Endocrine Abstracts

JOINT3936

Background: ¹Metformin use in patients with type 2 diabetes (T2D) is associated with lactic acidosis, although exceedingly rare. ²However, the risk of lactic acidosis is high in patients with underlying CKD. SGLT2 inhibitors have been increasingly used in patients with CKD in recent years due to their benefit in preventing the progression of diabetic nephropathy. In this case, we present the case of a 79-year-old elderly patient with T2D using both Metformin and an SGLT2 inhibitor who was admitted for life-threatening lactic acidosis.

Clinical Case: A 79-year-old female with T2D and co-morbidities including CKD 3b, HTN HLD, and dementia, presented with altered mental status. Her home medications included Dapagliflozin 5 mg (started 6 months ago), Metformin XR 500 mg BID (started 8 years ago), Amlodipine, Atenolol, Hydrochlorothiazide, Olmesartan, and Rosuvastatin. Upon admission, she exhibited severe hypotension (BP: 74/35 mmHg), bradycardia (HR: 54 bpm), and hypothermia (Temp: 34.4°C), while maintaining normal oxygen saturation. Laboratory results showed glucose at 94 mg/dL, potassium at 6.8 mEq/l, BUN at 45 mg/dL, creatinine at 8.86 mg/dL (baseline: 1.3 mg/dL), anion gap at 37.4, pH at 6.8, HCO3 at 2.6 mmol/l, PCO2 at 15 mmHg, lactate at 19.9 mmol/l (reference range < 2), and urine positive for ketones. Despite intensive care with intravenous hydration, a bicarbonate drip, and three vasopressors, her hypotension persisted, and lactate levels rose to 24 mmol/l. Emergent continuous renal replacement therapy (CRRT) was initiated, which improved her hemodynamics and lactic acidosis—all potential causes of lactic acidosis, including infection work-up such as blood cultures, were negative.

Conclusion: Although it is often challenging to identify the exact cause of lactic acidosis, her clinical picture raised suspicion of metformin-induced lactic acidosis due to the initial failure to respond to fluid resuscitation and pressors, followed by improvement after CRRT, and a negative work-up for infection and other causes. ³There is a similar case presenting severe euglycemic ketoacidosis and lactic acidosis in a diabetic patient on chronic Dapagliflozin and Metformin therapy, which was triggered by poor oral intake and dehydration, ultimately requiring dialysis. Our case underscores the caution needed when using a combination of metformin and SGLT-2 inhibitors, especially in elderly T2D patients with decreased GFR.