Endocrinology tutorials Flashcards
What is a worrying change?
Crossing centiles
Define 25% centile in terms of short stature
- Centile (percentile) is a measure used in statistics indicating the value below which a given percentage of observations in a group of observations falls
- 25% of individuals have a shorter stature and 75% of individuals have a taller stature
Causes of short stature
- endocrinal (growth hormone deficiency, hypothyroidism, vitamin D deficiency, Cushings from excess circulating cortisol in the body)
- nutritional(malnutrition)
- syndromes (Downs)
- Constitutional growth and puberty delay
- Systemic illness (affects the entire body)
- emotional/psychological deprivation
- dysplasia (skeletal dysplasia=dwarfism)
- genetic conditions
-often emotional and nutritional causes are classified together
GH stimulation test
- Growth hormone stimulation test
- IV (intravenous) line inserted into a vein in your arm or hand
- initial blood sample taken
- GH stimulated added into the body through the IV line (insulin to reduce blood glucose levels)
- Blood samples are then taken at regular intervals through the same IV line
- Blood samples then analysed to see if the expected amount of GH (growth hormone) was produced in response to the stimulant
Difference between insulin and growth hormone
- growth hormone counteracts insulin effects on blood glucose levels
- insulin decreases the blood glucose levels
- growth hormone increases the blood glucose levels
- we stimulate growth hormone release when insulin concentrations are low=protection against hypoglycaemia
Cushing’s Syndrome
- excess circulating cortisol
- high BMI accompanied with short stature as diagnostic factors
Define polydipsia
Extreme thirst
Define polyuria
Increased/excessive urine production (large volumes of urine)
Define symptom
Patient complaint
Define sign
What you find on examination
Expected pattern in the osmolality of urine during the water deprivation test (type of biochemical test)
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DDAVP and its impact on the osmolality of urine
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Underlying causes of cranial diabetes insipidus
- tumour (malignancy)
- head trauma
- infection
- inflammation
Investigations for diabetes insipidus
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Causes of weight loss
- Hyperthyroidism
- Diabetes
- Cancer
- Eating disorders
- Infection
Surrogate marker for insulin measured
- Insulin has low half life and is not a stable molecule so cannot be measured
- Measure C-peptide
- C-peptide was part of the proinsulin molecule and was cleaved for co-secretion with insulin from the pancreas (secretion from the pancreas at the same time)=more stable with a longer half life
Define angina pectoris
chest pain
Steps to reduce the risk of cardiovascular disease
- Exercise
- Control hypertension (high blood pressure)
- Statins to address LDL cholesterol
- Diet
- Reduce BMI (body mass index)
Why do we get glycosuria?
- Insulin deficiency leads increased glycogenolysis and gluconeogenesis (inability to inhibit these processes) so the patient becomes hyperglycaemic
- blood glucose levels exceed the renal reabsorptive capacity
Why do we get polyuria?
-Hyperglycaemia leads to osmotic diuresis
Define glycosuria
Presence of glucose in the urine
Define diabetes
Where the fasting blood glucose is more than 7 mmol/L or the random glucose is more than 11 mmol/L
-Values were decided from evidence of diabetic retinopathy (damage to the back of the eye from high blood sugar levels)
Impaired fasting blood glucose levels for prediabetes
6mmol/L- 7mmol/L (more than 6 is abnormal and requires monitoring)
Impaired random blood glucose levels for prediabetes
7.8mmol/L-11.0mmol/L
