Hypoglycemia

Thanks Joel for presenting a great case! And thanks to James Lundblad for coming and sharing his wisdom. This was a case of a patient who presented with hypoglycemia found to have a new diagnosis of widespread diffuse large B-cell lymphoma.

(Img: [https://i.ytimg.com/vi/YA91m_--WAg/hqdefault.jpg][0])

(Img: [https://i.ytimg.com/vi/YA91m_--WAg/hqdefault.jpg][0])

Main points:

  • 1) In approaching hypoglycemia, document Whipple’s triad of (1) symptoms of hypoglycemia (2) low glucose at time of symptoms (3) resolution of symptoms after correction of hypoglycemia

  • 2) Symptoms of hypoglycemia can be classified as (1) secondary to adrenergic stimulation (tremors, anxiety, sweating) and (2) neuroglycopenia (confusion, fatigue, loss of consciousness, blurry vision, seizures, coma, etc.)

  • 3) Tumor-induced hypoglycemia can be secondary to several etiologies including high glucose consumption from rapidly dividing tumors OR paraneoplastic production of insulin or related hormones (IGF-1, somatostatin, etc)


Want to learn more?

Framework for hypoglycemia

Hypoglycemia can be broken down into those caused by increased insulin and those caused by decreased glucose.

Increased insulin

  • 1) Exogenous – think accidental vs surreptitious ingestion of insulin or sulfonylureas
  • 2) Endogenous – think insulinoma (more likely to have neuroglycopenic symptoms), anti-insulin antibodies, islet cell hypertrophy

Decreased circulating glucose

  • 1) Malabsorption – usually in patient s/p gastric bypass (usually see postprandial hypoglycemia)
  • 2) High glucose consumption – rapidly dividing tumors
  • 3) Poor gluconeogenesis/ low glycogen stores – malnutrition (eg alcohol use d/o), critical illness (sepsis, liver failure, renal failure, heart failure, adrenal insufficiency), ingestion of ackee fruit (per Peter Sullivan)
  • 4) Low glucagon - pancreatic failure of any cause

Tests to distinguish these causes (c-peptide, insulin, proinsulin, serum ketones) should be measured at the time of documented hypoglycemia or in consultation with endocrinology during a 72-hour fast.

Lactic acidosis

This is a great review article and table (below) of causes of lactic acidosis. While we usually think of and need to rule out decreased oxygen delivery/ tissue perfusion, there is a list of other conditions to think about such as diabetes, cancer 2/2 warburg effect, decreased clearance from liver disease, metformin, medications/ ingestions, and thiamine deficiency.