Endocrine Flashcards
Approximately how many adults in the UK have type 1 diabetes?
370,000
The incidence of type 1 diabetes peaks between which stages of life?
Early childhood (6 months to 5 years) and then in puberty
Name 5 types of diabetes?
- Type 1
- Type 2
- Gestational
- Monogenic
- Drug/chemical induced
What % chance have you got of developing type 1 diabetes, if your sibling has it?
10%
What are the classic symptoms of type 1 diabetes in children? (4)
- weight loss
- fatigue
- thirst (polydipsia)
- polyuria
What are the classic symptoms/presenting features of type 1 diabetes in adults? (5)
- Rapid weight loss
- Ketosis
- Age of onset younger than 50 years
- BMI < 25kg/m2
- Personal/family history of autoimmune diseases
Which blood test is performed to investigate type 1 diabetes, and what result indicates suspected T1DM?
Random plasma glucose >11mmol/L
How soon should a child be seen if T1DM is suspected?
Same day referral to paediatric diabetes team
If the presentation of T1DM is atypical, what further investigations can be carried out? (2 blood tests?)
- C-peptide
2. Diabetes-specific autoantibody
Which immunisations are particularly important for children with T1DM to have? (2)
- Influenza
2. Pneumococcal infections
How many people in the UK have been diagnosed type 2 diabetes (T2DM)?
3.5 million
What is type 2 diabetes?
A resistance to insulin and a relative insulin deficiency, resulting in persistent hyperglycaemia
What causes type 1 diabetes?
Usually it is a destruction of beta-cells in the pancreatic islets of Langerhans. Most commonly due to autoimmunity.
What are the risk factors for T2DM? (9)
- Obesity and inactivity
- Family history
- Ethnicity - afro/caribbean
- History of gestational diabetes
- Poor dietary habits (low fibre, high GI)
- Drugs: e.g. statins corticosteroids, thiazide diuretic combined with a beta-blocker
- Polycystic ovarian syndrome
- Low birth weight for gestational age
- Metabolic syndrome: raised BP, abnormal blood lipid levels, fatty liver, central obesity
What are the characteristic features/symptoms of T2DM?
Thirst, polyuria, blurred vision recurrent infections, tiredness …however these are not usually severe and may be absent.
What are the complications of poorly managed/undiagnosed T2DM? (the list is endless, but think in terms of microvascular/microvascular/metabolic etc).
- Macrovascular complications - CVD, cerebrovascular disease, peripheral arterial disease
- Microvascular complications - nephropathy, retinopathy and neuropathy
- Metabolic complications - dyslipidaemia and DKA
- Anxiety and depression
- Infections - particularly UTIs and skin infections
- Dementia
Which blood tests are measured to investigate suspected T2DM? and which corresponding levels would indicate it? (3)
- HbA1c >48mmol/mol
- Plasma glucose >11mmol/L
- Fasting plasma glucose >7mmol/L
When should HbA1c not be used to diagnose diabetes? (3)
- In children and young people
- Pregnant women or women <2 months postpartum
- People with end-stage CKD, HIV, pancreatic damage, on corticosteroids
In which gender is hypothyroidism more common?
Females
In the UK what is the most common cause of primary hypothyroidism?
Autoimmune thyroiditis (Hashimoto’s or atrophic)
Worldwide, what is the most common cause of primary hypothyroidism?
Iodine deficiency
What are the causes of primary hypothyroidism? (7)
- Iodine deficiency
- Autoimmune thyroiditis
- Thyroid trauma (e.g. surgery/radiotherapy)
- Drugs: Amiodarone, lithium, interferons, thalidomide, rifampicin, and 15% of people treated with carbimazole/propylthiouracil for hyperthyroidism, will go on to develop hypothyroidism.
- Transient thyroiditis
- Thyroid infiltrative disorders
- Congenital hypothyroidism
What are the causes of secondary hypothyroidism? (2)
- Pituitary dysfunction - tumours (pituitary adenoma), surgery, radiotherapy, trauma, infection, Sheehan’s syndrome, TB, syphilis, sarcoidosis
- Hypothalamic dysfunction - tumours (gliomas), drugs (retinoids/bexarotene), and all above as for pituitary.
What are the risk factors for hypothyroidism? (4)
- Poor intake of dietary iodine (found in fish and dairy products)
- Family history (including other autoimmune diseases too)
- Down’s syndrome
- Amiodarone/Lithium use
There are many other diseases/conditions that can cause hypothyroidism too.
What are the symptoms of hypothyroidism? (8)
- Fatigue
- Cold intolerance
- Weight gain
- Constipation
- Non-specific weakness, myalgia
- Depression, impaired concentration and memory
- Dry skin
- Menstrual irregularities
What is Cushing’s syndrome?
It is a clinical manifestation of pathological hypercortisolism from any cause.
How does Cushing’s syndrome typically present?
Patients often display weight gain with central obesity, facial rounding and plethora, proximal muscle weakness, and thinning of the skin.
What complications can people with Cushing’s syndrome develop? (4)
Metabolic complications including;
- Diabetes
- Dyslipidaemia
- Metabolic bone disease
- Hypertension
What causes Cushing’s syndrome? (3)
- ACTH-secreting pituitary tumours (AKA Cushing’s disease)
- Autonomous adrenal cortisol overproduction
- Ectopic ACTH-secreting tumours
What are the risk factors for developing Cushing’s syndrome? (4)
- Exogenous corticosteroid use
- Pituitary adenoma
- Adrenal adenoma
- Adrenal carcinoma
What symptoms are key diagnostic factors? (at least 4)
- Present of risk factors
- Facial plethora
- Supraclavicular fullness
- Violaceous striae
What are the diagnostic investigations to consider for Cushing’s syndrome? (4)
- Urine pregnancy test
- Serum glucose
- Late-night salivary cortisol
- 1mg overnight dexamethasone suppression test
What is Addison’s disease?
Addison’s disease (primary adrenal insufficiency) is a result of destruction of the adrenal cortex –> this causes reduced production of glucocorticoids (e.g. cortisol), mineralocorticoids (e.g. aldosterone) and adrenal androgens (e.g. dehydroepiandrosterone)
What is the most common cause of Addison’s disease in the developed world?
Autoimmune disease (70-90% of cases)
In lesser developed countries, what is the most common cause of Addison’s disease?
TB
Aside from autoimmune disease and TB, what are the other, rarer causes of Addison’s disease? (5)
- Adrenal metastases
- Adrenal haemorrhage
- Infections e.g. cytomegalovirus and HIV
- Amyloidosis
- Congenital adrenal hyperplasia
Addison’s disease is associated with other autoimmune conditions, what are they? (3)
- Hypothyroidism
- Type 1 diabetes
- Autoimmune polyendocrine syndrome (60% of people with Addison’s)
What are the two types of autoimmune polyendocrine syndrome?
- Polyglandular autoimmune syndrome type 1
2. Polyglandular autoimmune syndrome type 2 (more common) - linked to HLA DR3 and DR4
What is the most common complication of Addison’s disease?
Adrenal crisis
What is an adrenal crisis?
This occurs when a person with Addison’s disease suffers severe physical stress. The adrenal gland cannot supply the extra corticosteroids needed to cope with the stress, and life-threatening symptoms develop. Adrenal crisis may precipitate severe dehydration, hypotension, hypovolaemic shock, altered consciousness, seizures, stroke or cardiac arrest.
Addison’s disease is hard to diagnose, as the symptoms are non-specific and overlap with other conditions, however, when should Addison’s disease be suspected in someone? (6)
In a person with persistent, non-specific symptoms including:
- Fatigue
- Hyperpigmentation (affects 92% of people with Addison’s)
- GI symptoms - weight loss, loss of appetite, cravings for salt, soy sauce or liquorice
- MSK symptoms - muscle weakness, cramps and joint pains
- CV symptoms - postural dizziness due to hypotension
- Headache, low-grade fever, increased thirst/urination
Addison’s disease should be considered in people with what other conditions? (6)
- Hypothyroidism - particularly if symptoms worsen when starting levothyroxine
- Type 1 diabetes
- Pernicious anaemia
- Alopecia
- Coeliac disease
- Hyponatraemia and hyperkalaemia
What are the differential diagnoses for Addison’s disease? (6)
- Gastroenteritis - nausea and vomiting are key features of adrenal crisis
- Depression - chronic fatigue, malaise, anorexia may mimic depression
- Eating disorders
- Type 1 diabetes
- Chronic fatigue syndrome
- Hyperemesis and chloasma of pregnancy
If Addison’s disease or adrenal insufficiency is suspected, what investigation can be requested?
A serum cortisol level and U&Es
- ideally the serum cortisol level should be obtained between 8-9am
What is hyperparathyroidism?
An enlargement of one of the glands resulting in over production of calcium
What is primary hyperparathyroidism associated with?
Primary hyperparathyroidism may be associated with uncommon familial disorders including multiple endocrine neoplasia type 1 and type 2A syndromes, familial hyperparathyroidism-jaw tumour syndrome, and familial isolated hyperparathyroidism
How does parathyroid hormone result in hypercalcaemia?
Excess PTH causes hypercalcaemia by increasing renal calcium reabsorption and mobilizing calcium from bone. It also indirectly increases intestinal calcium absorption, by increasing synthesis of serum 1,25-dihydroxyvitamin D3 (calcitriol, the active form of vitamin D3)
