 18th International Conference on Advanced Technologies & Treatments for Diabetes (ATTD) in Amsterdam. GS3 features an ultra-compact design and three-second activation. With a thickness of just 2.9 mm, China-based SiBionics compares its size to that of a small coin. It also weighs just 1.5 grams, which the company says makes it “almost unnoticeable when worn.”
SiBionics brings the GS3 CGM to the market at an interesting time as it remains embroiled in a patent battle with leading CGM maker Abbott. Last summer, The Hague said the company can’t distribute its CGMs in Germany, France, the Netherlands, and Ireland.
Read more: SiBionics unveils ‘world’s thinnest’ CGM, earns CE mark
ViCentra recently appointed Tom Arnold as its new CEO to accelerate growth for the Kaleido automated insulin delivery system. Arnold joins the Dutch insulin pump maker with nearly 25 years of leadership experience in medtech and diabetes. Before taking the corner office at ViCentra, Arnold held leadership roles at Medtronic, Procept BioRobotics, Boston Scientific and Sorin Group. Most recently, he served as VP of global marketing at Procept. Before that, he was VP of commercial strategy and enablement at Medtronic.
Arnold also has a personal connection with diabetes management. His youngest daughter was diagnosed with type 1 diabetes at 11 months old and has worn an insulin pump for 17 years.
Read more: ViCentra picks former Medtronic leader as CEO to expand access to automated insulin delivery tech
Phenolic Preservatives Are Not the Sole Cause of Eosinophilic Infiltration at Infusion Pump Sites by Priscilla Silva Cunegundes, Kenneth Wood, Li Mao & Ulrike Menkes, published by Diabetes Technology & Therapeutics, 11 March 2025.
Skin reactions and discomfort associated with insulin infusion pumps limit user adherence. A recent histopathological study by Kalus et al. (DERMIS study) reported increased eosinophilic infiltration and imputed an inflammatory response to an allergen delivered at the catheter tip. This finding might explain the pruritus reported by pump users. As eosinophils migrate to inflammatory foci, primarily due to IL-5 and CCL11, we aimed to evaluate insulin phenolic preservative (IPP) as a potential allergen in vitro and assess tissue eosinophilic infiltration in vivo.
These findings suggest that IPP is not the only triggering allergen, as IPP did not induce eosinophils in vitro, while glucose sensors also indicated increased eosinophilic infiltration. Therefore, factors other than IPP trigger eosinophil recruitment to insulin infusion pump sets.
https://doi.org/10.1089/dia.2025.004
Read more: Phenolic Preservatives Are Not the Sole Cause of Eosinophilic Infiltration at Infusion Pump Sites
States try to rein in health insurers’ claim denials, with mixed results by Shalina Chatlani for Stateline.org, 25 March 2025.
Health insurance companies are under increasing scrutiny for allegedly using artificial intelligence bots and algorithms to swiftly deny patients routine or lifesaving care, without a human actually reviewing their claims.
As more patients and doctors voice their frustrations, states are responding with legislation designed to regulate prior authorization and claims reviews. So far this year, lawmakers in more than a dozen states are considering measures that would, for example, limit the use of AI in reviewing claims; exclude certain prescription medications from prior authorization rules; ensure that emergency mental health care is not delayed for more than 48 hours; and require that insurers’ review boards include licensed physicians, dentists or pharmacists with clinical experience.
Insurers have long required doctors to obtain their approval before they will pay for certain drugs, treatments, and procedures. They argue it is necessary to rein in health care costs and limit unnecessary services. But many doctors and patients say the practice has gotten out of hand, causing delays and denials of care that are harming and even killing people.
In a survey last year by the American Medical Association, 93% of doctors said that insurers’ prior authorization practices delayed “necessary care” for their patients. Twenty-nine percent said such delays had led to a “serious adverse event,” such as hospitalization, permanent injury, or death.
In 2023, insurers selling plans on the marketplaces created under the Affordable Care Act denied a combined average of 20% of all claims. Of the 73 million in-network claims they denied, only 1% were appealed, according to KFF, a health policy research group.
Read more: Health Care States try to rein in health insurers’ claim denials, with mixed results
Thank you for bringing attention to the MARD issue.