Monitoring of Diabetes

Question 1

Benefits of good glycaemic control?

Answer 1

Outcomes are improved and mortality is reduced, as HbA1c decreases

Microvascular disease decreases and, in T1DM, so does macrovascular disease

Question 2

Describe HbA1c

Answer 2

Glycated Hb; HbA1c is the largest component of the glycated Hbs and is formed by non-enzymatic glycation of Hb on exposure to glucose

This increases in a predictable way in response to prevailing glucose

Question 3

What is HbA1c used for?

Answer 3

Measure of average BG over a prolonged period of time (6-8 weeks):
• Normal is <42 mmol/mol (6%)
• Pre-diabetes is 42-47 mmol/mol (6 - 6.4%)
• Diabetes is ≥ 48 mmol/mol (6.5%)

Question 4

Factors that can affect HbA1c?

Answer 4

Can increase or decrease due to:
• Hb variants (have a faster rbc turnover)
• Haemolytic anaemic, acute/chronic blood loss, pregnancy

Question 5

Target HbA1c in diabetics?

Answer 5

Target is 53 mmol/mol; in younger people, treatment is more aggressive and 48 mmol/mol is the target

Question 6

Limitations of HbA1c?

Answer 6

Only provides an average value for glycaemic control; BG levels can vary enormously, which is harmful for cells, but the HbA1c only provides the average; thus, the glucose profile is important

Question 7

Benefits and problems with glucose monitoring?

Answer 7

Benefits - glucose control, symptoms (hypo/hyperglycaemic), lifestyle and exercise motivation and carbohydrate counting is allowed

Problems - painful, intrusive and may cause discrimination

Question 8

Target blood glucose levels in children with T1DM?

Answer 8

On waking and before meals:
• 4-7 mmol/L

After meals:
• 5-9 mmol/L

Question 9

Target blood glucose levels in adults with T1DM?

Answer 9

On waking:
• 5-7 mmol/L

Before meals at other time of the day:
• 4-7 mmol/L

90 minutes before meals:
• 5-9 mmol/L

Question 10

Target blood glucsoe levels in T2DM?

Answer 10

Before meals:
• 4-7 mmol/L

2 hours after meals:
• <8.5 mmol/L

Question 11

Target blood glucose levels in pregnant women with diabetes?

Answer 11

Fasting:
• <5.3 mmol/L

1 hour after meals:
• <7.8 mmol/L

2 hours after meals:
• <6.4 mmol/L

Question 12

Options for BG monitoring?

Answer 12

Urine or blood testing for ketones

Continuous glucose monitoring system (CGMS)

Question 13

How to reduce a improve patient glycaemic control to target?

Answer 13

Gradually reduce to targets, otherwise they will feel hypoglycaemic at normal/higher than normal BG, i.e: their body has adapted

Question 14

Pros and cons of continuous glucose monitoring (CGM)?

Answer 14

Provides a more detailed review of glucose control but has limitations:
• Cost
• Accuracy - measures interstitial fluid glucose so there may be a delay
• Acceptability

Question 15

Symptoms and signs of hypoglycaemia?

Answer 15

Night terrors/nightmares, sadness/crying spells, irritability

Headaches, faintness, hunger, confusion

Exhaustion/weakness

Vision problems

Anxiety/nervousness, hyperactivity, shaking, sweating

Digestive trouble

Question 16

Define severe hypoglycaemia?

Answer 16

Hypoglycaemic that leads to seizures, unconsciousness or the need for external assistance

Question 17

Link between HbA1c and hypoglycaemic?

Answer 17

As HbA1c decreases, patients have more hypoglycaemic episodes

Question 18

Immediate treatment and assessment of hypoglycaemic?

Answer 18

Consume 15-20g of glucose/simple carbohydrates and then recheck BG after 15 minutes

If hypoglycaemia continues, repeat measurement

Once BG returns to normal, eat a small snack if the next planned meal/snack if >1/2 hours away

Question 19

15 g of simple carbohydrates that are commonly used?

Answer 19

• Glucose tablets
• Gel tube
• 2 tablespoons of raisins
• 4 ounces (1/2 cup) of juice or regular coca-cola (not diet)
• 1 tablespoon sugar, honey, or corn syrup
• 8 ounces of non-fat or 1% milk
• Hard sweets, jellybeans, or gumdrops

Question 20

Treatment of severe hypogylcaemia?

Answer 20

Glucagon 1 mg injected into buttock/arm/thigh

When consciousness is regained (usually 5-15 minutes), they may have nausea and vomiting

Question 21

Describe impaired hypoglycaemia awareness (AKA hypoglycaemic unawareness)

Answer 21

Hypoglycaemic occurs (<4 mmol/L) but the individual feels no symptoms or no change in their symptoms

Occurs more frequently in those who:
• Frequently have low BG episodes
• Long duration T1DM/T2DM
• Intensively treated T1DM (low HbA1c)

Question 22

Normal counter-regulatory hormone response to hypoglycaemia?

Answer 22

Once BG drops to 3.8 mmol/L, stress hormones increase; for this reason, many hypoglycaemic episodes occur at night, as no stress hormones are produced

Question 23

When do symptoms and cognitive dysfunction of hypoglycaemia occur?

Answer 23

Symptoms - 3.0 mmol/L
Cognitive dysfunction - 2.8 mmol/L

4 IS THE FLOOR

Question 24

Patients in whom severe hypoglycaemia is more common?

Answer 24

• Age 2-6 years
• Non-hispanic black
• Lower annual household income and no private health insurance
• Longer duration diabetes
• Higher HbA1c
• MDI

Question 25

Effects of intensive treatment of diabetes on hypoglycaemia?

Answer 25

INTENSIVE treatment can impair the defence against hypoglycaemia

Question 26

What is hypoglycaemia-associated autonomic failure?

Answer 26

Maladaptive response to repeated hypoglycaemia

Iatrogenic hypoglycemia causes both defective glucose counter-regulation (by REDUCING ADRENALINE response to falling glucose levels in the setting of an ABSENT GLUCAGON response) and hypoglycemia unawareness

Question 27

What is impaired awareness of hypoglycaemic a risk factor for?

Answer 27

Severe hypoglycaemia

Question 28

Methods of avoiding hypoglycaemia?

Answer 28

1. Intensive insulin therapy:
• Structured education
• Hypoglycaemia
• Basal Insulin
• Re-education

2. Insulin analogues/CSII
   CGM
3. Cognitive Behavioural Therapy
4. Pancreas transplantation

Question 29

Rare contributors to hypoglycaemic risk?

Answer 29

Primary failure of hormones to raise glucose:
• Hypopituitarism
• Adrenal cortical failure (Addison’s disease)
• Isolated growth hormone deficiency

Prolongation of insulin effects:
• Exogenous injection
• Insulin secretagogues/ sensitisers
• Renal impairment
• Hypothyroidism
• Liver failure
• Insulin-binding antibodies
• Activating insulin receptor antibodies

Exaggerated mismatch between insulin and nutrient absorption:
• Malabsorption, e.g: coeliac disease (more common in T1DM)
• Delayed insulin administration

Lifestyle contributors:
• Acute increase in glucose uptake with exercise
• Depletion of liver glycogen with vigorous/prolonged exercise
• Alcohol suppression of gluconeogenesis