Endocrinology Flashcards
What is Sheehan’s syndrome?
- Infarction of the pituitary gland secondary to profound blood loss during postpartum.
- Most common consequence is disruption of the production of growth hormone and prolactin causing agalctorhea, but can affect other hormones in the anterior pituitary.
First line management in Type 2 DM ?
Metformin , up titrate, if contraindicated due to CVD than SGLT-2 inhibitor. if contraindicated for different reason than DPP-4
Second line management for Type 2 DM ?
Add on one of in addition to metformin:
- DPP-4 inhibitor
- pioglitazone
-Sulfonylurea
- SGLT 2 inhibitor
Third line management for DM type 2
Add a third one from the below :
- DPP-4 inhibitor
- pioglitazone
-Sulfonylurea
- SGLT 2 inhibitor
Or start Insulin
If third line therapy for DM is not sufficient , what is next?
Insulin or GLP2 mimetic if BMI >35 or insulin would have occupational implications.
How do you distinguish PCOS from non-classical congenital adrenal hyperplasia on bloods?
- Clinical features are very similar - hirsutism, acne, irregular periods, early periods.
- Biochemically both will show elevated testosterone however Non-classical congenital adrenal hyperplasia, will also show elevated 17-hydroprogensterone.
- PCOS usually develops after puberty not during
What is pseudohypoparathyroidism?
It is a condition in which target cells are being insensitive to PTH, due to abnormality in the G protein.
- Clinical manifestations include : low IQ, short stature, shortened 4th and 5th metacarpals.
- Biochemistry - low calcium, high phosphate and high PTH
- Diagnosed via measuring urinary cAMP and phosphate following infusion of PTH.
-> In hypoparathyroidism neither cAMP n
or phosphate levels will increase.
-> In pseudohypoparathyroidism type 1 neither cAMP nor phosphate levels are increased.
- > In pseudohypoparathyroidism type 2 only cAMP rises
- Treatment is calcium and vitamin D supplementation
Criteria for offering parathyroidectomy even to patients with primary asymptomatic hyperparathyroidism?
-Serum calcium 0.25mmol/L above the upper limit
- eGFR < 60
- Current or previous nephrolithiasis or nephrocalcinosis
- Osteoporosis - T score < or = to - 2.5
- Age less than 50
What are the amino acid modifications seen in glargine insulin?
- Insulin glargine is a long acting insulin analogue, such as detemir. - – The main use for insulin analogues is in improving glycaemic control in type 1 diabetes. Some patients may be limited in HbA1c reductions due to post meal hypoglycaemia, or nocturnal hypoglycaemia, this is where long acting insulins help as they keep a steady state.
- Glycine is at position A21, two arginine are added to the B chain
Medication linked to SIADH ?
- Vincristine,
- vinblastine
- cyclophosphamide
- chlorpropamide
- clofibrate
- phenothiazines
- Monoamine oxidase uptake inhibitors.
Criteria for diagnosis of SIADH?
- normal renal , adrenal and thyroid function, with hyponatraemia and hypotonic plasma ( <270)
- urine sodium should be inappropriately high and there should be excessive renal sodium loss of at least 20mmol/L
Why is hypercalcaemia seen in sarcoidosis?
- It is due to uncontrolled synthesis of 1.25-dihydroxyvitamin D3 by macrophages, 1.25-dihydroxyvitamin D3 leads to an increased absorption of calcium in the intestine and an increased resorption of calcium in the bone.
MEN type 1
3Ps
- Parathyroid (95%) - hyperparathyroidism due to parathyroid hyperplasia
- Pituitary (70%)
- Pancreas (50%) - insulinomas or gastrinoma e.g Zollinger-Ellison syndrome
=> MEN 1 gene
MEN type II a
Medullary thyroid cancer in 70%
+ 2Ps
-> parathyroid (60%)
-> phaeochromocytoma
=> RET oncogene
MEN type IIb
Medullary thyroid cancer + 1P
-> Phaeochromocytoma
+ Marfanoid body habitus , neuromas
=> RET oncogene
What is a craniopharyngioma and what are some hallmark features ?
- It is slow growing calcified cystic tumour arising from the remnants of the craniopharyngeal duct.
- Symptoms usually develop when the tumour is 3cm diameter or bigger.
- Most common symptoms are growth failure and delayed puberty from compression of the anterior pituitary.
- Radiologically common feature - suprasellar calcified cyst, with calcification being more common in children compared to adults
Best test to confirm medullary thyroid carcinoma?
Pentagastrin test - pentagastrin is a synthetic peptide - that simulates gastrin, prompting prodduction of calcitonin from the thyroid gland, in medullary thyroid cancer the C cells are neoplastic so they overproduce calcitonin.
The best way to distinguish between infesction and charcot’s arthropathy?
Indium-labelled white cell scan
Charcot’s , why and what to do?
Charcot’s is thought to occur due to increased blood flow as a result of neuropathy. This results in increased osteoclast activity and bone turnover; the foot is then susceptible to often very minor trauma and destructive changes take place. Experts recommend immobilisation for at least 3 months in an aircast-type non-weight-bearing plaster. This is to allow bone remodelling/repair to occur. Bisphosphonates are a useful adjunct to the healing process as they reduce osteoclast activity. Whilst insulin therapy is likely to improve glycaemic control and slow further progression of neuropathy, it will not affect recovery of the Charcot’s joint
What does TP- ALB stand for ?
TP-ALB stands for:
TP = Total Protein
ALB = Albumin
So, TP-ALB refers to the globulin fraction, which is calculated by subtracting albumin from total protein:
Globulin = Total Protein – Albumin
An elevated TP-ALB (i.e., raised globulin fraction) suggests hyperglobulinaemia, commonly seen in multiple myeloma due to excess monoclonal immunoglobulin production.
Subacute thyroiditis treatment and diagnostic features?
- malaise and neck pain radiating to the ear or head.
- gland is tender and nodular on palpation
- Elevates ESR
- Technetium-99m scan shows no technetium uptake by the thyroid gland.
- Mild cases can be treated by NSAID with more severe cases causing thyrotoxicosis treated with prednisalone, which can be stopped once the T4 normalises.
Indications for elective parathyroid surgery ?
- serum Ca²⁺ level > 0.25 mmol/l above the upper limit of normal
- marked hypercalciuria (> 400 mg/day) or renal stones
- creatinine clearance < 30% of normal
- marked bone density reduction with a T-score < 2.5 at any site
- age < 50 years (if the problem is left untreated, many of these younger patients eventually develop complications of primary hyperparathyroidism)
- a patient for whom surveillance and follow-up are difficult or impossible.
Management in acute prathryoidism with high calcium and high PTH?
Levels of calcium above 3.5 are associated with cardiac arythmias, coma, pancreatitis. The treatements includes agressive re-hydration following which IV bisphosphonates - pamidronate being the treatment of choice.
- Emergency surgery is only considered when the above has shown to be inefective.
What is McCune-Albright syndrome and what are the cardinal features?
McCune-Albright syndrome is not inherited, it is due to a random, somatic mutation in the GNAS gene.
- Features
- precocious puberty
- cafe-au-lait spots
- polyostotic fibrous dysplasia
- short stature
