Endocrinology Flashcards
What are the diagnostic criteria for T2DM based on plasma glucose in a symptomatic patient?
- Fasting glucose greater than or equal to 7.0 mmol/l
- Random glucose greater than or equal to 11.1 mmol/l (or after 75g oral glucose tolerance test)
What are the diagnostic criteria for T2DM based on plasma glucose in an asymptomatic patient?
- Fasting glucose greater than or equal to 7.0 mmol/l
- Random glucose greater than or equal to 11.1 mmol/l (or after 75g oral glucose tolerance test)
- Must be demonstrated on two separate occasions
What are the diagnostic criteria for T2DM based on HBA1c?
A HbA1c of greater than or equal to 48 mmol/mol (6.5%) is diagnostic of diabetes mellitus
What are the minimum recommended times of day for a patient with T1DM to routinely self-monitor their capillary blood glucose levels?
At least 4 times a day, including before each meal and before bed
What conditions are associated with MEN-1?
Hyperparathyroidism (+ hypercalcaemia), pituitary disease and pancreatic disease such as insulinomas or gastrinomas
What conditions are assocaited with MEN-2a?
- Medullary thyroid cancer (70%)
- Parathyroid (60%)
- Phaeochromocytoma
What conditions are assocaited with MEN-2b?
- Medullary thyroid cancer
- Phaeochromocytoma
- Marfanoid body habitus
- Neuromas
What advice should be given to patients on metformin who are participating in Ramadan?
During Ramadan, one-third of the normal metformin dose should be taken before sunrise and two-thirds should be taken after sunset
T2DM. Metformin not tolerated. What next?
Next option should be either a DPP4 inhibitor, SGLT2 inhibitor, sulfonylurea, or thiazolidinedione
Which type of oral steroid has the least amount of mineralocorticoid activity?
Dexamethasone
What blood results are associated with hypercalcaemia secondary to malignancy?
PTH is low, although PTHrP may be raised
What is the preferred investigation for T1DM?
Random plasma glucose (HbA1c not recommended)
What anti-diabetic drug is contraindicated with a history of bladder cancer?
Pioglitazone
What is the best test to diagnose Addison’s disease?
The short synacthen test
List the drug causes of raised prolactin
- Metoclopramide, domperidone
- Phenothiazines
- Haloperidol
- Very rare: SSRIs, opioids
In patients with T2DM, what drug should be introduced if they develop CVD, a high risk of CVD or chronic heart failure?
SGLT-2 inhibitor (e.g. dapagloflozin)
Management of patients with type I diabetes and a BMI > 25
Should be considered for metformin in addition to insulin
What water deprivation test results are associated with primary polydipsia?
- Urine osmolality after fluid deprivation: high
- Urine osmolality after desmopressin: high
Patient commenced on vitamin D. Blood tests show mild hypercalcaemia, low phosphate and raised PTH.
What is the most likely diagnosis?
Primary hyperparathyroidism (unmasked by vitamin D replacement)
What dexamethasone suppression test results are associated with Cushing’s?
Cortisol is not suppressed by low-dose dexamethasone but is suppressed by high-dose dexamethasone
TD2M already on 2 drugs - if HbA1c > 58 mmol/mol then what should be offered?
- Metformin + DPP-4 inhibitor + sulfonylurea
- Metformin + pioglitazone + sulfonylurea
- Metformin + (pioglitazone or sulfonylurea or DPP-4 inhibitor) + SGLT-2 if certain NICE criteria are met
- Insulin-based treatment
What is the commonest cause of Addison’s disease in the U.K?
Autoimmunity
What visual field defect is associated with a prolactinoma?
Bi-temporal superior quadrantanopia
What brain MRI results would indicate a prolactinoma?
An abnormally enlarged pituitary gland that is sitting within the sella turcica
What blood results are associated with tertiary hyperparathyroidism?
- Extremely high serum PTH
- Moderately raised serum calcium
- Low-normal phosphate
What blood results are associated with Addison’s?
Hyponatraemia, hyperkalamia, hypoglycaemia
What is the most common type of thyroid cancer?
Papillary
What can be used as a tumour marker in papillary and follicular thyroid cancer?
Thyroglobulin
What findings on light microscopy are associated with papillary thyroid carcioma?
Orphan Annie eyes
What can be used as a tumour marker in medullary thyroid carcinoma?
Calcitonin
What investigation can be used to distinguish between unilateral adenoma and bilateral hyperplasia in primary hyperaldosteronism?
Adrenal venous sampling
What is the confirmatory test for Addison’s disease?
Synthactin (ACTH) stimulation test
How do thyroid disorders affect periods?
Hyperthyroidism is associated with oligomennorhoea, or amennorhoea, whereas hypothyroidism is associated with menorrhagia
What advise should be given to patients on long-term steroids during intercurrent illness?
Double the dose
What is the first line management for control of blood pressure while awaiting definitive management of pheochromocytoma?
- Alpha (e.g. phenoxybenzamine) and beta blockade (e.g. propranolol, labetalol)
- Alpha blocker should be given BEFORE beta blocker
What hormone test results are associated with Klinefelter’s syndrome?
Hypergonadotrophic hypogonadism - FSH and LH concentrations are elevated and serum testosterone concentrations are low
Describe the presentation of Klinefelter’s syndrome
- Often taller than average
- Lack of secondary sexual characteristics
- Small, firm testes
- Infertile
- Gynaecomastia - increased incidence of breast cancer
What is the first line tretment for a hypoglycaemic conscious patient who is able to swallow?
- Fast-acting carbohydrate by mouth i.e.. glucose liquids, tablets or gels
- e.g. 30g glucose gel
Wha drugs can reduce the absorption of levothyroxine?
Iron/calcium carbonate - should be given 4 hours apart
What complications are associated with subclinical hyperthyroidism?
Atrial fibrillation, osteoporosis and possibly dementia
What is the key parameter to monitor in patients with hyperosmolar hyperglycaemic state?
Serum osmolality
In TD2M, if a triple combination of drugs has failed to reduce HbA1c you should switch one of the drugs for what type of drug?
GLP-1 mimetic e.g. liraglutide
What is the first line investigation for primary hyperaldosteronism?
Plasma aldosterone/renin ratio
A 27-year-old female develops eye pain and reduced visual acuity following the initiation of treatment for her recently diagnosed Grave’s disease.
Which one of the following treatments is likely to have been started?
Radioiodine treatment
What are the target blood pressure readings for a patient with T2DM?
The same as for non-T2DM:
- Clinic reading: < 140 / 90
- ABPM / HBPM: < 135 / 85
Describe the presentation of Addison’s disease
- Confusion
- Hyperpigmentation
- Low blood pressure
What blood test results are associated with primary hyperparathyroidism?
- Hypercalcaemia and increased PTH
- Normal urea and electrolytes
What are the sick day rules for T1DM?
- If a patient is on insulin, they must not stop it due to the risk of diabetic ketoacidosis
- Check blood glucose more frequently, for example, every 1-2 hours including through the night
- Consider checking blood or urine ketone levels regularly
- Maintain normal meal pattern if possible
- Aim to drink at least 3 L of fluid (5 pints) a day to prevent dehydration
What blood test and thyroid scintigraphy scan results are associated with De Quervain’s thyroiditis?
Initial hyperthyroidism (raised TSH, T3 and T4), eventually resulting in hypothyroidism
- Globally reduced uptake of iodine-131
What autoantibodies are associated Graves disease?
TSH receptor stimulating autoantibodies
A 34-year-old woman was found to have persistently raised thyroid stimulating hormone (TSH) and normal thyroxine (T4) levels on routine blood tests.
What is the most appropriate next investigation test for her?
Thyroid peroxidase antibodies
Check thyroid peroxidase antibodies in patients who have subclinical hypothyroidism as this can indicate patients who are more likely to progress to overt hypothyroidism
Hypoglycaemia with impaired GCS. IV access is present.
What is the most appropriate next step in management?
IV glucose
What type of drug is gliclazide?
Sulfonylurea
What are the important adverse effects of sulfonylreas?
- Hypoglycaemic episodes
- Weight gain
- Hyponatramia
- Hepatoxicity (typically cholestatic)
How do sulfonylureas cause weight gain?
They directly increase the amount of insulin secreted by the pancreas via binding to ATP-K+ channels on the beta cells, which in turn stimulates cells to store glucose in the form of fat
What drug should be used in new cases of new Graves’ disease to help control symptoms?
Propranolol
Describe the presentation of primary hyperparathyroidism
Depression, nausea, constipation, bone pain
The presence of an elevated prolactin level along with secondary hypothyroidism and hypogonadism is indicative of?
Non-functioning pituitary adenoma
Describe the presentation of gliclazide overdose?
Hyperinsulinemia and high C-peptide levels
Name a drug which can cause hypercalcaemia
Thiazides
DKA: ketonaemia and acidosis have not been resolved within 24 hours
What is the next step in management?
Patient should be reviewed by a senior endocrinologist
Medullary thyroid cancer is associated with what oncogene?
RET oncogene
Patient with Addison’s has persistent vomiting. What advise should be given?
IM hydrocortisone
A 34-year-old female presents with a thyroid nodule. She has a family history of thyroid disease and both her sisters have undergone total thyroidectomies. Her past medical history includes hypertension which has been difficult to manage.
What is the most likely diagnosis?
Medullary carcinoma
An 18-year-old female presents with 3 nodules in the right lobe of the thyroid. Clinically she is euthyroid and there is associated cervical lymphadenopathy. She has no family history of thyroid disease.
What is the most likely diagnosis?
Papillary carcinoma
List the conditions which are associated with lower-than-expected HBA1c
- Sickle-cell anaemia
- GP6D deficiency
- Hereditary spherocytosis
- Haemodialysis
List the conditions which are associated with higher-than-expected HBA1c
- Vitamin B12/folic acid deficiency
- Iron-deficiency anaemia
- Splenectomy
Describe the presentation of phaeochromocytoma
Sweating, headaches, and palpitations in association with severe hypertension
What is the most important blood test to monitor for treatment response Hashimoto’s thyroiditis?
TSH
Why is insulin only used in hyperosmolar hyperglycaemic state if the glucose stops falling while giving IV fluids?
Risk of cerebral pontine myelinolysis
What is the most common cause of hypothyroidism in the UK?
Hashimoto’s (autoimmune)
What advice should be given to women with hypothyroidism regarding levothyroxine dose in therapy?
Women with hypothyroidism may need to increase their thyroid hormone replacement dose by up to 50% as early as 4-6 weeks of pregnancy
When should you treat subclinical hypothyroidism?
If the TSH level is > 10 mU/L on 2 separate occasions 3 months apart
What is the first step in investigating hypercalcaemia?
Measuring PTH level
What is the standard HbA1c target in type 2 diabetes mellitus?
48 mmol/mol
When might the Hb1c target in T2DM be higher than 48mmol/mol?
The target may change to 53 mmol/mol if the patient is started on a second agent, or if they are receiving a medication that carries the risk of hypoglycaemia (e.g. sulphonylurea)
When should a second drug should be added in type 2 diabetes mellitus?
If the HbA1c is > 58 mmol/mol
What is the management of a thyrotoxic storm?
- Beta-blockers: typically IV propranolol
anti-thyroid drugs: e.g. methimazole or - Propylthiouracil
- Lugol’s iodine
- Dexamethasone
What blood results are associated with primary hyperaldosteronism?
Hypokalaemic metabolic acidosis
What is the mechanism of action of glitazones
- Glitazones e.g. pioglitazone are thiazolidinediones
- Increase insulin sensitivity in peripheral tissues such as adipose tissue, skeletal muscle, and the liver by binding to PPAR-γ nuclear receptor
- This results in decreased insulin resistance and improved glycaemic control
What is the first-line treatment for prolactinomas?
Dopamine agonists e.g. cabergoline
True or false: the PTH level in primary hyperparathyroidism may be normal
True
Name a contraindication for pioglitazone
Heart failure
What is the first line investigation for pheochromocytoma?
Urinary metanephrines
What standards must be met in order for a person with diabetes mellitus to drive?
- There has not been any severe hypoglycaemic event in the previous 12 months
- The driver has full hypoglycaemic awareness
- The driver must show adequate control of the condition by regular blood glucose monitoring (at least twice daily and at times relevant to driving
the driver must demonstrate an understanding of the risks of hypoglycaemia) - There are no other debarring complications of diabetes
Pepperpot skull is a characteristic X-ray finding of what condition?
Hyperparathyroidism
Increased, homogenous uptake on a radioactive iodine uptake test suggests what?
Grave’s disease
How many units are in 1ml of most standard insulin?
100
In the investigation of acromegaly, if a patient is shown to have raised IGF-1 levels, what investigation is diagnostic?
An oral glucose tolerance test (OGTT) with serial GH measurements is suggested to confirm the diagnosis
What is the mode of action of orlistat?
Orlistat works by inhibiting gastric and pancreatic lipase to reduce the digestion of fat
Clubbing (acropachy) + hyperthryoidism indicates which disease?
Grave’s
Thyrotoxicosis with tender goitre indicates what condition?
Subacute (De Quervain’s) thyroiditis
What is the most common cause of primary hyperparathyroidism?
Solitary adenoma
What blood results are associated with secondary hyperparathyroidism?
- High PTH
- Low or normal calcium
What drugs can cause gynaecomastia?
- Spironolactone (most common drug cause)
- Cimetidine
- Digoxin
- Cannabis
- Finasteride
- GnRH agonists e.g. goserelin, buserelin
oestrogens, anabolic steroids
True or false: steroids can cause psychosis
True
What blood results are associated with primary hyperaldosteronism?
- High sodium
- Low potassium
Suspected Addison’s disease. 9 am cortisol between 100-500nmol/l.
What is the next step?
9 am cortisol between 100-500nmol/l is inconclusive and requires further investigation with a short synacthen test
Hashimoto’s thyroiditis is associated with the development of what malignancy?
MALT lymphoma
What is the inheritance pattern for MODY?
Autosomal dominant
What is the treatment of choice for a toxic multinodular goitre?
Radioactive iodine
What are the clinical features of Kallmann’s syndrome?
- ‘Delayed puberty’
- hypogonadism, cryptorchidism
- Anosmia
- Patients are typically of normal or above-average height
What blood test results are associated with Kallman’s syndrome?
LH & FSH low-normal and testosterone is low
What is the most suitable oral treatment for an obese patient with T2DM if metformin fails to control diabetes?
DPP-4 inhibitor e.g. sitagliptin
Do not cause weight gain
What is the most common endogenous cause of Cushing’s syndrome?
Pituitary adenoma
An 80-year-old woman has a hip fracture. Her calcium is normal. She has never been given a diagnosis of osteoporosis.
What is the most appropriate management?
Risedronate and calcium supplements
A child presents with a palpable abdominal mass or unexplained enlarged abdominal organ.
What is the next step in management?
Refer very urgently (<48hr) for specialist assessment for neuroblastoma and Wilms’ tumour
What is the most common cause of primary hyperaldosteronism?
Bilateral idiopathic adrenal hyperplasia
What is the most appropriate treatment of gastroparesis caused by T1DM?
Metoclopramide
Over-replacement with thyroxine in patients with hypothyroidism increases the risk of what condition?
Osteoporosis
What is the first line treatment for an adrenal crisis?
IV hydrocortisone
Describe the presentation of hypercalcaemia
- Stones (renal)
- Bones (bone pain)
- Groans (abdominal pain, nausea and vomiting)
- Thrones (polyuria)
- Psychiatric overtones (confusion and cognitive dysfunction, depression, anxiety, insomnia, coma)
What type of goitre is associated with Hashimoto’s thyroiditis?
Diffuse and painless goitre
What is the first line treatment for prolactinomas?
Dopamine agonists (e.g. cabergoline, bromocriptine) are first-line treatment for prolactinomas, even if there are significant neurological complications
In DKA, once blood glucose is < 14 mmol/l, what should be started?
An infusion of 10% dextrose should be started at 125 mls/hr in addition to the saline regime
What is the definitive management of primary hyperparathyroidism?
Total parathyroidectomy
What atypical factors would prompt further tests in suspected T1DM?
Age 50 years or above, BMI of 25 kg/m² or above, slow evolution of hyperglycaemia or long prodrome
What is the first line insulin regime for newly diagnosed adults with T1DM?
Basal-bolus using twice-daily insulin detemir
What should patients with Addison’s should be given for adrenal crises?
Hydrocortisone injection kit
What gene mutation is associated with MODY?
Hepatic Nuclear Factor 1 Alpha (HNF1A)
What is a possible explanation for increased TSH levels and normal T4?
Poor compliance with thyroxine medication
How should you manage a patient with subclinical hypothyroidism with TSH level of level is 5.5 - 10mU/?
Offer patients < 65 years a 6-month trial of thyroxine if TSH remains at that level on 2 separate occasions 3 months apart and they have hypothyroidism symptoms
What fasting plasma glucose implies impaired fasting glucose?
Greater than or equal to 6.1 but less than 7.0 mmol/l
What is the definition of impaired glucose tolerance?
Fasting plasma glucose less than 7.0 mmol/l and OGTT 2-hour value greater than or equal to 7.8 mmol/l but less than 11.1 mmol/l
What is the first line treatment for most patients with a pitiutary tymour causing acromegaly?
Trans-sphenoidal surgery
What is the most appropriate investigation for patients with increased urinary cortisol and low plasma ACTH levels?
CT adrenal glands
What are the blood glucose targets for T1DM?
- 5-7 mmol/l on waking and
- 4-7 mmol/l before meals at other times of the day
At what point should a second drug (in combination with metformin) be added in T2DM?
If the HbA1c is > 58 mmol/mol
What venous blood gas results are associated with Cushing’s?
Hypokalaemic metabolic alkalosis
Name the genetic syndrome associated with insulinomas
MEN-1
If starting an SGLT-2 as initial therapy for T2DM, what should you do?
Ensure metformin is titrated up first
C-peptide levels are typically (high/low) in patients with T1DM
Low
What is the single most useful test initial for determining hypercalcaemia?
PTH
Describe the administration of insulin in DKA
Insulin should be fixed rate whilst continuing regular injected long-acting insulin but stopping short actin injected insulin
What is the first line treatment for Grave’s disease?
Carbimazole (12-18 months)
What is the major complication of carbimazole therapy?
Agranulocytosis
What is the prognosis of papillary thyroid cancer?
Shows excellent prognosis, despite the tendency to spread to cervical lymph nodes early
What is pretibial myoedema?
Incommon but specific feature in Grave’s disease that is not seen in hyperthyroidism secondary to other causes
Name two invesigations which can be used to differentiate between T1 and T2DM
C-peptide levels and diabetes-specific autoantibodies
