hypoglycemia Flashcards
When does hypoglycemia occur
Hepatic Gluconeogenesis/Glycogenolysis falls below rate of Glucose uptake in Peripheral Tissues; Inhibition can occur due to Insulin, Depletion can occur in Malnutrition/Fasting, Exercise or Advanced Liver Disease, or Gluconeogenesis can be impaired, for example, post Alcohol ingestion
What increase glucose uptake
Insulin or Exercise; Balanced by Hepatic output
* Presents as Diplopia, Sweating, Palpitations, Weakness, Confusion/Abnormal Behaviour, Loss
of Consciousness and Generalised Seizures; Brain uses 50% of Hepatic Glucose output
How to manage hypoglycaemia
Oral Sugar and Long Acting Starch; If episodes often, advice many small high-starch meals
* Hypoglycaemia Coma – IV 20-30g Glucose; Glucagon 1mg IV/IM possible, but not if drunk
Why may hypoglycaemia develop in presence of alcohol
Primes cells to produce exaggerated response to cells in response to Carbohydrate
Inhibition of Gluconeogenesis; Occurs in Chronic Alcoholics, Binge
Drinkers and Children (Diminished Hepatic Reserve)
How can gastric surgery lead to hypoglycaemia
Can also occur post Gastric Surgery; Rapid Gastric Emptying results in mismatch between Nutrient absorption and Insulin secretion (Dumping)
What are endocrine causes of hypoglycaemia
Deficiency of Insulin Antagonistic Hormones e.g. Hypopituitarism, ACTH
deficiency, Addison’s Disease
What drugs can lead to hypoglycaemia
Sulfonylureas, Quinine,
Salicylates, Propranolol, Pentamidine
What are pancreatic islet cell tumours (insulinoma) associated with
Associated with Multiple Endocrine Neoplasia, presents with Fasting Hypoglycaemia
What is whipples triad
Whipple’s triad is a collection of three signs (called Whipple’s criteria) that suggests that a patient’s symptoms result from hypoglycaemia that may indicate insulinoma.
How to diagnose an insulinoma
Measurement of Overnight Fasting Glucose and Insulin on three occasions; Low Glucose and Normal/Elevated Insulin in 90% of Insulinoma patients; 72 hour fast if inconclusive
How to localise insulinoma
Selective Angiography, Contrast HRCT, Radiolabelled Somatostatin Scanning (Some tumours express Somatostatin Receptors), Endoscopy; Venous sampling for High Insulin concentration
How to treat insulinoma
Surgery excision
What medical therapy is used in insulinoma
Diazoxide useful if Malignant Insulinoma; May also remit with Somatostatin Analogue (Octreotide, Lanreotide)
