Case 5 - Type 2 Diabetes

Question 1

What is prediabetes?

Answer 1

Prediabetes is not a clinical term recognised by the World Health Organisation (WHO). But it is starting to be used more by healthcare professionals and in the media to describe people who are at high risk of type 2 diabetes. Prediabetes means higher than usual blood glucose levels, but not high enough to be diagnosed with type 2 diabetes. Some patients may not be experience any symptoms with prediabetes.

Question 2

How can prediabetes be tested?

Answer 2

Prediabetes is usually tested using a blood test. The test checks HbA1C levels, meaning average blood glucose (sugar) levels for the last two to three months. The target range, for those at risk of developing type 2 diabetes, should be a HbA1C level should be below 42mmol/mol (6%).

Question 3

How does weight affect risk of type 2 diabetes?

Answer 3

Those carrying extra weight are at a high risk of type 2 diabetes. However, losing just 5% of body weight can significantly reduce the risk.

Question 4

How does diet affect risk of type 2 diabetes?

Answer 4

Risk of type 2 diabetes increases if a diet composed of food and drinks with high fat, high glycemic index (GI) and low fibre. Healthy diets should include foods linked with a decreased risk, like: fruit and veg, wholegrains, yogurt and cheese, and unsweetened tea and coffee. Foods that should be cut down on include: red and processed meat, refined carbohydrates, sugar sweetened drinks and potatoes (chips and crisps).

Question 5

How does exercise affect risk of type 2 diabetes?

Answer 5

A sedentary lifestyle has been linked with an increased risk of type 2 diabetes. Staying active in daily life can help to reduce risk of type 2 diabetes.

Question 6

What is the NHS Diabetes Prevention Programme?

Answer 6

The NHS Diabetes Prevention Programme (NHS DPP) is a joint commitment from NHS England, Public Health England and Diabetes UK, to deliver at scale, evidence based behavioural interventions for individuals identified as being at high risk of developing Type 2 diabetes.

Question 7

What percentage of the NHS budget does diabetes treatment account for?

Answer 7

Diabetes treatment currently accounts for around 10% of the annual NHS budget.

Question 8

What are the long term aims of the NHS DPP?

Answer 8

1) To reduce the incidence of Type 2 diabetes
2) To reduce the incidence of complications associated with diabetes - heart, stroke, kidney, eye and foot problems related to diabetes
3) To reduce health inequalities associated with incidence of diabetes

Question 9

What is the short term aim of the NHS DPP?

Answer 9

A stronger focus on identifying people who are at risk of diabetes, which is likely to increase incidence of diabetes as more undiagnosed cases are uncovered.

Question 10

What are the 3 core values of the NHS DPP behavioural intervention?

Answer 10

The NHS DPP behavioural intervention is underpinned by three core goals:

1) Achieving a healthy weight
2) Achievement of dietary recommendations
3) Achievement of CMO physical activity recommendations

Question 11

How is the NHS DPP structured?

Answer 11

The programme must be made up of at least 13 sessions, with at least 16 hours face to face contact time, spread across a minimum of 9 months, with each session lasting between 1 and 2 hours.

Question 12

Who is eligible for the NHS DPP?

Answer 12

1) Individuals who have ‘non-diabetic hyperglycaemia’ (NDH), defined as having an HbA1c 42 – 47 mmol/mol (6.0 – 6.4%) or a fasting plasma glucose (FPG) of 5.5 – 6.9 mmol/l.
2) The blood result indicating NDH must be within the last 12 months.
3) Only individuals aged 18 years or over are eligible.

Question 13

What are the 3 referall routes into the NHS DPP?

Answer 13

1) Those who have already been identified as having an appropriately
elevated risk level (HbA1c or FPG) in the past and who have been
included on a register of patients with high HbA1c or FPG;
2) The NHS Health Check programme, which is currently available for
individuals between 40 and 74. NHS Health Checks includes a diabetes
filter, those identified to be at high risk through stage 1 of the filter are
offered a blood test to confirm risk; and
3) Those who are identified with non-diabetic hyperglycemia through
opportunistic assessment as part of routine clinical care.

Question 14

What are the core pathogenic defects in type 2 diabetes?

Answer 14

Insulin resistance in muscle and the liver, and impaired insulin secretion by the pancreatic β-cells are the core defects in type 2 diabetes mellitus (T2DM).

Question 15

What causes failure in the function of β-cells?

Answer 15

β-cell resistance to the incretin ‘glucagon-like peptide 1’ (GLP1) contributes to progressive failure in the function of β-cells.

Question 16

What causes excessive glucose production by the liver?

Answer 16

Increased glucagon levels and enhanced hepatic sensitivity to glucagon contribute to the excessive glucose production by the liver.

Question 17

What causes insulin resistance in muscle and liver cells?

Answer 17

Insulin resistance in adipocytes results in accelerated lipolysis and increased plasma free fatty acid (FFA) levels, both of which aggravate the insulin resistance in muscle and the liver and contribute to β-cell failure.

Question 18

How is hyperglycaemia maintained?

Answer 18

Increased renal glucose reabsorption by the sodium/glucose co-transporter 2 (SGLT2) and the increased threshold for glucose spillage in the urine contribute to the maintenance of hyperglycaemia.

Question 19

What causes weight gain?

Answer 19

Resistance to the appetite-suppressive effects of a number of hormones, as well as low brain dopamine and increased brain serotonin levels contribute to weight gain, which exacerbates the underlying resistance.

Question 20

What is the “ominous octet”?

Answer 20

These are the 8 different defects in sugar metabolism in type 2 diabetes:

1) Decreased insulin secretion
2) Increased glucagon secretion
3) Decreases incretin effect
4) increased lipolysis
5) Increased glucose reabsorption in the kidneys
6) Decreased glucose uptake by muscles
7) Neurotransmitter dysfunction
8) Increased hepatic glucose production

Question 21

What is the “decadent decoplet”?

Answer 21

This includes the “ominous octet”, with vascular insulin resistance and inflammation added.

Question 22

What causes impaired insulin secretion in T2DM?

Answer 22

This is caused by pancreatic beta-cells dysfunctioning, owing to lipotoxicity, glucotoxicity and resistance to incretins (intestinal hormones that stimulate insulin secretion). Peripheral hormones (e.g. kidneys, liver and muscle) become insulin resistant, leading to reduced glucose uptake from blood, excessive glucose reabsorption by the kidney and increased gluconeogenesis, leading to hyperglycaemia.

Question 23

What are the different causes of insulin resistance?

Answer 23

1) Genetic abnormalities
2) Ectopic lipid accumulation
3) Mitochondrial dysfunction
4) Inflammation
5) Endoplasmic reticulum stress

Question 24

What determines the severity of microvascular complications?

Answer 24

The severity and duration of hyperglycaemia determines the risk of microvascular complications such as, retinopathy, nephropathy and neuropathy.

Question 25

What macrovascular complications are associated with T2DM?

Answer 25

Macrovascular complications usually result from dislipidaemia, hypertension, hyperglycaemia and inflammation, and include:

1) Myocardial infarction
2) Peripheral vascular disease
3) Stroke

Question 26

What is the single most important risk factor for T2DM?

Answer 26

A BMI >25 is the single most important risk factor, however the prevalence of T2DM has increased dramatically in China and India, despite the low prevalence of obesity. This may be explained by different fat-versus-muscle-mass ratios, different fat tissue distribution and a greater severity of beta-cell failure.

Question 27

What is the initial medication used to treat T2DM?

Answer 27

Metformin is generally the preferred initial medication for treating type 2 diabetes, unless there’s a specific reason not to use it, as it allows the body to better respond to insulin and decreases hepatic glucose output (HGO). Metformin is effective, safe as it does not cause hypoglycaemia, inexpensive and does not cause weight gain, unlike other diabetes medications. Serious side effects from metformin are exceedingly rare, occurring only in 1 in 10,000 people.