12.7 Hypoglycemia

Question 1

Take home messages

Answer 1

• Hypoglycemia - excessive lowering of blood glucose
• unexplained reduced conciseness = check for hypoglycaemia
• DM - insulin deficiency (-> Hyperglycemia)
• treatment: reduces blood glucose

Question 2

What is the normal blood glucose range?

Answer 2

3.9-5.5 mmol/L

Question 3

Define hypoglycemia

Answer 3

• abnormal reduction or lowering of blood glucose
• common in patients with diabetes mellitus on treatment that aims to reduce elevated blood glucose levels
• spontaneous hypoglycemia in otherwise normal and healthy individuals rare, but important to recognise

Question 4

Neuroglycopenia

Answer 4

Brain not supplied with enough glucose

adrenergic response
- noradrenaline / acetylcholine
- mobilize glycogen and fat as additional fuel
- Liver: Glucose ➡️Brain
- Fat stores: FFA ➡️other

hormonal response
- Insulin ⬇️
-Insulin antagonists ⬆️
➡️Cathecholamines (adrenaline): alarm
➡️Glucagon: immediate, most important, silent
➡️Cortisol (slower response)
➡️GH (slower response)

Question 5

What is the most important protector against hypoglycemia?

Answer 5

Glucagon (acts immediately)
- released when glucose and insulin in low

Question 6

Role of catecholamines (adrenaline)

Answer 6

• mainly responsible for hypoglycemic symptoms
• ALARM
• acts immediately, major back-up system for glucagon

Question 7

What does cortisol and growth hormone do with glucose balance

Answer 7

• Cortisol: mobilize energy stores (2-3 hrs)
• Growth hormone: antagonize insulin-effects (after hours)
• these hormones work synergistically - combined hyperglycemic effect more than individual impact
• Hypoglycemia: ⬆️ cortisol; ⬆️ GH

Question 8

Symptoms of hypoglycemia are due to:

Answer 8

• counter regulatory mechanisms NB: adrenergic response
• Adrenergic symptoms: BG < 3.8mmol/l
• inadequate glucose delivery to the brain with resultant dysfunction due to neuroglycopenia
• Neuroglycopenic symptoms: BG < 2.8mmol/l

Question 9

Adrenergic symptoms

Answer 9

• Anxiety
• Tremor
• Sweating
• Hunger
• Palpitations
• more prominent
• evokes similar symptoms repeatedly in same patient
• ALARM: main warning of falling blood glucose level

Question 10

Neuroglycopenia

Answer 10

• Vision
• Weakness
• Tiredness
• Confusion
• Behavioral abnormalities
• Dizzy…..
• Convulsions
• Coma
• patient presents with subtle to overt features of brain dysfunction

Question 11

Diagnosis of Hypoglycemia

Answer 11

• suspect clinically: symptoms and signs non-specific and raise suspicion only
• confirm biochemically: ideally laboratory confirmation of low blood glucose
• Whipple triade must be present especially in patients without known diabetes
• remember normal physiology and expected low insulin if hypoglycemia

Question 12

Nb Whipples traide (diagnostic triade for hypoglycemia)

Answer 12

Traide
- symptoms and signs of hypoglycemia
- laboratory confirmed plasma glucose <2.5 (2.7) mmol/l [<45 (50)mg/dl]
- reversal of symptoms with glucose administration

• blood glucose values applicable to non-diabetic population
• must confirm clinical suspicion biochemically
• symptoms non-specific
• in patients with diabetes on glucose lowering treatment, we use a higher cut-off for diagnosing hypoglycemia, namely 4.0mmol/L (72mg/dl) as these patients are at high risk for low sugars

Question 13

Classification of hypoglycemia

Answer 13

(1) in background population without diabetes mellitus
- a blood glucose below 2.7 (2.5 mol/L) along with other Whipple triad criteria

(2) in patients with diabetes mellitus on treatment
- classification based on clinical presentation and blood glucose measurement
- includes all episodes of an abnormally low plasma glucose concentration (with or without symptoms) that expose the individual to harm:
• Level 1: blood glucose less than 3.9 mmol/L (54mg/dl) but _>3mmol/L (70mg/dI)
• Level 2: blood glucose < 3mmol/L
• Level 3: any episode of hypoglycemia where third-party assistance or other resuscitative measures required ( do not wait for sugar test result, treat immediately)

Question 14

Etiology / pathophysiology

Answer 14

fasting hypoglycemia
- in an otherwise healthy person should always be thoroughly investigated. May indicate the presence of a serious, and potentially curable, underlying condition.

postprandial hypoglycemia
- is self-limiting, do not produce ominous symptoms, is non-progressive and rarely suggestive of underlying disease. Is mostly seen in association with previous gastric surgery / psycho- pathology

Question 15

Fasting hypoglycemia presents

Answer 15

• at night-time
• early morning on waking
• provoked by exercise
• during fasting period in the day-time

Question 16

What factors predispose pt with diabetes to hypoglycemia

Answer 16

Slide 33

Question 17

Fasting hypoglycemia in pt without diabetes

Answer 17

• rare but important
• inappropriate high insulin levels (patient otherwise healthy): a. endogenous excess production = INSULINOMA
• normal/reduced Insulin levels (patient usually sick with known primary ailment):
  a. malnourished alcoholic
  b. unwell patient {liver/kidney/ multiple organ failure: certain endocrinopathies (cortisoldeficiency)}

Question 18

Fasting hypoglycemia in the patient without diabetes and with high insulin levels = Insulinoma

Answer 18

• rare insulin secreting tumors of the pancreatic β-cells
• hallmark the inappropriate uncontrolled release of insulin irrespective of blood glucose
• hypoglycemia with high insulin levels in patient not on treatment for diabetes

when should I suspect this condition in my patient??
- hypoglycemic symptoms in the fasting state or worsened by exercise in someone who is not on treatment for diabetes with symptoms like what you have seen in your patients with diabetes and who otherwise appears well
- Whipple triade present
- weight gain due to defensive eating in presence of recurrent hypos
- recurrent unexplained neurological episodes especially in fasting state (they lose their adrenergic awareness and present with neuroglycopenia)

Question 19

Hypoglycemia with low insulin levels (alcohol)

Answer 19

NB: alcohol abuse an important cause of hypoglycemia and a reason for a suppressed consciousness to consider in emergency units especially if associated hypothermia

Question 20

Summarize

Answer 20

• always consider hypoglycemia in emergency units in patients with suppressed level of consciousness, no harm done in giving unnecessary IV dextrose if uncertain
• think of hypoglycemia if your patient present with the symptom complex that you have observed in your treated diabetes patients or if your patient presents with unexplained repeated neurological symptoms especially in fasting state (nighttime)