Endocrinology and Diabetes

Question 1

DIABETES MELLITUS: Describe the diagnostic criteria for diabetes mellitus and glucose intolerance with reference to laboratory glucose and HBA1c measurement.

Answer 1

Question 2

DIABETES MELLITUS: Understand the aetiological classification of diabetes mellitus including the usual presentations of type 1 and type 2 diabetes.

Answer 2

Aetiological classification:

• Beta cell destruction - with absolute insulin deficiency
• Insulin resistance or insulin secretion defect
• Gestational diabetes

​Presentation of type 1 and 2 DM

Type 1 DM

• Generally younger pts
• Polydipsia, polyuria, weight loss, fatigue, recurrent infections (e.g. candida)
• Can be diagnosed following presentation with hyperglycaemia (random plasma glucose >11.1) with or without clinical signs. Following diagnosis referral to a specialist diabetes team should be made on the same day

Type 2 DM

• Generally obese pts, older age group
• May be asymmptomatic or present with symptoms similar to type 1
• Diagnosis can only be given if:
  
  • ​Symptomatic and HbA1c > 48 OR fasting plasma glucose > 7
  • Asymptomatic with 2 elevated readings (HbA1c or fasting plasma glucose)

Question 3

DIABETES MELLITUS: Describe the important principles of the dietary and lifestyle interventions for the treatment of diabetes.

Answer 3

Type 1

• Life style changes
  
  • Alcohol intake: Avoid alcohol on an empty stomach, as will be absorbed faster. Have a snack contain carbs before and after drinking alcohol. Extra insulin is not required.
  • Exercise: Insulin dosage and nutritional intake should be adjustment for exercise levels
• Dietary
  
  • Do not advise a low GI diet
  • Structured education programme should include carbohydrate counting training
  • Referral to specialist diabetes team to enable optimal choices about food and appropriate insulin dose changes

Type 2

• Life style changes:
  
  • Aim to be active everyday
  • ​Regular exercise (150 minutes of moderate intensity/week). Reduces CV risk and helps with weight loss
  • Reduce alcohol intake
  • Smoking cessation
• Dietary:
  
  • Low GI diet: Fruit, vegetables, wholegrain, pulses
  • Low-fat dietary products and oily fish
  • High fibre
  • Reduce foods high in saturated and trans fatty acids
  • Discourage the use of foods marketed specifically for diabetes
  • Weight loss target of 5-10% if overweight

Question 4

DIABETES MELLITUS: Describe the methods of evaluating diabetic control

Answer 4

• HbA1c
• Fasting plasma glucose levels
• Signs of end organ damage: Diabetic retinopathy, neuropathy and nephropathy
• Healing e.g. surgical ulcers

Question 5

DIABETES MELLITUS: Classify the different types of oral hypoglycaemic drugs and non-insulin injectable used in Type 2 diabetes and outline their indications and contraindications.

Answer 5

Question 6

DIABETES MELLITUS: In a simulated environment write prescriptions for subcutaneous and intravenous insulin therapy.

Answer 6

Question 7

DIABETES MELLITUS: Describe the essential components of the annual review in diabetes care.

Answer 7

• HbA1c
• Blood pressure
• Monitor CVD risk factors: Lipids, HbA1c
• Monitor for signs of end organ damage: Retinopathy, neuropathy, nephropathy
• Foot check
• BMI

Question 8

DIABETES MELLITUS: List the 2 major hyperglycaemic complications of diabetes

Answer 8

• DKA
• HHS

Question 9

DIABETES MELLITUS: Outline the metabolic pathways that underlie DKA and HHS, understanding the reasons for their development

Answer 9

DKA: Absence of insulin leads to inabilty to absorb dietary glucose. As cells have insufficent glucose to meet metabolic need lipid breakdown occurs, to provide cellular energy. The breakdown of lipids creates keto acids. Creating a metabolic acidosis. Acidosis causes vomiting and further fluid/electrolyte loss. Renal perfusion falls, leading to reduced excretion of H⁺.

HHS: Relative insulin deficiency leads to excessive glucose within the bloodstream. This creates an osmotic gradient, leading to polyuria, ultimately causing dehydration. There is an absence of ketoacids, as there is some residual insulin remaining for glucose resorption into cells.

Reasons for development

• Fundamentally, insulin deficit
• Acute illness
• Omitting insulin therapy
• Undiagnosed DM (typically DKA in T1DM)

Question 10

DIABETES MELLITUS: Describe the typical autonomic and neurological symptoms of hypoglycaemia

Answer 10

Hypoglycaemia is defined as plasma glucose < 3mmol/L.

Autonomic

• Kausmall breathing
• Hyperhidrosis
• Anxiety
• Palpitations
• Tremor

Neurological

• Confusion
• Reduced consciousness
• Seizures

Question 11

DIABETES MELLITUS: Describe the treatment of hypoglycaemia

Answer 11

Classically, in hypoglycaemia pancreatic alpha cells release glucagon to stimulate gluconeogenesis, glycogenolysis and reduce glycogenesis. In T1DM the pancreatic alpha cells become desensitised to hypoglycaemia and hence pts are extremely vulnerable to hypoglycaemia.

Causes: Insulin excess, depletion of hepatic glycogen, pituitary insufficiency (HPA axis), adrenal insufficiency and non-pancreatic malignancies.

Treatment

1. If able to swallow → 10-20g of fast acting carbohydrate (preferentially in liquid form)
2. Recheck blood glucose levels in 10-15 minutes
3. If inadequate response then repeat and recheck
4. If unable to swallow or unconscious → administer IM glucagon (NOTE glucagon is not effective if alcohol has been consumed) or 100ml of 20% glucose if IV access is available - IV glucose can be repeated x3.
5. Following response to glucagon, pt should take on a long acting carbohydrate

IMPORTANT: Following recovery, neer omit insulin in patients with T1DM

Question 12

DIABETES (MICRO AND MACRO VASCULAR COMPLICATIONS): Discuss the microvascular complications of diabetes affecting the eyes, kidneys and nerves and outline their relationship to diabetic control and disease duration.

Answer 12

Ophthalmic: Diabetic retinopathy

Renal: Nephropathy

Neurological: Neuropathy (2º to vascular compromise)

Better diabetic control reduces the risk of microvascular complications and progression of such.

Question 13

DIABETES (MICRO AND MACRO VASCULAR COMPLICATIONS): Describe the features of diabetic sensorimotor neuropathy and associated risks

Answer 13

• Loss of sensation
• Neuropathy - burning pain
• Charcot’s joints
• Glove and stocking distribution
• Cranial nerve lesions can occur, mainly affecting CNs responsible for extraocular muscles

Associated risks

• Diabetic ulcers
• Injury to the peripheries due to loss of sensation

​Pathophysiology: Hyperglycaemia leads to neural hypoxia, oxidative stress and ultimately nerve injury. This leads to loss of peripheral sensation.

Question 14

THYROID DISEASE: Describe the symptoms of hyperthyroidism and the typical examination findings.

Answer 14

Symptoms of hyperthyroidism: Palpitations, sweating, weight loss, appetite increase, amenorrhoea, heat intolerance,

Typical examination findings:

• Exophthalmos (Grave’s)
• Lid lag
• Pretibial myxoedema (Grave’s)
• Goitre
• Tremor

Question 15

THYROID DISEASE: Classify the causes of hyperthyroidism and outline the pathological features of Graves’ disease, toxic adenoma and toxic multinodular goiter

Answer 15

Causes of hyperthyroidism: