Case Report: Euglycemic diabetic ketoacidosis as the initial presentation of adult-onset autoimmune diabetes in a treatment-naïve man
6 affiliations
- 1Department of Internal Medicine, S. Nijalingappa Medical College
- 2Department of Internal Medicine, Jaipur National University Institute of Medical Sciences and Research Centre
- 3Department of Internal Medicine, Topiwala National Medical College
- 4Department of Internal Medicine, MP Shah Government Medical College
- 5Department of Internal Medicine, Lakhimpur Medical College
- 6Department of Internal Medicine, National Pirogov Memorial Medical University
Abstract
Background: Autoimmune diabetes can begin in adulthood and is often initially mistaken for type 2 diabetes. Its first presentation as euglycemic diabetic ketoacidosis (EDKA), that is, ketoacidosis with a plasma glucose below 200 mg/dL (11.1 mmol/L), is uncommon and easily overlooked, particularly in a patient without known diabetes or sodium-glucose cotransporter-2 (SGLT2) inhibitor exposure.
Case presentation: A 34-year-old previously healthy, lean man (body mass index 21.4 kg/m²) presented with a three-day history of fatigue, nausea, reduced appetite, increased thirst, and mild dyspnea, with oral intake falling to approximately 700 kcal on the day before admission. He had a high anion gap metabolic acidosis (pH 7.23, bicarbonate 13 mmol/L, anion gap 22 mmol/L) with marked ketonemia (β-hydroxybutyrate 5.2 mmol/L), but a random blood glucose of only 198 mg/dL (10.99 mmol/L). He had no known diabetes, took no medications, and did not drink alcohol. Diabetes was established during the admission by a hemoglobin A1c of 7.1%, and positivity for GAD65, IA-2, and ZnT8 antibodies with a low fasting C-peptide (0.42 ng/mL) indicated adult-onset autoimmune diabetes. Infectious, alcoholic, toxicologic, lactic, renal, and adrenal causes were excluded, and the brief reduction in intake was insufficient to explain the severity of the ketoacidosis. The episode resolved within 24 hours with intravenous fluids, insulin infusion with concurrent dextrose, and potassium replacement. He was discharged on basal–bolus insulin and remained free of ketoacidosis at three months, with a persistently low C-peptide.
Conclusion: Clinically significant ketoacidosis can precede the diagnosis of diabetes and occur with a glucose below the conventional threshold. An unexplained high anion gap acidosis should prompt ketone measurement regardless of the glucose level or a history of diabetes. Whether this patient has latent autoimmune diabetes in adults (LADA) or adult-onset type 1 diabetes will require longer follow-up to determine.
Related
- Sodium-glucose cotransporter-2 inhibitor-associated euglycemic diabetic ketoacidosis in an adolescent with type 2 diabetes.
- Euglycemic Diabetic Ketoacidosis Following Ertugliflozin Initiation Precipitated by Norovirus Gastroenteritis
- Favorable CGM metrics do not exclude SGLT2 inhibitor-associated euglycemic diabetic ketoacidosis: an educational case report with narrative review of literature
- Comment on Lan et al. Reducing Diabetic Ketoacidosis in Pediatric Type 1 Diabetes: The Impact of Screening Programs and Early Disease-Modifying Treatment. J. Clin. Med. 2026, 15, 5865
- Euglycemic SGLT2 Inhibitor-Associated Ketoacidosis in a Nondiabetic Patient: A Case Report.
BibTeX
@article{prasad2026case,
title = {{Case Report: Euglycemic diabetic ketoacidosis as the initial presentation of adult-onset autoimmune diabetes in a treatment-naïve man}},
author = {Sai Prasad and Anukriti Sharma and Anubhooti Sharma and Nishita Malu and Tanisha Jindal and Parth Shah and Angshuman Borpatra Gohain and Dileep Raja Kuraku},
journal = {Frontiers in Endocrinology},
year = {2026},
month = oct,
doi = {10.3389/fendo.2026.1996912},
url = {https://www.frontiersin.org/articles/10.3389/fendo.2026.1996912/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Case Report: Euglycemic diabetic ketoacidosis as the initial presentation of adult-onset autoimmune diabetes in a treatment-naïve man
AU - Sai Prasad
AU - Anukriti Sharma
AU - Anubhooti Sharma
AU - Nishita Malu
AU - Tanisha Jindal
AU - Parth Shah
AU - Angshuman Borpatra Gohain
AU - Dileep Raja Kuraku
PY - 2026
DA - 2026/10/30
JO - Frontiers in Endocrinology
DO - 10.3389/fendo.2026.1996912
UR - https://www.frontiersin.org/articles/10.3389/fendo.2026.1996912/full
AB - Background: Autoimmune diabetes can begin in adulthood and is often initially mistaken for type 2 diabetes. Its first presentation as euglycemic diabetic ketoacidosis (EDKA), that is, ketoacidosis with a plasma glucose below 200 mg/dL (11.1 mmol/L), is uncommon and easily overlooked, particularly in a patient without known diabetes or sodium-glucose cotransporter-2 (SGLT2) inhibitor exposure. Case presentation: A 34-year-old previously healthy, lean man (body mass index 21.4 kg/m²) presented with a three-day history of fatigue, nausea, reduced appetite, increased thirst, and mild dyspnea, with oral intake falling to approximately 700 kcal on the day before admission. He had a high anion gap metabolic acidosis (pH 7.23, bicarbonate 13 mmol/L, anion gap 22 mmol/L) with marked ketonemia (β-hydroxybutyrate 5.2 mmol/L), but a random blood glucose of only 198 mg/dL (10.99 mmol/L). He had no known diabetes, took no medications, and did not drink alcohol. Diabetes was established during the admission by a hemoglobin A1c of 7.1%, and positivity for GAD65, IA-2, and ZnT8 antibodies with a low fasting C-peptide (0.42 ng/mL) indicated adult-onset autoimmune diabetes. Infectious, alcoholic, toxicologic, lactic, renal, and adrenal causes were excluded, and the brief reduction in intake was insufficient to explain the severity of the ketoacidosis. The episode resolved within 24 hours with intravenous fluids, insulin infusion with concurrent dextrose, and potassium replacement. He was discharged on basal–bolus insulin and remained free of ketoacidosis at three months, with a persistently low C-peptide. Conclusion: Clinically significant ketoacidosis can precede the diagnosis of diabetes and occur with a glucose below the conventional threshold. An unexplained high anion gap acidosis should prompt ketone measurement regardless of the glucose level or a history of diabetes. Whether this patient has latent autoimmune diabetes in adults (LADA) or adult-onset type 1 diabetes will require longer follow-up to determine.
SN - 1664-2392
ER -