Week 7 & 8: T2D Flashcards
What is T1D?
Type 1 D: often juvenile onset
- approximately 10% of diabetes cases
- onset occurs by age 20 usually
- idiopathic
- autoimmune destruction of beta cels
- treated with exogenous insulin
refer to week 7 lecture slide 71
What is T2D?
Type 2 D: usual onset greater than 40 years
- approx. 85-95% of diabetes cases
- increasing incidence of adoloscent cases
- characterised by insulin resistance
- treated by hypoglycaemic medication
- people with T2D for a long time often require exogenous insulin later in life
refer to week 7 lecture slide 71
How is T2D diagnosed?
- FPG ≥7.0 mmol/L
- Fasting = no caloric intake for at least 8 hours
or - HbA1C ≥6.5% (in adults)
- Using a standardized, validated assay, in the absence of factors that affect the accuracy of the A1C and not for suspected type 1 diabetes
or - 2hPG in a 75-g OGTT ≥11.1 mmol/L
or - Random PG ≥11.1 mmol/L
random = any time of the day, without regard to the interval since the last meal
2hPG = 2-hour plasma glucose; FPG = fasting plasma glucose; OGTT = oral glucose tolerance test; PG = plasma glucose
week 7 lecture slide 73
How are asymptomatic patients assesed to be at high risk of diabetes?
- Asymptomatic patients are those who are not diagnosed with diabetes but are assessed to be at high risk based on a risk score.
- There are two ways to test for diabetes:
- Fasting blood glucose (FBG)
- Hemoglobin A1c (HbA1c)
- The results of the tests are used to determine the likelihood of diabetes.
- If the initial test results are high, a confirmatory test with the other method (blood glucose or HbA1c) is needed.
- If the confirmatory test is negative, the patient should be retested in one year.
- If the confirmatory test is positive, the person is considered to have diabetes. HbA1c results less than 6.5% do not rule out diabetes.
week 7 lecture slide 74
What is OGTT?
Oral glucose tolerance test (OGTT) is used to diagnose diabetes.
Procedure:
Fasting blood sugar test
Drink a sugary solution
Blood sugar tests at intervals (e.g., 1, 2 hours)
Measures: Body’s ability to process sugar (glucose)
week 7 lecture slide 75
What are the blood sugar levels that indicate normal, impaired fasting glucose, and type 2 diabetes according to the OGTT?
Normal: ≤ 7.8 mmol/L at 2 hours
Impaired fasting glucose: > 7.8 mmol/L and < 11.1 mmol/L at 2 hours
Type 2 diabetes: ≥ 11.1 mmol/L at 2 hours
week 7 lecture slide 75
What is the prevalence of T2D in men and women?
- greater prevalence in men and women 75+ years
- Men have increased prevalence compared to women 55-75+
week 7 lecture slide 76
What is the burden of hospitalisation for T1D and T2D?
source: AIHW National Hospital Morbidity Base, Figure 1 showing hospitalisations by diabetes type, 2015-2016
- Type 2 Diabetes: Most frequent hospitalization cause among diabetes types (63%).
- Additional Diagnosis: Highest hospitalization rate (90%) for patients with both diagnosed type 1 or 2 diabetes and another condition.
- Type 1 Diabetes: Lower hospitalization rate (29%) compared to type 2.
- Gestational Diabetes & Other: Lowest hospitalization rate compared to other types.
week 7 slide 77
What are the hospitalization Rates for Type 2 Diabetes by Age?
source: AIHW National Hospital Morbidity Base, Figure 1 showing hospitalisations by age, 2015-2016
- The graph shows hospitalisation rates per 100,000 people for Type 2 Diabetes.
- Generally, hospitalization rates increase with age for both males and females
- males have increased hospitalised to a higher extent than females with age
week 7 slide 78
What are the hospitalization Rates by Region and Socioeconomic Status (SES)?
source: AIHW National Hospital Morbidity Base, Figure 1 showing hospitalisations by region and SES, 2015-2016
- females in remote/very remoteregions had highest hospitalisation rate
- male in major cities, inner and outer regional areas had higher hospitalisation rates than females
- across the lowest and highest SES groups, males had higher hopspitalisation rates than females
refer to week 7 lecture slide 79
What happens in blood glucose homeostasis?
- The body tightly regulates blood sugar (glucose) levels for energy.
- Process:
- Liver stores glucose as glycogen (when high)
- Liver releases glucose (when low)
- Pancreas releases insulin (low blood sugar) - promotes glucose uptake into cells
- Pancreas releases glucagon (high blood sugar) - promotes glycogen breakdown and glucose release from liver
- Importance: Maintains energy for cells, prevents blood sugar from getting too high or too low (dangerous).
slide 81 lecture week 7
The liver plays a central role in regulating blood sugar levels.
When blood sugar rises (hyperglycemia), the liver converts glucose into glycogen, a storage form of glucose, for later use.
The pancreas releases insulin, a hormone that signals cells to absorb glucose from the bloodstream, lowering blood sugar levels.
When blood sugar falls (hypoglycemia), the liver breaks down glycogen back into glucose to release it into the bloodstream, raising blood sugar levels.
Glucagon, another hormone produced by the pancreas, stimulates the liver to convert glycogen into glucose when blood sugar is low.
The body maintains a delicate balance between these processes to ensure blood sugar levels stay within a healthy range.
Factors Affecting Insulin Secretion and Action
Positive factors that increase insulin secretion and action:
- Increased physical activity
- Normal body weight
Negative factors that decrease insulin secretion and action:
- Heavy alcohol consumption
- Smoking
- Genetic predisposition (genes)
- Gestational diabetes
- Epigenetics (environmental influences on genes)
Consequences:
- Hyperglycemia (high blood sugar) –> Long-term damage to nerves, eyes, kidneys
- Insulin resistance (Cells become less responsive to insulin)
- B-cell dysfunction (impaired insulin secretion)
slide 82 lecture week 7
summary of effects of T2D on body systems and organs
slide 83 lecture week 7
COME BACK TO THIS SLIDE .. do i even need it vcayse slide 85 talks about exact same thing
Effects of Insulin Resistance
Increased:
- Glycogenolysis & Gluconeogenesis (↑ glucose output, ↓ storage)
Reduced:
- Muscle glucose transport (↓ uptake & storage)
- Glucose uptake (↓ uptake & storage)
- Lipolysis (↑ FFA release into blood)
Pancreas:
- Initially ↑ insulin output (to overcome resistance)
- Over time, ↓ insulin secretion (worsens blood sugar control)
refer to slide 85 of week 7 lecture
How does insulin reduce blood glucose?
Its effect on liver:
- Store glucose as glycogen
- Turn off gluconeogenesis
Its effect on muscle:
- Increase glucose transport to reduce blood glucose
- Increase storage as glycogen to reduce blood glucose
Its effect on fat cells:
- Increase glucose transport
- Turn off hormone sensitive lipase (the enzyme that breaks down stored fat)
refer to slide 85 of week 7 lecture
Individualizing HbA1c Targets
Most patients with type 1 or 2 diabetes should aim for HbA1c ≤7%
Consider higher targets (up to 8.5%) for:
* Limited life expectancy
* High functional dependency
* Extensive coronary artery disease
* Multiple co-morbidities
* History of recurrent severe hypoglycemia
* Longstanding diabetes with difficulty achieving HbA1c ≤7% despite treatment
Consider lower targets (down to 6.5%) for:
* Some patients with type 2 diabetes to lower risk of nephropathy and retinopathy
Balancing benefits and risks is important (e.g., tighter control may increase risk of hypoglycemia)
refer to slide 88 of week 7 lecture
Make an exhaustive list of the parmacological treatment of type 2 diabetes (based on the lectures)
- biguanides
- alpha glucosidase inhibitors
- DPP -4 inhibitors
- sulphonylureas
- meglitinides
- thiaszolidinediones
- glucagon like peptide 1 (GLP-!) receptor agonists)
use this when oral hypoglycaemics fail
* short acting insulin
* long acting insulin
* incretin mimetics
refer to slide 89 - 92 of week 7 lecture
What are biguanides
Biguanides (Glucophage, Metformin, diaformin, diabex)
- – First line treatment for diabetes
– Sometimes used to prevent diabetes (US DPP)
– Primary effect is to sensitize liver to insulin – reduces glycogenolysis and gluconeogenesis
– Does not cause weight gain, can cause some weight loss
– Minimal risk of hypoglycaemia
week 7 lecture slide 89
What are alpha glucosidase inhibitors
α-glucosidase inhibitors (Acarbose, glucobay)
- – Slow digestion and absorption of carbohydrates
– On it’s own, does not cause hypoglycaemia, but if it does occur due to other medication, treatment must be
with glucose
week 7 lecture slide 89
What are DPP -4 inhibotrs
DPP-4 inhibitors (Linagliptin, Sinagliptin, Januvia, Trajenta)
- – On their own do not cause hypoglycaemia, but risk is elevated if treated together with a sulphonylurea
– Stimulate incretin secretion which in turn stimulates insulin secretion from the pancreas
week 7 lecture slide 89
What are sulphonylureas
Sulphonylureas (Gliclazide, glimepride, diamicron)
– Insulin secretagogue; Lower blood glucose by stimulating insulin release from the pancreas
– Can cause weight gain
– Can cause hypoglycaemia
week 7 lecture slide 90