Endo Flashcards
Electrolyte abnormalities in addisonian crisis
HypoNa, Hyper K
Late feature: hypoglycaemia
What are the typical LDL, HLD and TG findings in patients with diabetes?
TG elevated
HDL and LDL are low or normal
Aromatase converts testosterone to estradial T/F
T
In a pt with T1DM doing sick day dosing should the lantus be increased or decreased?
Increased - will have increased insulin requirements in the setting of an acute illness
During puberty breast enlargement occurs in about 10% of males T/F
F - occurs in 40-60% of males, it is due to metabolism of testosterone, usually resolves in 2-3 years and does not need treatment
Dawn phenomenon is due to noctural hypoglycaemia and subsequent rebound hyperglycaemia in the early morning T/F
F - this is the description of smogyi effect, features of noctural hypoglycaemia (nightmares, tremors and rarely sz, early am headaches)
Dawn phen - early am hyperglycaemia from growth hormone secretion, peaks around 0400 - 0500. Can tx with increased insulin dosing
In pts with DM growth spurt leads to hypo or hyperglycaemia?
Hyperglycaemia and increased insulin requirements
Precocious puberty in males often has a pathological cause T/F
T - 80%
What is the most common enzyme deficiency causing congenital adrenal hyperplasia?
Deficiency in 21-hydroxylase
Enzyme 21 hydroxylase converts what to what?
17OH progesterone to 11 deoxycortisol
Hence in deficiency will get a build up of 17OHP and a low 11 deoxycortisol. However levels of 17OHP are elevated in normal infants in the first 1-2 days of life, especially so if they are premature or ill.
Most reliable way to diagnosis 21 hydroxylase def?
Measure 17OHP at baseline and then 30, 60 min after admin of ACTH
What is the second most common enzyme def leading to congenital adrenal hyperplasia?
Clinical features?
11 beta hydroxylase def (converts 11deoxycortisol to cortisol)
Features:
Signs of androgen excess (2ndary sex characteristics w/o testicular enlargement)
HTN
Do not have adrenal crisis
First sign of puberty in girls?
Breast development
First sign of puberty in boys?
Increase in testicular volume
Time from onset of puberty to menarche is usually? What SMR does menarche usually occur?
4 yrs or less
SMR 4
In treatment of DM how often is insulatard dosed?
Twice daily
Patient on TID steroids is prescribed carbamazepine what adjustment needs to be made to the steroids?
Increase each dose of steroids
When is the peak incidence of type 1 DM?
When children start school 5-7 yrs and at puberty 10 -14 yrs
Note: there is an increased incidence after Coxsackie virus, mumps and rubella epidemics suggesting that initial viral infection triggers an autoimmune response against the islet cells. There is a seasonal variation with peaks in the autumn and winter months
T1DM is associated with an increased risk in siblings T/F
T - 1-7% risk
How often should HbA1c be checked in pts with T2DM?
every 3 months (remember life cycle of RBC is 3 months)
What are the two most common causes of acquired hypothyroidism?
Hashimotos thyroiditis
Post total body irradiation (part of the prep for bone marrow transplant)
Causes of elevated creatinine in DKA?
Dehydration
Falsely elevated Cr as the ketones interact with the Jaffe method
What physical exam finding in a male helps to differentiate central from peripheral causes of precocious puberty?
Peripheral: secondary sexual characteristics in a boy with pre-pubertal testes
Central: secondary sexual characteristics + bilaterally enlarging testes
Growth hormone deficiency has what effect on bone age?
Causes a delay in bone age
Hypothyroidism also causes a delay
What lab abnormality can been seen on sulphonylurea overdose?
Increased C peptide – stimulation of beta cells to produce both c peptide and insulin
Note in exogenous insulin OD there will be decreased C peptide
What is the risk of T1 DM in a patient who’s identical twin has type 1 DM?
30-50%
Note: glutamic acid decarboxylase, islet cell or islet tyrosine phosphatase 2 (IA-2) antibodies will increase the risk
What % of patients with T1 DM also have celiac disease?
Around 10%
Compared to untreated children by how much does growth hormone increase final height?
3-4 cm
Parathyroid hormone is secreted in response to what?
Low levels of iCal in the blood
What is the role of parathyroid hormone?
To increase renal Ca absorption and mobilise Ca and phosphate from the bone
MEN1 is associated with mucosal neuromas T/F
F MEN 2b is associated with mucosal neuromas
MEN 1 is associated with pit adenoma, parathyroid tumors and pancreatic tumors
Somatostatin has what effect on growth hormone?
Inhibits release of growth hormone
Factors that increase secretion of growth hormone?
Hypoglycaemia
Mod to high intensity exercise
Stress due to emotional disturbances, illness or fever
Dopamine agonists such as bromocriptine
Cortisol is a counter regulatory hormone of?
Insulin –> it has the opposite effects of insulin.
Hence cortisol increases gluconeogenesis, hepatic glycogenolysis and ketongensis
One of the main mechanisms of action of insulin is to induce translocation of the preformed GLUT 4 transporter to the cell surface. T/F
T - then insulin binds to the transporter which generates a signal within the cell to stimulate glucose conversion to glucose-6-phosphate and terminates metabolism or storage of the glucose molecule