The first time the term Euglycemic DKA(eDKA) was mentioned was in 1973- in British Medical Journal in patients who were diabetic but didn't have the full blown hyperglyecmic part. Compared to classic DKA, eDKA presents with mild to moderate hyperglycemia typically <300mg/dl blood glucose levels.
Why is this more important now?
In 2013, many SGLT2 inhibitors got approved for DM management( the glucoretics). The FDA performed a FAERS search of adverse effects with these agents and 73 cases were identified of ketoacidosis linked to SGLT-2 inhibitors. All patients required hospitalization, and 60% had DMII. Blood glucose levels ranged from 90mg/dl - 1300mg/dl( median 211). Timing of onset was around 43 days or starting or dose change of the agent. Majority of the cases also had dehydration, infection or change in insulin doses. No mortality has been reported with this effect. All patients respond quickly with intravenous hydration and insulin once recognized. The FDA did acknowledge that some of the cases occurred in DMI, where it's an off label use. More detail here.
Is it a class effect?
Yes. The initial FDA reporting was done with canagliflozin(invokana). A more recent study found an incidence rate of 0.07% with this agent. In a large study with dapagliflozin( Farxiga), 0.1% of patients got eDKA. Empagliflozin(Jardiance) also has been found to cause eDKA.
What are the risk factors for development of eDKA with SGLT2 inhibitors?
decrease in insulin use
Low carbohydrate diet
Reduction in caloric intake
Mechanism of action
Ketosis results from restriction of carbohydrate usage with increased reliance on fat oxidation for energy production. The pathogenesis of hyperglyemic DKA is well established. Since SGLT2 are glucoretics as described before, they can lead to volume depletion- like a diuretic and perhaps leading to a "starvation" like ketoacidosis with normal glucose levels. SGLT2 induced glycosuria can happen over 24 hours and this artificial low plasma glucose do not stimulate insulin. In eDKA, insulin deficiency and insulin resistance are milder; therefore, glucose overproduction and under-utilization are quantitatively lesser than in DKA. More importantly, renal glucose clearance (i.e., the ratio of glycosuria to prevailing glycemia) is twice as large with eDKA than with DKA. Ketoacidosis follows with the same sequence of events in eDKA as in DKA. Insufficient insulin levels will then decrease glucose utilization and promote lipolysis and ketogenesis. In addition, these drugs can increase glucagon levels leading to increase ketone production.
In summary, eDKA is pathophysiologically similar to DKA except for the circumstance—SGLT2-induced glycosuria—that “artificially” lowers plasma glucose levels and predisposes to increased ketogenesis.
Prevention and treatment
Blood and urine monitoring of ketones is essential especially when patients get ill or are experiencing one of the risk factors. Adequate hydration and carbohydrate intake will help and holding the offending agent is indicated. No data exists on a safe time to restart the agent.
Here is a nice review on this topic