Continuous Ketone Monitoring Has Potential to Cut DKA in Diabetes
The development of an on-body continuous ketone monitor (CKM) is seen as potentially helpful for the prevention of diabetic ketoacidosis (DKA) and other clinical situations.
Speakers at two meetings held this month have addressed the potential usefulness of the technology for people with type 1 or type 2 diabetes as well as others, such as those who follow ketogenic diets.
In April 2021, the first-ever human study of Abbott Diabetes Care’s CKM device showed that the technology is feasible. In June 2021, JDRF issued a request for applications for funding the development of CKM technology specifically aimed at preventing DKA in people with type 1 diabetes.
And in early October, a 20-member panel published a consensus report on the science and potential uses of CKM technology.
Abbott CKM Device Measures the Most Prevalent Ketone Body in DKA
Ketone bodies are produced as an alternative energy source when body tissues are deprived of carbohydrates either due to lack of insulin (as in untreated type 1 diabetes), fasting/starvation, intensive exercise, or low-carbohydrate/ketogenic diets.
In people with type 1 diabetes, ketones can build up in the blood faster than they can be metabolized and the body becomes acidic, leading to DKA. In recent years, this phenomenon has also been reported in people with type 2 diabetes who take sodium-glucose cotransporter 2 (SGLT2) inhibitors, sometimes in the setting of normal blood glucose levels.
The presence of lower and less-dangerous levels of ketones, called ketosis, occurs with low-carbohydrate diets.
Current methods for measuring ketone bodies include urine test strips, breath ketone monitors, and blood monitors. All measure at single timepoints, and only the blood monitors measure the predominant ketone body present in DKA, beta-hydroxybutyrate (BHB). Urine strips measure acetoacetate and the breath meters measure acetone, both of which can underestimate total body ketone concentrations.
The investigational Abbott CKM, in contrast, measures BHB in subcutaneous tissue via a sensor and applicator that look identical to the company’s Freestyle Libre continuous glucose monitoring device.
In the feasibility study of the ketone monitor, which involved 12 people on low carbohydrate diets of whom just one had diabetes, the CKM sensor performed well against capillary ketone measurement over 14 days with a single calibration.
At the virtual Diabetes Technology Society (DTS) meeting earlier this month, study co-author Kristin Castorino, DO, said: “Capillary-based measurements are episodic, and urine ketone measurements have significant limitations.”
“When I explain this to patients, I use the analogy of the times when we actually used urine dipsticks to measure glucose, and how that’s considered old news and no longer relevant. The same can occur with acetoacetate on those urine ketone strips…It may not reflect the current BHB burden that the person might be experiencing.”
CKM, on the other hand, “can identify changing ketone levels and possibly flag significant changes, offering a new tool for the prevention and management of DKA in people with diabetes,” said Castorino, senior research physician at Sansum Diabetes Research Institute, Santa Barbara, California.
Anne L. Peters, MD, professor of medicine at the University of Southern California (USC) Keck School of Medicine, Los Angeles, and director of the USC clinical diabetes programs, also discussed CKM on November 9 at a half-day meeting sponsored by the Endocrine Society.
On the Abbott CKM device, she said: “I personally really want this to come to market because I like using SGLT2 inhibitors in people with type 1 diabetes, particularly for their cardiac and renal benefits.”
However, Peters pointed out, “I don’t even know what day-to-day ketone levels look like in any of my patients, so I would have to learn a lot…but I think a device like this has great potential.”
Of course, Castorino noted, much more research will need to be done, including in people with type 1 and type 2 diabetes, and those taking SGLT2 inhibitors, because ketone concentrations generated just from people on ketogenic diets were limited (87% of values were below 1.5 mM). And accuracy will likely require a plasma ketone assay as reference.
DTS Consensus Report: Looking to the Future
The consensus report was sponsored by DTS and led by DTS director David Klonoff, MD. It quotes data from the US Centers for Disease Control and Prevention (CDC) that the incidence of DKA in US adults rose from 19.5 per 1000 person-years in 2000-2009 to 30.2 per 1000 person-years in 2009-2014, resulting in $5.1 billion in healthcare expenditures in 2014.
Increases in DKA have also been noted during the COVID-19 pandemic, including among children presenting with new-onset type 1 diabetes.
The panel advises that anyone at risk for DKA should be counseled about their status and given prevention and treatment advice, particularly for sick-day preparation, including insulin, fluid replacement, and ketone testing using preferred methods (ie, blood rather than urine or breath).
The document also discusses the potential for integration of CKMs into automated insulin delivery systems, also known as an artificial pancreas, potentially adding extra protection. This might be needed in the cases of failure of insulin delivery, sick days, stress, reduced carbohydrate intake, high-intensity exercise, SGLT2 inhibitor use, pregnancy, heavy alcohol intake, prolonged sedentary state, and social isolation.
Endpoints for future studies, the panel said, include accuracy in all four ketone ranges — highest (DKA), mid-range (impending DKA), lower-range (diet-induced ketosis), and lowest (healthy controls) — and whether the devices enable reduction in emergency department visits or hospitalizations, possible in-hospital benefits, and patient-reported outcomes.
“Continuous ketone monitoring systems will need to be accurate, safe, effective, affordable, and cyber secure to be widely adopted,” the panel concluded.
The consensus report was funded by Abbott. Klonoff has reported serving on advisory boards related to digital health for Sanofi and Novo Nordisk, receiving research funding from Novo Nordisk, and receiving share options from Glooko. Castorino has reported receiving research support from Abbott Diabetes Care, Dexcom, Medtronic, Insulet, Abbott Labs, and Drawbridge, and is a consultant and/or speaker for Lilly and Dexcom. Peters has reported participating in advisory boards for Abbott Diabetes Care, AstraZeneca, Lilly, Medscape, Novo Nordisk, Vertex, and Zealand, receiving research funding from Dexcom, Abbott Diabetes Care, and Insulet, and owning stock options for Omada Health and Teladoc.
Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape, with other work appearing in The Washington Post, NPR’s Shots blog, and Diabetes Forecast magazine. She is on Twitter: @MiriamETucker.
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