RESUMEN
Euglycemic diabetic ketoacidosis (euDKA) is a rare but severe metabolic complication of diabetes mellitus characterised by elevated anion gap metabolic acidosis despite normal or mildly elevated blood glucose levels. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have emerged as effective antidiabetic medications, yet their use is associated with an increased risk of euDKA, especially when coupled with insulin dose reduction. We present the case of a 50-year-old male with a 20-year history of diabetes mellitus, initially managed with insulin and metformin, who developed euDKA following the introduction of empagliflozin and sitagliptin alongside a reduction in insulin therapy. Despite normoglycaemia the patient exhibited symptoms of ketoacidosis, including chronic fatigue, polydipsia, and polyuria. Diagnostic workup revealed metabolic acidosis, elevated inflammatory markers, acute kidney injury and ketonuria. Subsequent specialised laboratory tests confirmed type 1 diabetes mellitus (T1DM) with the presence of anti-glutamic acid decarboxylase (anti-GAD) antibodies and the absence of C-peptide secretion. Management involved fluid therapy, intravenous insulin and glucose administration. This case underscores the diagnostic challenges of euDKA and emphasises the importance of differentiating between T1DM and T2DM, as management strategies vary significantly. Patient education on insulin therapy and injection techniques is crucial to prevent complications such as improper insulin delivery and dose reduction, which can precipitate euDKA. In conclusion, clinicians should be vigilant for euDKA in patients on SGLT2 inhibitors, particularly when insulin dose reduction is involved. Comprehensive patient education and accurate differentiation between diabetes types are essential for timely diagnosis and optimal management, thereby reducing the risk of severe complications. LEARNING POINTS: The reduction in insulin doses combined with the introduction of an SGLT2 inhibitor in a patient with type 1 diabetes may lead to the development of a dangerous health complication known as euglycemic diabetic ketoacidosis.In cases of diagnostic uncertainty regarding the differentiation of diabetes types, measuring the levels of C-peptide and anti-GAD antibodies can be helpful.Abnormal glycaemic results in a patient using insulin may result from improper administration. During follow-up visits, it is worthwhile to check the subcutaneous tissue for lipodystrophy and also remind the patient about the necessity of rotating insulin injection sites.