Week 7 - Diabetes Flashcards
(42 cards)
Type 1 diabetes
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
What does insulin deficiency lead to?
1) Increased hepatic glucose production to meet brain and energetic demands
2) Reduced uptake of glucose in peripheral tissues
Diabetic ketoacidosis
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.
3 types of diabetes
Type 1
Type 2
Gestational diabetes (occurs in pregnancy)
Type 2 diabetes
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
T1D: Signs and Symptoms
Weight loss
Frequent Urination
Irritability
Blurry vision
Fruity breath
T2D: Signs and Symptoms
Weight loss
Excessive Thirst
Unceasing hunger
Headaches
Dry mouth
What are the 3 most prevalent diabetes-related complications?
Chronic Kidney disease
Foot problems
Eye damage
What blood glucose levels would indicate diabetes, pre-diabetes and normal at fasting and at post-prandial?
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
What are the strengths and weaknesses of using Hemoglobin A1c test (how much glucose is attached to RBC/hemoglobin) to diagnose diabetes?
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)
What does a HbA1c score of … indicate?
a) in target
b) pre-diabetes
c) T2D
a) <42
b) 42-28
c) >48
Oral glucose tolerance test
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).
Glucose clamp
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
In a C-peptide test, what are the ranges for low, normal and high. How is this used to diagnose diabetes?
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
How can classify pre-diabetes?
HbA1c >42mmol/mol
Fasting plasma glucose level 5.6-6.9mmol/L
2hr post-meal plasma glucose level 7.8-11mmol/L
How can we classify T2D?
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
Less than ..% of adults with T2D achieve the activity guidelines.
40%
3 internal barriers to exercise for people with T2D
1) Exercise isn’t motivating (lack of time, not interesting, uncomfortable)
2) Health problems (physical + mental)
3) Emotions (shame, laziness, stressful life situations, fear)
4 external barriers to exercise for people with T2D
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
Acute responses of the pancreas and liver to a bout of exercise.
Pancreas: decrease insulin secretion + increase glucagon secretion
Liver: increase glucose release
What happens to insulin sensitivity after exercise?
Insulin sensitivity enhanced for up to 2 days after exercise.
… association between MET h/week and reduced risk for T2D
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)
Does the exercise intensity influence the improvements in T2D characteristics?
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).
When prescribing exercise for T2D, does the type of exercise matter?
HbA1c reduced in aerobic, resistance and combined training (Umpierre, 2011).
