**_🧪Endocrinology🧪 - Type 2 Diabetes Mellitus Flashcards

1
Q

Define type 2 diabetes

A

Condition in which the combination of insulin resistance and beta-cell failure results in hyperglycaemia

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2
Q

Explain type 2 diabetes

A

A person who has large amounts of visceral adipose tissue, and continuously high blood glucose (usually due to foods with high sugar content) will have their cells become insulin resistant. This means more insulin is required. Beta-cells can match this demand as it increases and so pump out more and more insulin, to a point. Then they begin to fail, and so the combination of insulin resistance increasing and less insulin being able to be produced leads to type 2 diabetes

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3
Q

What condition is T2DM usually associated with?

A

Obesity (usually, but not always)

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4
Q

How is T2DM managed?

A

Changes to diet/weight loss
May even be reversible in early stages
With time, glucose lowering therapy and insulin may be needed

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5
Q

When does T2DM present?

A

Typically in older people, but can present in youth/young adults

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6
Q

Is DKA a sign of T1/T2DM?

A

Usually T1, much more common in T1
Possible in T2 however

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7
Q

What are the current epidemiological trends for T2DM?

A

Varies enormously between countries/regions
Increasing prevalence
Occurring and being diagnosed younger
Greatest in ethnic groups moving from rural to urban lifestyles

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8
Q

What are the parameters for glucose blood tests in the normal range?

A

Fasting glucose levels <6mmol/L
2hr glucose (DGTT) <7.7mmol/L
HbA1c <42mmol/mol

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8
Q

What is the range of values for glucose blood tests showing intermediate state of diabetic development

A

6 < Fasting glucose levels < 7
7.7 < 2hr glucose (DGTT) < 11
42 < HbA1c < 48

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9
Q

What values in glucose blood tests would indicate a diagnosis of T2DM?

A

Fasting glucose >7mmol/L
2-hr glucose (DGTT) >11mmol/L
HbA1c >48mmol/mol

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10
Q

How does DKA usually not arise in T2DM?

A

Insulin is still produced, but there is increased resistance
It is a relative insulin deficieny
Insulin inhibits production of ketone bodies (lack of insulin in T1DM, so no inhibition of ketone body formation)

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11
Q

When can T2DM lead to DKA?

A

In T2DM, there is continuous decline in beta-cell function until total failure
Then there is a lack of insulin, leading to the chain of events that causes DKA

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12
Q

Briefly outline the pathophysiology of T2DM

A

Genes and intrauterine+adult environments
Insulin resistance and eventually insulin secretion defects
Fatty acids important in pathogenesis

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13
Q

How does hyperglycaemia occur in T2DM?

A

Reduced insulin action leads to less uptake of glucose into skeletal muscle
Lack of insulin action leads to increased hepatic glucose production (and increased glucagon action)

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14
Q

What is the consequence of insulin resistance in adipose tissue?

A

Less inhibition of lipolysis (i.e. more lipolysis)
Results in the release of NEFAs

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15
Q

What are the 2 genetic forms of diabetes?

A

Monogenic - single gene mutation
MODY, “born with it, development of diabetes is inevitable”
Polygenic - many mutations
Polymorphisms increase risk - “not born with, but increased risk later depending on environment”

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16
Q

What effect do SNPs (single nucleotide polymorphisms) have on the risk of diabetes?

A

Individual SNPs have mild effect on risk
Many SNPs can have a cumulative significant effect on risk

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17
Q

What is the role of obesity in T2DM?

A

Major risk factor for T2DM
80% T2DM sufferers are obese
Fatty acids and adipocytokines play significant role
Weight reduction is effective treatment

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18
Q

What is the role of adipocytokines in the pathogenesis of T2DM?

A

They contribute to insulin resistance and chronic inflammation

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19
Q

What is the role of NEFAs in the pathogenesis of T2DM?

A

Impair insulin signalling in the liver, promote lipotoxicity in beta-cells
Overall, both impairs insulin secretion and promotes insulin resistance

20
Q

What other factors are associated (albeit less firmly) with T2DM?

A

Perturbations in gut microbiota
Intra-uterine growth retardation (underweight at birth)

21
Q

How does T2DM present?

A

Hyperglycaemia
Overweight
Dyslipidaemia (from NEFAs)
Fewer osmotic symptoms (i.e. less dramatic urine symptoms)

22
Q

What are the biggest risk factors for T2DM?

A

Age
PCOS
High BMI
Family History
Ethnicity
Inactivity

23
Q

What can be used to diagnose T2DM?

A

Osmotic symptoms (less pronounced that T1DM)
Infections (particularly UTIs)
Presentation of compication:
Acute - hyperosmolar hyperglycaemic state
Chronic - Ischaemic heart disease, retinopathy

24
Q

Why are UTIs commonly associated with diabetes?

A

Glycosuria means there is a glucose rich urinary tract
Provides nutrient-rich environment for bacteria and fungi (e.g. yeast infections)

25
Q

What is a hyperosmolar hyperglycaemic state?

A

Insulin deficiency resulting in dehydration and hyperosmolality
Deficiency not absence of insulin - still enough to prevent lipolysis and ketogenesis

26
Q

How does a hyperosmolar hyperglycaemic state present?

A

Hyperglycaemia
Osmotic diuresis leading to dehydration
Often an identifiable precipitating event (e.g. infection)

27
Q

What is the management of T1DM?

A

Exogenous insulin (basal-bolus regime)
Self-monitoring of glucose
Structured education
Technology

28
Q

Outline the management of T2DM

A

Diet
Oral medication
Structured education
May need insulin later
Remission / reversal is the target

29
Q

What are the main diabetes-related long term complications that we are aiming to avoid?

A

Retinopathy
Neuropathy
Nephropathy
Cardiovascular complications (e.g. atherosclerosis)

30
Q

What are the principles of a T2DM consultation?

A

Monitor glycaemia: HbA1c, glucose monitoring (if on insulin), followed by medication review
Weight assessment + blood pressure
Dyslipidaemia: monitor with a cholesterol profile
Screening for remaining complications: foot check, retinal screening

31
Q

What are the overall diet recommendations for T2DM?

A

Total calories control
Reduce calories as fat
Reduce calories as refined carbohydrate
Increase calories as complex carbohydrate
Increase soluble fibre
Decrease sodium (prevent hypertension)

32
Q

What are the main facets of the pathophysiology of T2DM?
(Recap)

A

Excess hepatic glucose production
Resistance to action of circulating insulin
Inadequate insulin production for extent of insulin resistance
Excess glucose in circulation

33
Q

What is the strategy and solution for excess hepatic glucose production?

A

Reduce hepatic glucose production
Metformin

34
Q

What is the strategy and solution for resistance to action of insulin?

A

Improve insulin sensitivity
Metformin/Thiazolidinediones

35
Q

What is the strategy and solution for inadequate insulin production to accommodate resistance?

A

Boost insulin secretion
Sulphonylureas, DPP-4 inhibitors, GLP-1 agonists

36
Q

What is the strategy and solution for excess glucose in circulation?

A

Inhibit carbohydrate gut absorption - alpha glucosidase inhibitor
Inhibit renal glucose reabsorption - SGLT-2 inhibitor

37
Q

Outline metformin:
Function
Side effects
Contraindications

A

Insulin sensitiser, biguanide
First line treatment if dietary/lifestyle not enough
Reduces insulin resistance - reduced hepatic glucose output, increases peripheral glucose disposal
GI side effects
Contraindicated in sever liver, cardiac or moderate renal failur

38
Q

What is the mechanism of action of Sulphonylureas?

A

Block potassium channel in beta-cells (independent of ATP or glucose) allowing continuous insulin secretion

39
Q

Outline Pioglitazone

A

Insulin sensitiser, particularly peripherally
Adipocyte differentiation modified - weight gain (peripheral, not central)
Improvement in glycaemia and lipids
Side effects of older types hepatitis, heart failure

40
Q

Which glucose lowering therapies can cause weight gain?

A

All except metformin on its own

41
Q

Outline GLP-1

A

Glucagon like peptide-1 - gut hormone
Secreted in response to nutrients in gut
Produced by L-cells
Stimulates insulin, suppresses glucagon
Causes satiety
Used in treatment of diabetes mellitus
Short half life due to rapid degradation by dipeptidyl peptidase-4 (hence relevance of DPP-4 inhibitor)

42
Q

Outline GLP-1 agonists

A

Liraglutide, Semaglutide
Injectable –daily, weekly
Decrease glucagon
Decrease glucose
Weight loss

43
Q

Outline DPP-4 inhibitors

A

Increase half life of exogenous GLP-1
Increase GLP-1
Decrease glucagon
Decrease glucose
Neutral on weight

44
Q

Outline SGLT-2 inhibitors

A

Inhibits Na-Glu transporter, increases glycosuria
Empagliflozin, dapagliflozin, canagliflozin
HbA1c lower
32% lower all cause mortality
35% lower risk heart failure
Improves CKD

45
Q

What are 2 methods that are used to induce remission of T2DM?

A

Gastric bypass surgery
Very low calorie diet (800kcal/day)

46
Q

What are the other aspects of T2DM that need to be managed?

A

Blood pressure
Dyslipidaemia

47
Q

Outline the impact of blood pressure in T2DM

A

Hypertension very common in T2DM
Clear benefits with reduction in BP, especially with use of ACE-inhibitors

48
Q

Outline the impact of dyslipidaemia in T2DM

A

Total cholesterol raised
Triglycerides raised
HDL cholesterol reduced
Clear benefit to lipid-lowering therapy (particularly in terms of CVD and vascular complications)