Endocrinology Flashcards
When the blood glucose levels decrease, what cells detect the change? What do they release as a result of this change?
Alpha cells in the Islets of Langerhans.
Glucagon
When the blood glucose levels increase, what cells detect the change? What do they release as a result of this change?
Beta cells in the Islets of Langerhans.
Insulin
Insulin release is stimulated by what type of neurons?
Parasympathetic
Briefly describe what Type 1 diabetes is?
An autoimmune disease causing destruction of beta cells leading to insulin deficiency. Caused by genetic and environmental triggers
In type 1 diabetes, insulin isn’t secreted. What is the chain of effect on the body?
Continued breakdown of liver glycogen to blood glucose. Unrestrained lipolysis and muscle breakdown. Glucose is not up taken.
What are the common symptoms and causes of a presenting Type 1 diabetic?
Polyuria- excessive passing of urine Polydipsia- extreme thirst Weight loss- body in catabolic state Glycosuria- excess glucose in urine Ketonuria- ketones present in urine
Explain the pathophysiology of ketone formation in uncontrolled type 1 diabetes
Lack of insulin leads to increased glucagon levels
Leads to an increased catabolic state. Fat breakdown produces more FFA and glycerol. FFA provide energy oxidised into ketone bodies –> ketoacidosis
What is the main treatment for type 1 diabetes?
Insulin therapy
What is the name of the type of T1 diabetes presenting later in life with a slower insulin dependence?
Latent autoimmune diabetes of adults (LADA)
Name some non-modifiable risk factors of type 2 diabetes
Older age
Men
Asian ethnicity
Briefly describe the pathophysiology of type 2 diabetes
Either impaired insulin secretion or insulin resistance –>
Impaired glucose tolerance- higher than normal levels glucose –> progressive hyperglycaemia and high FFA –> reduced muscle and fat uptake after eating + reduced lipolysis and high FFA –> glycosuria (high sugar in urine).
Still v low levels of insulin protects from muscle catabolism so v rarely get ketonuria
Name the modifiable risk factors of type 2 diabetes mellitus
Obesity Calorie excess/ bad diet Lack of exercise Smoking Alcohol consumption
What are some indications of pre-diabetes?
Impaired glucose tolerance- high blood glucose levels
Impaired fasting glucose
What is a good test used to look at longer term blood glucose?
HbA1c- glycated haemoglobin
A type of haemoglobin with glucose attached. Gives long term view of blood glucose levels.
For the HbA1c test- what level is classed as normal, pre-diabetic and diabetic? (units value and %)
Normal: <39 / <5.7%
Pre-diabetes: 39-46 / 6.4%
Diabetes: >46 / >6.4%
What are three commonly used drug treatments for T2 diabetes and how do they work?
Metformin (oral)- increase insulin sensitivity. SE: diarrhoea, nausea.
Sulfonylurea (oral)- increase insulin secretion. SE: hypoglycaemia, weight gain
Insulin (SC)
What is ketoacidosis and when can it occur?
Formation of ketones. Lack of insulin/insensitive –> break down of muscle releasing FFA which are metabolised for energy making ketones.
Can occur in T1 diabetes and starvation.
How would ketoacidosis be diagnosed?
Acidaemia- blood pH >7.3
Hyperglycaemia
Ketonemia- ketones in urine
What are some potential complications of ketoacidosis?
Cerebral oedema, aspiration pneumonia, hypokalaemia, hypomagnesaemia, hypophosphatemia,
thromboembolism.
What would pre-dispose somebody to have a hyperosmolar hyperglycaemic non ketotic coma
Type 2 diabetic
Dehydrated with high glucose. No acidosis
Name some common complications of type 2 diabetes
Infections at insulin injection sites Vascular disease: MI, stroke, hypertension Nephropathy Diabetic feet Ulcerations Cataracts Diabetic retinopathy
What is the commonest presentation of thyroid disease?
Goitre- a swelling of the thyroid gland causing a lump on the front of the neck
What is the function of thyroid hormone?
Develops the NS Metabolic rate Breathing and HR F or F response Regulation of vital body functions: e.g body weight, cholesterol levels, body temp etc
Briefly describe what Graves disease is
An autoimmune disease of the thyroid.
Most common cause of hyperthyroidism by overproducing thyroid hormones. 2/3rds of hyperthyroid cases due to it
What are some signs and symptoms of Graves disease?
Irritability Weight loss Muscle weakness Sleeping problems Tachycardia Heat intolerance Diarrhoea Graves opthalmothapy- bulging eyes
What is the treatment for Graves disease?
Anti-thyroid drugs
Thyroidectomy- removal of all or part of thyroid
Methyl prednisolone
What is thyrotoxicosis?
An excess of thyroid hormone in the body from ANY CAUSE
Therefore also low level of TSH (thyroid stimulating hormone)
Define hyperthyroidism
An overactive thyroid gland leading to an excess of thyroid hormone levels
What can cause hyperthyroidism?
Graves disease
Adenoma- benign tumour of glandular tissue causing increased release
Congenital
Drug induced: Iodine, amiodarone (treats arrhythmias but can prevent T3 to T4 conversion, lithium
What are some common symptoms of hyperthyroidism?
Weight loss Goitre Tachycardia Palpitations Hyperphagia- increased appetite Anxiety Tremor Irritable Heat intolerance and sweating- in shorts in winter etc etc
What are the common signs (not symptoms) of hyperthyroidism?
Graves: goitre, eye disease
Adenoma- solitary nodules