Hypoglycemia

Question 1

Hypoglycemia Sxs

Answer 1

• At 80mg/dl insulin release declines, at 65-70 glucagon and epinephrine release is triggered, and <50): confusion, lethargy, stupor, combativeness
• And lower than 30: loss of conscience, seizure, death

Question 2

Whipples triad

Answer 2

• A description of hypoglycemia: low blood sugar, w/ Sx of hypoglycemia that is reversed w/ returning the glc to normal levels
• Most of the Sx are first caused by autonomic (sympathoadrenal) activation, then by neuroglycopenia

Question 3

Pathogenesis of hypoglycemia

Answer 3

• Hypoglycemia happens when there is: inadequate substrate for GNG and FA production
• Liver function is not adequate to perform GNG and FA oxidation
• Hormone deficiencies preventing the induction of key GNG nzs
• Inappropriate levels of insulin/IGF which prevents hepatic glc production and/or stimulate excessive glc utilization by muscle

Question 4

Pts at risk for hypoglycemia

Answer 4

• Mostly pts being treated for diabetes (both T1 and T2), also those who are pre diabetic and have insulin resistance
• T2 diabetics can still make glucagon (T1 can’t) and thus are much less likely to get hypoglycemic than T1
• Usually due to high insulin levels (most often exogenous)
• Rare causes: insulinomas

Question 5

Causes of hypoglycemia

Answer 5

• Healthy appearing: drugs (etoh, salicylates, quinine, haloperidol), insulinoma, islet cell hyperplasia/nesidioblastosis (islet cell hyperplasia in infants), insulin abuse, intense activity
• Ill appearing: shock, insulin (IV, SQ), pentamindine, bactrim, childhood diseases, hypopituitarism, hypoadrenalism, ACTH deficiency, tumors, starvation/anorexia

Question 6

Counter-regulatory mechanisms for hypoglycemia

Answer 6

• In order of first to last after hypoglycemia begins
• Glucagon release (60 mg/dl glc): stimulates glycogenolysis, lipolysis, GNG, suppresses insulin release
• Adrenaline (60): decreases peripheral utilization of glc and stimulates GNG and lipolysis in liver
• Cortisol/GH (40): decreases peripheral utilization of glc and enhances glc production by the liver
• These responses are triggered by: receptors in CNS to glc levels, hypoglycemia itself stimulates glucagon, glc sensors in liver

Question 7

Impaired counter-regulatory responses in diabetes 1

Answer 7

• T1: T1 diabetics have reduced glucagon response soon after developing DM (probably from heavily relying on exogenous insulin), thus the pts rely on autonomic responses to maintain high enough glc levels
• Eventually the autonomic response is also blunted and they develop hypoglycemia unawareness where they no longer experience the warning Sx of early hypoglycemia

Question 8

Impaired counter-regulatory responses in diabetes 2

Answer 8

• T2: more likely to complain of feeling unwell at normal glc levels (altered glycemic threshold)
• This is b/c if blood glc levels have been running high for a long time a new homeostasis is established and the pt acclimates to the high glc level
• These pts will report feeling unwell when glc is around the low 100s, and they will have an exaggerated adrenaline response when glc gets to 80-90
• This is thought to be due to down-regulation of glc receptors in the brain and can be reversed if they control their glc and do not treat the Sx unless the glc falls below 80

Question 9

Rx of hypoglycemia

Answer 9

• 10-15g of glucose should be given, the best is 4oz of a regular caffeinated soda (1/2 a normal can)
• After 10 min the glc levels should be checked, if there is no improvement then repeat glc administration
• If there are 3 glc administrations and no improvement they need to be hospitalized (for IV glc)
• Avoid using complex cards since they are less easily digested and utilized, sugary drinks are best
• Glucagon injections can work if the person does it correctly