Week 7 - Diabetes

Question 1

Type 1 diabetes

Answer 1

pancreatic beta-cells stop producing insulin (due to T-cells attacking pancreatic beta-cells) therefore preventing glucose uptake into the cell

10% of diabetics

sudden onset at any age but usually in people <18yrs

Question 2

What does insulin deficiency lead to?

Answer 2

1) Increased hepatic glucose production to meet brain and energetic demands
2) Reduced uptake of glucose in peripheral tissues

Question 3

Diabetic ketoacidosis

Answer 3

It’s the most common hyperglycaemic emergency in people with diabetes (T1).

Insulin deficiency leads to hyperglycaemia. High levels of counter-regulatory hormones (glucagon, catecholamines) lead to increased lipolysis (release of free fatty acids).

Free fatty acids oxidized in the liver to ketones and the accumulation of ketoacids decreases bicarbonate levels which leads to the development of metabolic acidosis.

Question 4

3 types of diabetes

Answer 4

Type 1
Type 2
Gestational diabetes (occurs in pregnancy)

Question 5

Type 2 diabetes

Answer 5

is where receptors on peripheral tissues are not sensitive to insulin produced (insulin resistance), so glucose doesn’t translocate into the cell (characterised by hyperglycaemia)

90% of diabetics

Question 6

T1D: Signs and Symptoms

Answer 6

Weight loss
Frequent Urination
Irritability
Blurry vision
Fruity breath

Question 7

T2D: Signs and Symptoms

Answer 7

Weight loss
Excessive Thirst
Unceasing hunger
Headaches
Dry mouth

Question 8

What are the 3 most prevalent diabetes-related complications?

Answer 8

Chronic Kidney disease
Foot problems
Eye damage

Question 9

What blood glucose levels would indicate diabetes, pre-diabetes and normal at fasting and at post-prandial?

Answer 9

Fasting
- Diabetes: above 7
- Pre-diabetes: 5.6-7
- Normal: 3.9-5.5

Post-prandial
- Diabetes: Above 11
- Pre-diabetes: 9-10.9
- Normal: 3.9-8.9

Question 10

What are the strengths and weaknesses of using Hemoglobin A1c test (how much glucose is attached to RBC/hemoglobin) to diagnose diabetes?

Answer 10

Strength
- Not affected by one meal so more reliable measure
- Measures average blood glucose over 2-3months
- Suitable for T2D as they don’t often have low levels, usually always high.

Weakness
- Not suited to T1D as you can’t see day-to-day variability and they have both high/low blood glucose as they control their own insulin (injections) so this test doesn’t reflect their condition.
- As it’s an average, it doesn’t account for the different blood glucose ranges each day (could have spent lots of time below/above blood glucose range and still have a good HbA1c)

Question 11

What does a HbA1c score of … indicate?

a) in target
b) pre-diabetes
c) T2D

Answer 11

a) <42
b) 42-28
c) >48

Question 12

Oral glucose tolerance test

Answer 12

sugary drink consumed and then blood is taken to measure glucose levels
T2D have a large increase in glucose as their body isn’t respondent to insulin, this results in more insulin being release (creates a vicious cycle).

Question 13

Glucose clamp

Answer 13

insulin and glucose are infused and adjusted until the glucose infusion rate is equal to glucose uptake achieving a steady state

Insulin sensitivity measured by divided glucose disposal rate by steady-state blood glucose concentration x difference between fasting and steady-state plasma insulin

Question 14

In a C-peptide test, what are the ranges for low, normal and high. How is this used to diagnose diabetes?

Answer 14

Low C-peptide: <0.51ng/ml –> with high blood glucose levels = T1D

Normal C-peptide: 0.51-2.72 ng/ml

High C-peptide: >2.72ng/ml –> with high blood glucose levels = T2D

Question 15

How can classify pre-diabetes?

Answer 15

HbA1c >42mmol/mol
Fasting plasma glucose level 5.6-6.9mmol/L
2hr post-meal plasma glucose level 7.8-11mmol/L

Question 16

How can we classify T2D?

Answer 16

HbA1c >48mmol/mol
Fasting plasma glucose level >7mmol/L
2hr post-meal plasma glucose level >11mmol/L
Classic symptoms + random plasma glucose levels >11mol/L

Question 17

Less than ..% of adults with T2D achieve the activity guidelines.

Answer 17

40%

Question 18

3 internal barriers to exercise for people with T2D

Answer 18

1) Exercise isn’t motivating (lack of time, not interesting, uncomfortable)
2) Health problems (physical + mental)
3) Emotions (shame, laziness, stressful life situations, fear)

Question 19

4 external barriers to exercise for people with T2D

Answer 19

1) Lack of social support (lack of acceptance, lack of knowledge)
2) Lack of facilities to exercise (unsafe local facilities, lack of transportation, cost, poor local facilities)
3) Cultural barriers (religious and cultural barriers)
4) Weather

Question 20

Acute responses of the pancreas and liver to a bout of exercise.

Answer 20

Pancreas: decrease insulin secretion + increase glucagon secretion

Liver: increase glucose release

Question 21

What happens to insulin sensitivity after exercise?

Answer 21

Insulin sensitivity enhanced for up to 2 days after exercise.

Question 22

… association between MET h/week and reduced risk for T2D

Answer 22

Linear

• 150mins of moderate physical activity = 26% lower risk of developing T2D. 300min/week = 36% reduction in T2D (Schellenberg, 2013)
• The more you do the better: greater reduction in HbA1c in >150mins (Umpierre, 2011)

Question 23

Does the exercise intensity influence the improvements in T2D characteristics?

Answer 23

Finding 1: exercise prescription that incorporates 170min of exercise/week improved insulin sensitivity regardless of intensity (Umpierre, 2013)

Finding 2: Higher intensity elicits greater reductions in HbA1c but improvements also seen at lower intensities (Liubaoerjijin)

HIIT (high-intensity interval training) deemed more enjoyable than MICT (moderate intensity continuous training).

Question 24

When prescribing exercise for T2D, does the type of exercise matter?

Answer 24

HbA1c reduced in aerobic, resistance and combined training (Umpierre, 2011).

Question 25

When prescribing exercise for T2D, what is the recommended frequency of exercise?

Answer 25

Aerobic - at least 3 days/week
Resistance - twice weekly

Question 26

What is the “normal” hormonal counter regulation against hypoglycemia?

Answer 26

• Decreased insulin secretion
• Increased glucagon secretion
• Increased catecholamine secretion and sympathetic activation

Question 27

Barriers to exercise for people with newly diagnosed T1D

Answer 27

• Hypoglycaemia (actual and fear of)
• Lack of knowledge/confidence in managing diabetes
• Advice from healthcare professionals to stop exercising
• Planning (e.g. checking blood glucose)
• Feeling overwhelmed with diagnosis

Question 28

Barriers to exercise for people with T1D (established)

Answer 28

• Loss of control
• Lack of knowledge on the management of diabetes for exercise

Question 29

What are 5 key considerations to improve glycemia for exercise in T1D?

Answer 29

1) Know the type, duration and intensity of exercise
2) Check glucose and trend arrows
3) Consider timing of exercise
4) Know how much insulin on board
5) Take carbs if needed

Question 30

Explain the different effects of aerobic and resistance exercise on glucose levels during and after exercise.

Answer 30

During: resistance exercise results in much smaller declines in blood glucose than aerobic exercise.

After: resistance exercise associated with relatively stable post-exercise glucose whereas aerobic exercise associated with greater increases in glucose levels during early recovery

Question 31

Blood glucose was significantly increased above rest 1hr after one and two sets of resistance exercise. How does a 3rd set effect this? (Turner, 2015)

Answer 31

A third set attenuated the exercise induced hyperglycaemia and returned blood glucose levels to those of a control trial.

Question 32

What order should T1D perform resistance and aerobic exercise?

Answer 32

Perform resistance exercise first if they tend to develop exercise-associated hypoglycaemia. This order can reduce the reliance on glucose supplementation during exercise and might also decrease the severity of post-exercise hypoglycaemia.

Question 33

For T1D, is it better to exercise in the morning or afternoon? Why?

Answer 33

Morning –> fewer hypoglycaemic events.

Exercise in the morning improves metabolic control on the subsequent day and maintains patients in the euglycemic range for a longer time.

Question 34

For T1D, how does Intermittent High intensity exercise (IHE) compare to moderate exercise?

Answer 34

the decline in blood glucose is less with IHE compared to moderate exercise during both exercise and early recovery (reduced hypoglycaemia risk)

Question 35

What do we expect to happen to blood glucose during short, intense activities and during aerobic activities?

Answer 35

Short, intense activities (weightlifting): increase blood glucose due to adrenaline stimulating glucose release from liver

Aerobic activities: decrease blood glucose due to glucose uptake (AMPK)

Question 36

Risk of submaximal exercise and intermitten high intensity exercise in T1D.

Answer 36

nocturnal hypoglycaemia

Question 37

If we expect glucose to drop during low/moderate aerobic exercise, what should T1 diabetics do?

Answer 37

reduce their mealtime insulin
-25% for mild aerobic exercise
-50% for moderate
-75% for intense

Carbohydrate snack (e.g. if blood glucose <5.6 take 20g of carbs)

Question 38

Carbohydrate requirements are based on body weight. For moderate activity and intense activity how much is recommended?

Answer 38

Moderate: 0.5g/kg/hr
Intense: 1g/kg/hr

Question 39

If blood glucose is high, what exercise should we start with?

Answer 39

aerobic then anaerobic

Question 40

If glucose is low, what exercise should we start with?

Answer 40

anaerobic then aerobic

Question 41

What are the general recommendations for carb intake for exercise?

Answer 41

30g per hour
divide carbs over an hour
small snacks every 20mins

Question 42

How may continuous exercise and sprints be more appropriate for T1 diabetics than continuous exercise alone?

Answer 42

Continuous exercise will result in a steady decrease in blood glucose.

Sprints with continuous exercise will increase blood glucose (sprint) and then reduce blood glucose (continuous), and so on… This prevents blood glucose going too high or too low (goes up and down).