MON-608 - When Sugar Floods the System: Hyperosmolar Hyperglycemic State as the First Manifestation of Diabetes in A Young Adult

Background

Hyperosmolar hyperglycemic state (HHS) is a life-threatening metabolic emergency typically seen in older adults with long-standing type 2 diabetes mellitus. Presentation as the initial manifestation of diabetes in younger individuals is uncommon and may delay diagnosis, allowing severe metabolic derangements to develop.

Case Presentation

A 37-year-old previously healthy man presented with one week of progressive generalized weakness and profound dehydration following an acute gastrointestinal illness. To compensate for poor oral intake, he consumed large volumes of sugar-containing beverages. He denied any prior history of diabetes and had no routine medical care. On examination, he appeared markedly volume depleted with severe xerostomia and persistent polydipsia.
Initial laboratory evaluation revealed extreme hyperglycemia with a serum glucose of 1,651 mg/dL. Venous blood gas showed pH 7.24, bicarbonate 24 mmol/L, and a mildly elevated anion gap of 18.6 mmol/L. Urinalysis demonstrated significant glucosuria without ketonuria, supporting HHS rather than diabetic ketoacidosis. Effective serum osmolality was critically elevated 400 mOsm/kg. Additional findings included hemoconcentration (hemoglobin 18.9 g/dL), acute kidney injury with creatinine 3.2 mg/dL, and corrected hypernatremia peaking at 161 mmol/L. Mild lactic acidosis and troponin elevation were attributed to hypoperfusion and demand ischemia. Infectious workup was unrevealing.
The patient was admitted to the intensive care unit and treated with aggressive isotonic fluid resuscitation, continuous intravenous insulin infusion, and close metabolic monitoring. His course was complicated by refractory hypernatremia and severe hypophosphatemia, requiring nephrology consultation and targeted electrolyte replacement. Gradual correction of hyperosmolarity led to improvement in mental status, renal function, and metabolic abnormalities. He was transitioned to basal–bolus subcutaneous insulin therapy and received comprehensive diabetes education prior to discharge.

Discussion

Although 20–30% of HHS cases represent the first presentation of diabetes, occurrence in younger adults remains rare. Residual endogenous insulin likely suppressed ketogenesis, permitting progressive hyperglycemia and hyperosmolarity. Acute gastrointestinal illness combined with excessive intake of sugar-sweetened beverages served as key precipitants, highlighting the diagnostic challenge of HHS in nontraditional populations.

Conclusion

This case demonstrates a rare and severe presentation of HHS as the initial manifestation of type 2 diabetes in a young adult. It emphasizes the importance of early recognition of HHS outside classic risk groups and careful correction of volume and electrolyte abnormalities to prevent life-threatening complications.

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