Hypoglycemia Flashcards
What is classified as hypoglycemia
Less than 50mg/dL = 2.8mmol
Which part of the developing brain is most likely to be affected by recurrent hypoglycemia?
occipital lobe
How does a foetus get glucose?
Placental transfer Catecholamine release (hypoxia) mobilises fetal glucose and FFA. (can also inhbit insulin and stimulate glucagon)
What happens to glucose homeostasis at delivery?
acute interruption of glucose transfer
Stress -> 3-5x increase in glucagon.
Insulin usally falls and remain low for days
Surge in catecholamine secretion (adrenaline)
GH elevated at birth
Glucose mobilised via GNG and glycogenolysis, activate lipolysis and promote ketogenesis.
Liver glycogen depleted within hours of birth. GNG from alanine account for 10% of glucose turnover. FFA also increase.
What happens to the following in hyperinsulinemic states? Glucose Insulin Ketones Alanine Lactate Urinary ketones
Glucose very low. Insulin elevated (usually >2 in setting of hypo) Ketones low Alanine normal Lactate normal Urinary ketones 0 IGFBP1 - low
What happens to the following in ketotic hypoglycemia from substrate deficiency? Glucose Insulin Alanine Lactate Ketones
Urinary ketones
Glucose low Insulin low Ketones ++ Alanine low Lacate normal Ketonuria++
What happens to the following in Fatty acid oxidation disorder? Glucose Insulin Ketones Alanine Lactate Urinary ketones
Glucose Low low
No ketones
Serum lipids and uric acid abnormal
What happens to the following in Hypopituitarism? Glucose Insulin Ketones Alanine Lactate Urinary ketones
Glucose low Insulin low Ketones ++ Alanine low Lactate normal Ketonuria ++
What medication can you use if someone has defect in SUR1/KIR 6.2 causing hypoglycemia?
Diazoxide - opens K-ATP channel so stops Ca inward flux - decreases insulin release.
Others - somatostatin also effective in 50% of cases.
(or octreotide)
If unaffective - pancreatectomy. (may need
What hormone is the cause of hypo unawareness?
adrenaline.
