Endocrine Flashcards
How common is type 1 diabetes?
1 in 20 people in the UK have diabetes
10% of those being type 1
Who does type 1 diabetes affect?
Usually diagnosed before 30 years old
Usually lean individuals
Finland & Sardinia have highest incidence
What causes type 1 diabetes?
Autoimmune destruction of pancreatic beta-cells
Idiopathic in origin but thought to be found in genetically susceptible individuals and is probably triggered by one or more environmental antigens
Auto-antibodies found against insulin, and islet cell antigens predate the onset of clinical disease by several years
There is an association with other organ specific autoimmune disease
What are the risk factors for type 1 diabetes?
Family history
Genetics
Geography (further from equator)
What are the symptoms of type 1 diabetes?
Polydipsia (osmotic diuresis secondary to hyperglycaemia Nocturia Excessive fatigue Weight loss Loss of muscle bulk
Itchiness in genital area (recurrent thrush)
Blurred vision
Slow healing cuts
What are the signs of type 1 diabetes on examination?
Physical examination usually normal
What are the possible differential diagnoses for type 1 diabetes?
UTI
Prostatic hypertrophy
Incontinence
Cancer of the urinary tract
What investigations are necessary to diagnose type 1 diabetes?
Random plasma glucose concentration of >11mmol/L
Fasting plasma glucose concentration of >7.0mmol/L or higher
Urinalysis: microalbuminuria
FBC, serum U&Es, fasting bloods for cholesterol and triglyceride levels
Liver biochemistry
HbA1c levels (using FBC or finger prick) >48mmol/L
What are the treatments for type 1 diabetes?
4 preparations insulins:
Rapid acting - administered shortly before or just after eating. Injected/insulin pump
Short acting - regular/neutral insulin is given before a meal. Injected via syringe/insulin pen
Intermediate acting - isophane insulin
Long acting - no peak of activity allowing constant delivery throughout day (lantus given once a day)
What is type 2 diabetes?
Type 2 diabetes develops when the insulin producing cells in the body are unable to produce enough insulin or when insulin produced does not work properly
Known as insulin resistance
How common is type 2 diabetes?
1 in 20 people have diabetes
Of these, 90% have type 2 diabetes
Who does type 2 diabetes affect?
Usually diagnosed over 30 years
Often overweight
More common in African/Asian decent
What causes type 2 diabetes?
Polygenic disorder Rare forms caused by mutations in insulin receptors Environmental factors: - central obesity - trigger genetically susceptible
What are the risk factors for type 2 diabetes?
>40 years old Family history Overweight/obesity South Asian/Chinese/Afro-Caribbean/Black African ethnicities Previous cardiovascular disease Female with polycystic ovaries Impaired glucose tolerance
What are the symptoms of type 2 diabetes?
Polydipsia Nocturia Excessive fatigue Weightloss Itchiness in genital area Blurred vision
What are the signs of type 2 diabetes on examination?
Physical examination usually normal in early stages Pts usually overweight Chronic uncontrolled: - hypertension - retinal haemorrhages - absent pedal pulses - loss of deep tendon reflexes in ankle -
What are the possible differential diagnoses of type 2 diabetes?
Metabolic syndrome UTI Prostatic hypertrophy Incontinence Cancer of urinary tract
What investigations are required to diagnose type 2 diabetes?
HbA1c levels measured using FBC or using finger-prick method
- >48mmol/L = type 2 diabetes
Random non fasting plasma glucose concentration >11.1mmol/L
What are the treatment for type 2 diabetes?
Lifestyle changes: diet, weight, level of physical activity
Medication:
- Metformin = first line in type 2 diabetes, reduced CV risk
- sulphonylureas (gliclazide) = promote insulin secretion, prescribed if pt can’t take Metformin
How common is hypothyroidism?
15 in every 1000 women in UK
1 in every 1000 men in UK
Who does hypothyroidism affect?
More common in women
Usually 40-50 (menopausal years)
What are the causes of hypothyroidism?
Autoimmune disease: most common Hashimotos
- cytotoxic T-cells and autoantibodies directed against thyroglobulin and thyroid peroxidase
- first stimulate the thyroid causing enlargement, and then destroy the thyroid follicles causing atrophy of thyroid
Pituitary or hypothalamic failure causing secondary hypothyroidism
Genetic dysfunction: thyroid may be dysfunctional at birth or is predisposed later in life
Chronic iodine deficiency (iodine required to make thyroid hormones)
Treatment for hyperthyroidism
What are the risk factors for hypothyroidism?
Gender (female) Age >60yrs Environmental (iodine deficiency) Autoimmune disease Family History Treatment with radioactive iodine Radiation to neck/upper chest
What are the symptoms of hypothyroidism?
Depends on severity
Fatigue Increased sensitivity to cold Constipation Dry/scaly skin Unexplained weight gain Muscle weakness Elevated blood cholesterol level Pain, stiffness, swelling of joints Heavier or irregular menstrual periods Hair thinning Depression
What are the signs of hypothyroidism on examination?
Slow speech, dull facial expression Psychosis Low BP, bradycardia Dry skin, coarse brittle, straw-like hair, loss of hair Overweight Jaundice, pallor Goitre Pericardial effusion, oedema (non pitting) Hyporeflexia
What are the possible differential diagnoses of hypothyroidism?
Anaemia Autoimmune thyroid disease and pregnancy Thyroid lymphoma Chronic fatigue syndrome Depression Menopause
What investigations are necessary to diagnose hypothyroidism?
Thyroid function tests: looking at TSH and thyroxine (T4) levels
- ⬆️ TSH and ⬇️ T4 = primary hypothyroidism
- primary hypothyroidism only disease where sustained raised TSH
Assays for anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-Tg) antibodies helpful in determining aetiology
What are the treatments of hypothyroidism?
Thyroxine replacement therapy
Levothyroxine (T4)
- main treatment
Liothyronine (T3)
- is active hormone and acts quicker than T4 but shorter duration so BD
How common is hyperthyroidism?
8 in 100 women develop
1 in 100 men develop
Who does hyperthyroidism affect?
More common in women
More commonly begins 20-40 years
More common in white people
What are the causes of hyperthyroidism?
Graves’ disease:
- autoimmune disease
- most common cause of an overactive thyroid (80%)
- most common in females
- anti-thyroid stimulating hormone receptor antibodies (IgG) stimulate thyrocytes to secrete thyroid hormones
Toxic multi nodular goitre
Toxic adenoma
- responsible for 5% of hyperthyroidism cases
Thyroiditis
Over medication of thyroxine
Pituitary problems
What are the risk factors for hyperthyroidism?
Gender (female) Family history Smoking High iodine intake Thyroid trauma Child birth Stress Genetics
What are the symptoms of hyperthyroidism?
Weight loss despite increased appetite Restlessness, irritability Breathlessness, palpitations Heat intolerance, increased thirst, sweating Itching, thinning hair Malaise, vomiting, diarrhoea Infrequent, light menstruation - oligomenorrhoea Eye complaints Stiffness, muscle weakness, tremor Oncholysis
What are the signs of hyperthyroidism on examination?
Tremor Hyperkinesis Psychosis Proximal myopathy, muscle wasting, pretibial myxoedema Oncholysis, thyroid acropatchy Palmar erthema Tachycardia, AF Warm, vasodilated peripheries Systolic hypertension Exophthalmos, lid lag, stare Goitre, bruit
What are the possible differential diagnoses of hyperthyroidism?
Graves’ disease
Goitre
Thyrotoxicosis
What investigations are necessary to diagnose hyperthyroidism?
Thyroid function test: looking at levels of thyroid stimulating hormone (TSH) and thyroxine (T4)
- serum TSH suppressed
- serum free T3 and T4 elevated
Thyroglobulin antibodies
Thyroid ultrasound
What are the treatments of hyperthyroidism?
Anti thyroid drugs
- Carbimazole - blocks thyroid hormone synthesis and have immunosuppressive effects which affects Graves’ disease process
- beta blockers - as most symptoms Re mediated via sympathetic nervous system
Radioactive iodine treatment
- accumulates in thyroid gland and causes local irradiation damage
Surgery
- thyroidectomy
How common is goitre?
Affects 12% people worldwide
Who does goitre affect?
More common in women
More common in >40s
What are the causes of goitre?
Diffuse: entire thyroid gland enlarged and smooth to touch
- Physiological; puberty, pregnancy
- Autoimmune; graves, Hashimotos
- Acute viral thyroiditis
- Iodine deficiency
Nodular: solid or fluid filled nodules present, lumpy to touch, multiple or single nodules
- multi nodular
- solitary nodule
- fibrotic
- cysts
Tumours:
- adenoma
- carcinoma
- lymphoma
What are the risk factors for goitre?
Gender (female) Age (⬆️ with age) Family history Iodine deficient diet Pregnancy and menopause Medication Exposure to radiation
What are the symptoms of goitre?
Usually noticed as cosmetic defect Discomfort/pain in neck Difficulty breathing/swallowing (tracheal compression Hoarseness/change in voice Symptoms for hypo&hyperthyroidism
What are the signs of goitre on examination?
Bruit
Lymphadenopathy
What are the possible differential diagnoses of goitre?
Oesophageal cancer
Tracheal/bronchial cancer
What investigations are necessary to diagnose goitre?
Blood tests:
- thyroid function and thyroid antibodies
Imaging
- high resolution thyroid ultrasound
FNA
- cytology necessary to assess for malignancy
Thyroid scan
What are the treatments for goitre and thyroid nodule?
Watch and wait
Anti thyroid medication/radioactive iodine
Levothyroxine
Surgical intervention
What is the goitre grading system?
0 = not palpable or visible even when neck extended 1 = palpable 1A = detected on palpation 1B = palpable and visible when neck extended 2 = visible when neck in normal position 3 = large goitre visible from distance
Simple = non toxic Toxic = hyperthyroid
How common is thyroid nodule?
1 in 12-15 young women
1 in 40 young men
Who does thyroid nodule affect?
More common in women Increasing incidence with age 50% 50 yr olds 60% 60 yr olds 70% 70 yr olds
What are the causes of thyroid nodules?
Iodine deficiency Hypertrophy of thyroid tissue Thyroid cyst Thyroiditis Multi- nodular goitre thyroid cancer
What are e risk factors for thyroid nodules?
Gende (female) ⬆️ age Radiation to neck/upper chest Pre-existing thyroid condition Family history
What are the symptoms of thyroid nodules?
Usually Asymptomatic Usually noticed as cosmetic defect Discomfort/pain in neck Difficulty breathing/swallowing Hoarseness/voice changes Symptoms of hypo/hyper thyroid
What are the signs of thyroid nodules on examination?
Moveable (less likely to be malignant)
Fixed nodule - malignancy
Lymphadenopathy
What is the differential diagnosis for thyroid nodule?
Goitre
What investigations are necessary to diagnose thyroid nodules?
Blood tests- serum TSH and free T4
Immunoassays: antibodies titres to thyroperoxidase or thyroglobulin
FNA
Thyroid ultrasound
- detects poorly palpable nodules
- determine size/number of nodules, solid/cystic
- assist in FNA
Radionuclide scanning
How common is Cushing’s syndrome?
Very rare
1 in 50,000
Who does Cushing’s syndrome affect?
Adults 20-50 years
Women 3x more likely
What are the causes of Cushing’s syndrome?
Adrenocorticotrophic hormone (ACTH) dependent causes:
- pituitary dependent (Cushing’s disease): primary hyper- secretion of ACTH
- ectopic ACTH- producing tumours
Non- ACTH dependent causes
- adrenal adenomas
- adrenal carcinomas
- glucocorticoid administration
Other
- alcohol induced pseudo-Cushing’s syndrome
What are the risk factors for Cushing’s syndrome?
Obesity
Type 2 diabetes
Poorly controlled blood glucose
Hypertension
What are the symptoms of Cushing’s syndrome?
Weight gain Change of appearance Depression Insomnia Amenorrhoea/oligomenorrhoea Thin skin/easy bruising Muscular weakness Back pain
What are e symptoms of Cushing’s syndrome on examination?
Moon face Plethora Depression/psychosis Thin skin/bruising, skin infections Hypertension Osteoporosis, kyphosis, pathological fractures, rib fractures Buffalo hump Central obesity, striae, Proximal myopathy, proximal muscle wasting
What are the possible differential diagnoses of Cushing’s syndrome?
Cushing’s disease
Hypothyroidism
Hypertension
What investigations are necessary to diagnose Cushing’s syndrome?
Confirm raised cortisol
Establishing cause of Cushing’s syndrome:
- adrenal CT/MRI will detect adrenal adenomas and carcinomas
- pituitary MRI and CT will detect some but not all pituitary adenomas
Corticotrophin- releasing hormone test
What is the difference between Cushing’s disease and Cushing’s syndrome?
Cushing’s disease is when the ACTH comes from the pituitary gland
Cushing’s syndrome is where there is an adrenal tumour producing too much cortisol, or too much ACTH is made which causes the adrenal glands to make cortisol
What are the treatments for Cushing’s syndrome?
Surgical removal for most pituitary tumour indicated
Drugs inhibiting cortisol synthesis
External beam irradiation to pituitary
Iatrogenic Cushing’s syndrome
What is parathyroid adenoma?
Benign tumour of parathyroid gland and last common cause of hyperparathyroidism
Leads to hypercalcaemia
What other aetiology of parathyroid adenoma?
Genetic
Idiopathic
Secondary to excess PTSH
What are the risk factors for parathyroid adenoma?
Age (>60yrs)
Irradiation
What are the symptoms of parathyroid adenoma?
Often Asymptomatic Confusion Constipation Lethargy Muscle pain Nausea
What is the aetiology of primary hyperparathyroidism?
Single parathyroid adenoma
- most common cause
- benign
- increased parathyroid hormone
Hyperplasia of multiple parathyroid glands
- benign enlargement
- increased parathyroid hormone
Parathyroid carcinoma
- very rare cause
What is the aetiology of secondary hyperparathyroidism?
Kidney disease
- hypocalcaemia leading to over stimulation
Vitamin D deficiency
- hypocalcaemia
Intestinal malabsorption
- hypocalcaemia
What are the symptoms of hyperparathyroidism?
Tiredness Muscle weakness Nausea/vomiting Constipation Abdo pain Polydipsia Polyuria Depression
What are the complications of hyperparathyroidism?
Kidney stones Corneal calcification Pancreatitis Peptic ulceration Renal damage
What is Addison’s disease?
Primary adrenal insufficiency (hypoadrenalism)
Rare condition in which there is destruction of entire adrenal cortex therefore not enough cortisol or aldosterone is produced
What is the aetiology of Addison’s disease?
90+% of cases are auto antibody destruction
Others: surgical removal, TB, haemorrhage
What are the symptoms of Addison’s disease?
Lethargy Depression Anorexia Weight loss Postural hypotension - salt and water loss Hyper pigmentation
What is addisonian crisis?
Vomiting Abdo pains Profound weakness Hypoglycaemia Hypovolaemic shock
What investigations are necessary to diagnose Addison’s disease?
Single cortisol measurements Short ACTH stimulation test Plasma ACTH level Long ACTH stimulation test Adrenal antibodies testing
What is Type 1 diabetes?
It is an autoimmune disease that causes the insulin producing beta cells in the pancreas to be destroyed, preventing the body from being able to produce enough insulin to adequately regulate blood glucose levels
