Endocrinology Flashcards
(136 cards)
What is T1DM?
Characterised by hyperglycaemia due to absolute insulin deficiency; most cases result from autoimmune pancreatic beta-cell destruction in genetically susceptible individuals. Usually presents with acute symptoms or ketoacidosis in childhood or adolescence.
What is T2DM?
Characterised by insulin resistance and relative insulin deficiency; most patients are asymptomatic and are diagnosed through screening (abnormal fasting plasma glucose, HbA1c, and/or oral glucose tolerace test)
How does T1DM present?
Hyperglycaemia (random plasma glucose >11mmol/L)
Polydipsia, polyuria
Usually young age
Weight loss
Blurred vision
Diabetic ketoacidosis (nausea, vomiting, abdominal pain, clinical dehydration, tachypnoea)
Lethargy
Coma or altered mental state (uncommon)
What are the risk factors for T1DM?
Genetic predisposition (family history of autoimmune diseases)
How is diabetes mellitus investigated?
Random plasma glucose (≥11.1 mmol/L confirms diagnosis in presence of symptoms of polyuria, polydipsia, and unexplained weight loss)
Fasting plasma glucose (no caloric intake for >8 hours, ≥7.0 mmol/L)
2-hour plasma glucose (2 hours after 75g oral glucose load, ≥11.1 mmol/L)
HbA1c (reflects degree of hyperglycaemia over the preceding 3 months, ≥6.5% or 48 mmol/L)
How is T1DM treated in children and non-pregnant adults?
Basal bolus insulin (1st line)
Metformin (consider if adult with BMI >25 kg/m^2)
Fixed dose insulin is second line
How is T1DM treated in pregnant women?
Basal bolus insulin
Consider metformin (when insulin resistant, as well as insulin deficient, or BMI ≥25 kg/m^2)
Low-dose aspirin (from 12 weeks till birth of baby - reduces risk of pre-eclampsia)
What are some common symptoms of T2DM?
Asymptomatic
Candidal infections (most commonly vaginal, penile, or in skin folds)
Skin infections (cellulitis or abscesses)
Urinary tract infections (cystitis or pyelonephritis)
Fatigue (may be early warning sign of CVR disease - clinicians should have low threshold for cardiac evaluation)
Blurred vision
What are some uncommon symptoms of T2DM?
Polydipsia and polyuria (only occurs with considerable hyperglycaemia, FPG >16.6 mmol/L and/or HbA1c >95 mmol/mol)
Polyphagia (excessive appetite)
Unintentional weight loss (if marked hyperglycaemia)
Paraesthesias (abnormal sensation, prolonged undiagnosed diabetes resulting in neuropathy)
Acanthosis nigricans (most often associated with obesity)
What are some risk factors for T2DM?
- Older age
- Overweight/obesity
- Gestational diabetes
- Non-diabetic hyperglycaemia (pre-diabetes)
- Family history
- Non-white ancestry
- PCOS (elevated risk; should be periodically screened for diabetes)
- Hypertension
- Dyslipidaemia (especially with low HDL and/or high triglycerides)
- Cardiovascular disease
- Stress
What is the management of T2DM?
FIRST LIFESTYLE
1. Metformin (with SGLT-2 if chronic heart failure or risk of CVD)
Switch to modified release metformin if side effects (e.g. GI)
2. Add sulfonylurea or DPP-4 inhibitor or pioglitazone
What are the side effects of metformin?
GI symptoms: pain, nausea, diarrhoea
Lactic acidosis with severe renal disease or renal failure
What are the contraindications for metformin?
CKD
recent myocardial infarction, sepsis, acute kidney injury and severe dehydration (can cause lactic acidosis)
Alcohol abuse
What are the side effects of SGLT-2?
Glycosuria
Increased urine output and frequency
Genital and urinary tract infections (e.g., thrush)
Weight loss
Diabetic ketoacidosis, notably with only moderately raised glucose
Fournier’s gangrene (rare but severe infection of the genitals or perineum)
What are the side effects of pioglitazone?
Weight gain
Heart failure
Increased risk of bone fractures
A small increase in the risk of bladder cancer
What are the side effects of sulfonylureas?
Weight gain
Hypoglycaemia
What is Addison’s disease?
Destruction of the adrenal cortex and subsequent reduction in the output of adrenal hormones, i.e. glucocorticoids (cortisol) and/or mineralocorticoids (aldosterone)
AUTOIMMUNE
How is cortisol release regulated?
The pituitary gland releases ACTH, which triggers adrenal cortex to secrete cortisol
Elevated cortisol levels suppress ACTH in a negative feedback loop
How does Addison’s disease present?
Fatigue (lethargy, weakness, or tiredness)
Anorexia and weight loss
‘Salt craving’ - hyponatraemia and hyperkalaemia
Hyperpigmentation (MSH is also produced with ACTH, same precursor of POMC)
Nausea, vomiting - may have adrenal crisis
Postural hypotesion
Muscle cramps and joint pains
What are the risk factors for Addison’s disease?
Female sex
Adrenal haemorrhage (patients taking anticoagulants are at increased risk)
Autoimmune diseases
Coeliac disease
Adrenocortical autoantibodies
How is Addison’s disease investigated?
Morning serum cortisol (<140 nanomols/L abnormal)
Plasma ACTH (>12 picomols/L)
U&Es (hyponatraemia, hyperkalaemia)
ACTH stimulation test
How is Addison’s disease treated?
Oral glucocorticoid and mineralocorticoid replacement therapy
(hydrocortisone/cortisone/prednisolone and fludrocortisone)
How is an adrenal crisis treated?
Intravenous hydrocortisone
Saline to correct dehydration and hypotension
Glucose, when necessary, to correct hypoglycaemia
What is Cushing’s disease?
Excessive cortisol production as a result of excessive ACTH from the pituitary gland