Endocrinology Flashcards
What is the aetiology of T1DM?
Insulin deficiency from B cell destruction of insulin secreting pancreatic beta cells, associated with HLA DR3
What is the pathophysiology involved in T1DM?
There is inadequate insulin secretion relative to the needs of the body leading to hyperglycaemia and deranged metabolism
What are the symptoms of T1DM?
Polyuria, weight loss, fatigue, thirst, visual blurring, genital thrush, lethargy
What are the signs of T1DM?
Ketonuria, recurrent infections, drowsiness, coma, normal body weight
What tests are used to diagnose T1DM?
Abnormal plasma glucose (random >/= 11.1 mmol/L or fasting >/= 7 mmol/L) in the presence of symptoms
In asymptomatic people with an abnormal random glucose 2x fasting plasma glucose (ranges still the same)
Oral glucose tolerance test
What is the treatment for T1DM?
Diabetes education and lifestyle advice
Insulin
What are the possible complications of T1DM?
Vascular disease, neuropathy, retinopathy, cataracts, glaucoma, ketoacidosis, foot ulcers, nephropathy
What is the aetiology of T2DM?
There is impaired insulin secretion and insulin resistance
What are the risk factors for T2DM?
Obesity, lack of exercise, calorie and alcohol excess, PCOS
What is the pathophysiology involved in T2DM?
There is diminished effectiveness of endogenous insulin leading to hyperglycaemia and deranged metabolism
What ethnicities have an increased risk of T2DM?
Asian, African, Polynesian
What are the symptoms of T2DM?
May be asymptomatic or present with complications e.g. MI
Polyuria, thirst, lethargy, boils
What are the signs of T2DM?
There are no obvious physical signs - the patient is usually overweight
What tests are used to diagnose T2DM?
HbA1c >48 (6.5%)
Fasting glucose >/= 7 mmol/L (>6.5 - impaired glucose tolerance)
Oral GTT @ 2 hours >/= 7.8 mmol/L (>6.1 - impaired glucose tolerance)
What is the treatment for T2DM?
Metformin (increases insulin sensitivity and helps weight)
If HbA1c >/= 53 16 weeks later add: sulfonylurea e.g. glicazide
If HbA1c >/= 57 at 6 months, consider: insulin, glitazone or sulfonylurea receptor binders
Education and lifestyle advice e.g. reduce weight, start a statin, control BP
What are the complications of T2DM?
Hyperosmolar hyperglycaemic state - severe hyperglycaemia and marked serum hyperosmolarity
Chronic: vascular disease, nephropathy, retinopathy, cataracts, glaucoma, ketoacidosis, foot ulcers, neuropathy
What is the aetiology of DKA?
Infection, discontinuation of insulin, inadequate insulin, cardiovascular disease, drugs e.g. steroids, thiazides
What is the pathophysiology involved in DKA?
There is uncontrolled hyperglycaemia and a catabolic state leading to ketones being produced as the body requires glucose in cells causing acidosis
What are the symptoms of DKA?
Polyuria, polydipsia, vomiting, weakness, lethargy, altered mental state including coma
What are the signs of DKA?
Dehydration, tachycardia and weak pulse, hypotension, ketotic breath - “pear drops”, deep breathing - Kussmaul respiration
What tests are used to diagnose DKA?
ECG, CXR, MSU - dipstick
Bloods - capillary and plasma glucose, ketones U&Es, HCO3-, amylase, osmolality, FBC, culture, ABG/VBG - ketonaemia (++), hyperglycaemia (>11), venous ph (<7.3) HCO3- (<16)
What is the treatment of DKA?
ABCDE
Fluid replacement - 500ml of 0.9% NaCl bolus
Insulin 0.1u/kg/hr of Actrapid IV
When glucose <14 mmol/L start 10% glucose 125ml/H
Monitor U&Es
Find and treat the cause of DKA e.g. infection
What is the aim of DKA treatment?
Decrease ketones by 0.5 mmol/L/hour
OR
Rise in venous bicarb of 3 mmol/L/hour
What is the aetiology of hypothyroidism?
Primary (low T4): primary atrophic hypothyroidism, Hashimoto’s thyroiditis (anti-TSHR, anti-Tg, anti-TPO antibodies & goitre), iodine deficiency, post-thyroidectomy/radioiodine/antithyroid drugs, drugs e.g. lithium
Secondary (low TSH): hypopituitarism
What is the pathophysiology involved in hypothyroidism?
There is insufficient secretion of thyroid hormones and can be due to various abnormalities
What is the epidemiology of hypothyroidism?
Women>men
What are the symptoms of hypothyroidism?
Tiredness, weight gain, lethargy, low mood, cold intolerance, goitre, constipation, hoarse voice, myalgia, decreased memory/cognition, menorrhagia
What are the signs of hypothyroidism?
BRADYCARDIC! Bradycardic Reflexes relax slowly Ataxia (cerebellar) Dry thin hair/skin Yawning/drowsy/coma Cold hands ± low temperature Ascites Round puffy face Defeated demeanour Immobile ± ileus CCF
What tests are used to diagnose hypothyroidism?
Bloods: FBC (macrocytosis), TFTs (high TSH, low T4), lipids/cholesterol (raised), antibodies (anti-TPO, anti-thyroglobulin
What is the treatment of hypothyroidism?
Levothyroxine (T4) - review at 12 weeks, adjust 6 weekly
Give smaller doses to elderly patients as there’s a risk of angina/MI
What is the aetiology of hyperthyroidism?
Graves’ disease (IgG bind to and stimulate the TSH receptors
Toxic mulitnodular goitre, toxic adenoma, ectopic thyroid tissue, exogenous (iodine excess), DeQuervain’s thyroiditis (post-viral)
What is the pathophysiology of hyperthyroidism?
Excess thyroid hormone is usually due to gland hyperfunction leading to thyrotoxicosis
What is the epidemiology of hyperthyroidism?
Female>male
What are the symptoms of hyperthyroidism?
Palpitations, diarrhoea, heat intolerance, low weight, increased appetite, oligomennorrhoea ± infertility
What are the signs of hyperthyroidism?
Palmar erythema, warm moist skin, fine tremor, tachycardia, SBT, AF, thin hair, lid lag/retraction, goitre, nodules, bruit
What tests are used to diagnose hyperthyroidism?
Bloods: FBC (normocytic anaemia), TFTs (low TSH, high T3, T4) LFTs (increased), ESR (increased), Calcium (increased), thyroid autoantibodies, visual fields, acuity and eye movements
What is the treatment for hyperthyroidism?
Drugs: beta-blockers or carbimazole
Radioiodine or thyroidectomy
What is thyroid eye disease?
Retro-orbital inflammation and lymphocyte infiltration results in swelling of the orbit
What is the management for thyroid eye disease?
Conservative e.g. stop smoking, sunglasses
IV methylprednisolone
Surgical decompression or eyelid surgery
What are some risk factors for thyroid cancer?
Exposure to ionising radiation, history of goitre, thyroid nodules or thyroiditis, female gender, genetics
What are the different types of thyroid cancer?
Papillary (60%) Follicular (<25%) Medullary (5%) Lymphoma (5%) Anaplastic
What are the symptoms of thyroid cancer?
Thyroid nodule usually non-tender
What are the signs of thyroid cancer?
Thyroid nodule - hard and fixed nodules are more suggestive of malignancy, usually non-tender to palpation
Firm cervical masses - ?regional lymph node mets
Vocal cord paralysis - involvement of the recurrent laryngeal nerve
What tests are used to diagnose thyroid cancer?
TFTs - normal in most patients
USS, fine needle aspiration cytology, radionuclide imaging
CT/MRI scans
What is the treatment for thyroid cancer?
Surgery: total or subtotal thyroidectomy
Radiotherapy or radioiodine ablation therapy
Chemotherapy: sorafenib (multi kinase inhibitor)
What is the aetiology of Cushing’s syndrome?
Pituitary adenoma (then called Cushing’s disease), exogenous glucocorticoids, adrenal adenoma, adrenal carcinoma, ectopic ACTH production (e.g. small cell lung cancer
What is the pathophysiology of Cushing’s syndrome?
There is chronic glucocorticoid excess, loss of the normal feedback mechanisms and loss of circadian rhythm of cortisol secretion
What is the epidemiology of Cushing’s syndrome?
Higher incidence in patients with DM, HTN, obesity
What are the symptoms of Cushing’s syndrome?
Increased weight, depression, lethargy, irritability, psychosis, acne, proximal weakness, gonadal dysfunction (irregular menses, ED, hirsutism)
What are the signs of Cushing’s syndrome?
Central obesity, buffalo neck hump, moon face, purple striae on the abdomen, supraclavicular fat distribution, skin and muscle atrophy, bruises, osteoporosis, hypertension, hyperglycaemia, infection - prone/poor healing
What tests are used to diagnose Cushing’s syndrome?
Bloods (increased plasma cortisol)
Overnight dexamethasone suppression test (no suppression in Cushing’s)
48 hour dexamethasone suppression test (no suppression in Cushing’s)
Circadian rhythm plasma cortisol levels
Imaging - adrenal CT or MRI, pituitary MRI
What is the treatment for Cushing’s syndrome?
Iatrogenic - stop steroids
Cushing’s disease - trans-sphenoidal surgery or bilateral adrenalectomy (causes Nelson’s syndrome)
Adrenal adenoma - adrenalectomy
Adrenal carcinoma - adrenalectomy, radiotherapy and adrenolytics (mitotane)
Ectopic ACTH - surgery if localised
What is the aetiology of Addison’s disease?
Autoimmunity, TB, surgical removal of the adrenal glands, haemorrhage or infarction, infiltration, Schilder’s disease