Diabetes Mellitus

Question 1

What is DM?

Answer 1

Polydipsia, polyuria and weight loss due to abnormally raised levels of blood glucose.

Question 2

Describe T1DM, usual presentation, cause.

Answer 2

Adolescent onset, polydipsia, polyuria, weight loss, ketosis.

Insulin deficiency from autoimmune destruction of insulin secretin pancreatic beat cells.
Patients must have insulin and are prone to ketoacidosis and weight loss.
Associated with other autoimmune diseases.

LADA is a form that occurs in adults with slower progression

Question 3

Describe type 2 usual presentation and cause.

Answer 3

Over 40 usually, Asians, men, elderly
Aymptomatic/complications

Associated with obesity, lack of exercise, calorie and alcohol excess. Reduced insulin secretion and insulin resistance.

MODY is a form that occurs in young people

Question 4

What is impaired glucose tolerance?

Answer 4

Fasting plasma glucose <7mmol/L and OGTT 2h glucose >7.8mmol/L but <11.1mmol/L

Question 5

What is impaired fasting glucose?

Answer 5

Fasting plasma glucose >6.1mmol/L but <7mmol/L

Do OGTT to exclude DM

Question 6

What is prediabetes?

Answer 6

This term is used for patients who don’t yet meet the criteria for a formal diagnosis of T2DM to be made but are likely to develop the condition over the next few years. They, therefore, require closer monitoring and lifestyle interventions such as weight loss

HbA1c 42-47
Fasting glucose 6.1-6.9mmol/L

Question 7

What is maturity onset diabetes of the young?

Answer 7

A group of inherited genetic disorders affecting the production of insulin. Results in younger patients developing symptoms similar to those with T2DM, i.e. asymptomatic hyperglycaemia with progression to more severe complications such as diabetic ketoacidosis

Autosomal dominant

Question 8

What is latent autoimmune diabetes of adults?

Answer 8

The majority of patients with autoimmune-related diabetes present younger in life. There are however a small group of patients who develop such problems later in life. These patients are often misdiagnosed as having T2DM

Question 9

What are other causes of diabetes?

Answer 9

Steroids
Pancreatitis
Pancreatic cancer

Cushings, acromegaly, phaeochromocytoma, hyperthyroidism pregnancy

Question 10

What is metabolic syndrome?

Answer 10

Central obesity (BMI>30) plus 22 of:
BP>130/85
Triglycerides >1.7mmol/L
HDL low
Fasting  > 5.6mmol/L
T2DM

Question 11

What are symptoms signs of diabetes? Diabetic ketoacidosis?

Answer 11

Hyperglycaemia:
Polyuria
Polydipsia
Weight loss 
Visual blurring
Genital thrush
Lethargy
Raised venous glucose detected

Diabetic acidosis:
Abdominal pain
Vomiting
Reduced consciousness

Question 12

What investigations for diabetes?

Answer 12

Fasting plasma glucose >7mmol/L
Random venous glucose > 11.1mmol/L
OGTT 2h glucose > 11.1mmol/L
HbA1c > 48mmol/L or 6.5%
HbA1c is amount of glycosylated haemoglobin - average blood glucose over 2-3 months

Question 13

What are the criteria for diagnosis of DM?

Answer 13

Symptoms of hyperglucaemia + raised venous glucose on 1 occasion

Raised venous glucose on 2 separate occasions

HbA1c 48mmol/L or more
Do not do HbA1c in pregnancy, children T1DM and anaemia

Question 14

Compare type 1 and type 2

Answer 14

T1:
Starts before puberty
Autoimmune metal cell destruction
Polydipsia, polyuria, weight loss, ketosis

T2:
Older patients
Insulin resistance/beta cell dysfunction
Asymptomatic/complications

Question 15

What is the diagnostic valve for fasting?

Answer 15

7mmol/L or more

Question 16

What is the diagnostic value for random glucose?

Answer 16

11.1 mmol/L or more

Question 17

What is the diagnostic value for OGTT?

Answer 17

11.1mmol/L or more

Question 18

What is the diagnostic value for HbA1c

Answer 18

48mmol/L or more

6.5%

Question 19

How is glucose control monitored?

Answer 19

Fingerprick glucose before meals for long sting insulin and after meals for short acting insulin

HbA1c - glucose over previous 8 weeks

hypoglycaemic attacks