Empagliflozin-associated euglycemic DKA

 

Empagliflozin and Euglycemic Diabetic Ketoacidosis (EDKA): Mechanism, Risk Factors, and Clinical Implications

Introduction

Empagliflozin is a sodium–glucose cotransporter-2 (SGLT2) inhibitor widely used in type 2 diabetes mellitus, heart failure, and chronic kidney disease because of its proven cardiovascular and renal benefits. Despite these advantages, SGLT2 inhibitors are associated with a rare but serious complication: euglycemic diabetic ketoacidosis (EDKA). Unlike classic diabetic ketoacidosis (DKA), EDKA occurs with normal or mildly elevated blood glucose levels, making diagnosis challenging and often delayed.

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What Is Euglycemic DKA?

Euglycemic DKA is defined by:

Metabolic acidosis (pH < 7.3, bicarbonate < 18 mmol/L)

Elevated serum or urine ketones

Blood glucose typically < 250 mg/dL

Because hyperglycemia is absent, clinicians may overlook DKA unless ketones and acid–base status are specifically assessed.

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Mechanism: How Empagliflozin Causes EDKA

1. Increased Urinary Glucose Loss (Glycosuria)

Empagliflozin inhibits SGLT2 in the proximal renal tubules, reducing glucose reabsorption and increasing glucose excretion in urine. This lowers plasma glucose independently of insulin.

2. Reduction in Plasma Glucose Levels

Lower blood glucose leads to decreased pancreatic insulin secretion. Insulin deficiency, even if relative, is a key trigger for ketogenesis.

3. Decreased Insulin Levels

Low insulin reduces glucose utilization by peripheral tissues and removes inhibition on lipolysis.

4. Increased Glucagon Secretion

SGLT2 inhibitors increase the glucagon-to-insulin ratio. Elevated glucagon promotes:

Lipolysis

Hepatic free fatty acid delivery

Ketone body production

5. Enhanced Lipolysis and Ketogenesis

Free fatty acids are converted in the liver to ketone bodies (β-hydroxybutyrate and acetoacetate), leading to rising ketone levels despite near-normal glucose.

6. Ketone Accumulation and Metabolic Acidosis

Excess ketones overwhelm buffering systems, resulting in high anion gap metabolic acidosis — the hallmark of EDKA.

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Why Blood Glucose Remains Normal

Continuous urinary glucose loss prevents marked hyperglycemia

Reduced hepatic glucose output due to lower insulin requirements

Ongoing caloric deficit and dehydration further limit glucose rise

This “masked” presentation explains why EDKA is frequently underdiagnosed.

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Risk Factors for Empagliflozin-Associated EDKA

Type 1 diabetes (off-label use)

Low carbohydrate or ketogenic diets

Prolonged fasting or starvation

Acute illness, infection, or surgery

Excess alcohol intake

Insulin dose reduction or omission

Dehydration

Pregnancy

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Clinical Presentation

Symptoms are often nonspecific and may include:

Nausea and vomiting

Abdominal pain

Fatigue

Dyspnea (Kussmaul breathing)

Altered mental status

Blood glucose may appear reassuring, delaying recognition.

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Diagnosis

Key investigations include:

Arterial or venous blood gas (metabolic acidosis)

Serum β-hydroxybutyrate

Urine ketones

Anion gap calculation

Blood glucose (often normal)

A high index of suspicion is essential in any unwell patient on SGLT2 inhibitors.

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Management

Immediate discontinuation of empagliflozin

Intravenous fluids (initially isotonic saline)

Insulin infusion (even with normal glucose)

Dextrose infusion to prevent hypoglycemia while continuing insulin

Electrolyte monitoring and replacement

Management principles are similar to classic DKA, with added attention to glucose supplementation.

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Prevention Strategies

Avoid SGLT2 inhibitors in type 1 diabetes unless clearly indicated and supervised

Hold empagliflozin during acute illness, surgery, or prolonged fasting (“sick day rules”)

Educate patients about warning symptoms

Avoid very low-carbohydrate diets while on therapy

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Conclusion

Empagliflozin-associated euglycemic DKA is an uncommon but potentially life-threatening complication. Its atypical presentation with normal glucose levels requires heightened clinical awareness. Understanding the underlying pathophysiology—reduced insulin, increased glucagon, and enhanced ketogenesis—is crucial for early diagnosis, prompt treatment, and prevention.