Gluconeogenesis

A 34-year-old man with poorly controlled type 2 diabetes mellitus presents to the emergency department with severe hypoglycemia (blood glucose 38 mg/dL) during a 48-hour fast as part of a religious observance. He is conscious but confused. Serum insulin is suppressed (2 mIU/L), and C-peptide is undetectable. What is the most appropriate immediate next step in management?

A 48-year-old man with type 2 diabetes mellitus (HbA1c 9.2%) and chronic kidney disease stage 3b (eGFR 38 mL/min/1.73m²) is admitted with a 2-week history of poor oral intake due to uremia. His fasting blood glucose is 68 mg/dL (normal fasting 70–100 mg/dL), and he is asymptomatic. Serum electrolytes show potassium 6.8 mEq/L, phosphate 5.2 mg/dL, and bicarbonate 18 mEq/L. Urine output is 800 mL/24h. Which of the following best explains the paradoxically low fasting glucose despite diabetes?

A 3-year-old child presents with severe hypoglycemia (blood glucose 28 mg/dL) and hepatomegaly during a 6-hour fast. The child is lethargic and has seizure-like activity. Serum lactate is elevated at 8 mmol/L (normal <2). The parents report recurrent episodes after fasting or illness. Which investigation would best confirm a defect in gluconeogenesis?

A 38-year-old woman with type 2 diabetes is admitted with severe hypoglycemia (blood glucose 42 mg/dL) after 72 hours of fasting. Which finding best distinguishes impaired renal gluconeogenesis from impaired hepatic gluconeogenesis in her case?

A 28-year-old man with a known history of fasting-induced seizures since childhood is admitted with recurrent hypoglycemia (blood glucose 35–50 mg/dL) despite a 6-hour fast. His parents report that he requires frequent meals and cannot tolerate prolonged fasting. Liver ultrasound shows hepatomegaly with a smooth, non-cirrhotic appearance. Serum lactate is 8 mmol/L (normal < 2), and uric acid is markedly elevated at 9.2 mg/dL. Which of the following metabolic derangements is the PRIMARY consequence of the underlying enzyme defect?