Endocrine Flashcards
(291 cards)
1
Q
What is the other term for primary adrenal insufficiency?
A
Addison’s disease
2
Q
What does Addison’s disease cause?
A
Reduced production of glucocorticosteroids e.g. cortisol and mineralocorticoids e.g. aldosterone, and adrenal androgens
The absence of cortisol leads to increased production of adrenocorticotrophic hormone (ACTH) because negative feedback to the pituitary gland is reduced.
3
Q
In the UK what is the most common cause of Addisons disease?
A
Autoimmune disease - 70-90% of cases - in 60% of these cases it is a multi-organ autoimmune polyendocrine syndrome
4
Q
Worldwide, what is the most common cause of Addisons disease?
A
Infection - tuberculosis
5
Q
Which two other autoimmune conditions are associated with Addisons disease (in about 50% of people)?
A
- Type 1 diabetes
2. Hypothyroidism
6
Q
What is polyglandular autoimmune syndrome type 1 a triad of?
A
- Addisons disease
- Hypoparathyroidism
- Chronic candidiasis (fungal infections)
7
Q
What is polyglandular autoimmune syndrome type 2?
A
This is more common than type 1, and is a complex genetic trait with links to HLA major histocompatibility - HLA DR3 and DR4
- Usually involves Addisons disease, thyroid disease and T1DM
(can also be associated with vitiligo, vitamin B12 deficiency, coeliac disease and hypoparathyroidism)
8
Q
What is the most serious complication of Addisons disease?
A
Adrenal crisis - when the adrenal glands can’t supply the extra corticosteroids needed to cope with physical stress and life-threatening symptoms develop - severe dehydration, hypotension, hypovolaemic shock, altered consciousness, seizures, stroke or cardiac arrest
9
Q
What are the typical features of Addison’s disease? (6)
A
- Anorexia, weight loss
- Dizzy, syncope
- Postural hypotension
- Bronze skin and pigmented palmar crease
- Fatigue, depression
- Nausea, vomiting, abdominal pain, diarrhoea or constipation
10
Q
What are the three key features of DKA?
A
- Hyperglycaemia >11mmol/L (often >30)
- Positive ketones on dipstick or fingerprick
- Metabolic acidosis pH <7.3
11
Q
What is the clinical presentation for DKA? (7)
A
- Polyuria
- Polydipsia
- N&V
- Weight loss
- Confusion and drowsiness
- Kussmaul breathing (deep hyperventilation)
- Vague abdominal pain
12
Q
What investigations are carried out for DKA?
A
- Urine dipstick +++ ketones ++ glucose
- Blood glucose
- Capillary ketones >3mmol
- ABG - metabolic acidosis
- Bloods - FBC, U&Es, LFTs
13
Q
What is the management for DKA? (4)
A
A-E assessment
- Fluid regimen
- Insulin - 50 units of act rapid with 50ml saline - fixed rate 0.1 units/kg/hour
- Once glucose <14, start 10% glucose
- K+ sulphate (must never give >10mmol K+ over 1 hour)
14
Q
What does HONK AKA HHS refer to?
A
Hyperglycaemic hyperosmolar non-ketotic state
15
Q
What is HHS?
A
A severe uncorrected hyperglycaemia in the presence of residual insulin production (T2DM) leading to dehydration but not ketoacidosis
16
Q
What is the concern/risk with HHS?
A
High risk of thrombosis
17
Q
What are the precipitants for HHS? (8)
A
- Infection
- MI
- CVA
- GI bleed
- Poor med compliance
- High sugar diet
- Neglect
- Diuretics/BBs/Antihistamines
18
Q
How can HHS present? (5)
A
- Unknown history of diabetes
- Insidious onset of polyuria and polydipsia
- Severe dehydration
- Weakness, leg cramps and visual disturbances
- Reduced consciousness - related to plasma osmolality (>440 = coma)
19
Q
What is the management for HHS?
A
- A-E assessment
- Fluid replacement - half the rate of DKA e.g. 1 litre of saline over 30 minutes, then 1 litre + potassium every 2-4 hours
- Treat causes e.g. infection
- Thromboprophylaxis e.g. LMWH
only if ketonuria - then insulin infusion
20
Q
What happens in the body with Addisons disease, as a result of low aldosterone?
A
- Hyperkalaemia
- Hyponatraemia
- Hypovolaemia
- Metabolic acidosis
21
Q
How does hypoglycaemia tend to present? (7)
A
- Sweating
- Pallor
- Tachycardia/palpitations/anxiety
- Confusion
- Slurred speech/blurred vision
- Seizures
- Coma
22
Q
What is the management for hypoglycaemia?
A
- ABCDE
- Blood guclose - before glucose administration!
- GCS 15 and safe swallow = fast acting glucose 10-20g orally in frequent and small doses, recheck blood glucose 10-15 mins after and repeat if not >4mmol
- When patient can eat give carbohydrate rich snack
- If alcoholic - consider pabrinex
23
Q
What happens if the patient with hypoglycaemia cannot take oral glucose e.g. if GCS <15?
A
Give IV 100mls of 20% glucose or 50ml of 50%. If IV access is unattainable then give IM glucagon 1mg.
24
Q
What are the two main types of diabetes insulin treatment regimen?
A
- Premix
2. Basal-bolus
25
What are the names of the premix drugs?
1. Humalog mix 25
2. Humalog mix 50
3. Humalog M3
4. Novomix 30
the numbers refer to the % of short-acting insulin in each mix
26
In general, how many grams of carbohydrate are recommended for 1 unit of insulin?
10 grams
27
In general, what can the correction be for 1 unit of insulin, in terms of capillary blood glucose?
1 unit of insulin can equate to for example 3mmol/L of capillary blood glucose
28
How is type 1 diabetes investigated, what is the test?
Oral glucose tolerance test - 75g of glucose is given to a fasting patient, the baseline fasting glucose is measured and then 2 hours post glucose load.
29
What is the expected fasting blood glucose for a person without diabetes and with diabetes?
Without - <6
| With - >6
30
What is the expected 2h post-glucose load for someone with and someone without diabetes?
Without - <7.8
| With - >11.1
31
What are the macrovascular complications of diabetes?
CVA, MI, peripheral vascular disease
32
What are the microvascular complications of diabetes?
Retinopathy, nephropathy and neuropathy
33
What causes type 1 diabetes?
It is an autoimmune destruction of beta cells in the islets of langerhans, leading to absolute insulin deficiency.
34
There is a strong association with which HLA types and T1DM?
HLA-DR3 and DR4
35
What is the peak age of onset for T1DM?
Age 12
36
What are the classic symptoms associated with T1DM? (4)
1. Polyuria
2. Polydipsia
3. Weight loss
4. sometimes DKA is the presenting feature
37
What investigations are important to request/perform when someone presents with the symptoms indicative of T1DM? (4)
Bloods - FBC, U&Es, glucose, antibodies
Immunology - anti-islet cell Ab, anti-GAD Ab
Urine - ketones
ABG
38
Which annual reviews need to be performed in someone with diabetes? (9)
1. Weight + BMI
2. Creatinine
3. Urinary ACR
4. Cholesterol
5. HbA1c (biannual)
6. BP (aim <140/90)
7. Smoking status
8. Fundoscopy
9. Feet examination
39
In addition to the annual reviews, what else needs to be checked more regularly in people with T1DM? (4)
1. Injection sites
2. BP monitoring
3. Renal function
4. Thyroid function
40
What are the complications of DKA? (5)
1. Cerebral oedema
2. Hypoglycaemia
3. Hypokalaemia
4. Hyperkalaemia
5. Pulmonary oedema
41
What are the 4 different classes of drugs used in the treatment of T2DM?
1. Biguanides (metformin)
2. Sulphonylureas (gliclazide, glimepiride)
3. Thiazolidinediones (rosiglitazone)
4. alpha-Glucosidase inhibitors (acarbose)
42
What is the mechanism of action of metformin (biguanides)?
Improves the body's sensitivity to insulin
43
What is the mechanism of action of sulphonylureas?
Stimulates the pancreatic insulin release
44
What is the mortality rate as a % for people who experience HONK/hyperosmolar non-ketotic coma/HHS?
20-40%
45
What are the triggers for hypoglycaemia?
1. Sulphonylureas
2. Alcohol/Addison's
3. Insulinomas/insulin/infection
4. Liver failure
SAIL
46
What are the signs/symptoms that can indicate hypoglycaemia? (8)
1. Cold sweat
2. Fatigue
3. Irritability
4. Confusion
5. Loss of consciousness
6. Collapse
7. Tachycardia
8. Seizures
47
Which hormones do the posterior pituitary gland produce? (2)
1. ADH
| 2. Oxytocin
48
Which hormones are produced by the anterior pituitary gland? (6)
1. ACTH - adrenocorticothrophic hormone
2. TSH
3. LH
4. FSH
5. GH
6. Prolactin
49
Why does insulin resistance in T2DM lead to heart disease and stroke?
Insulin resistance has pro-thrombotic effects leading to a higher risk of emboli in coronary arteries
50
In addition to insulin resistance, what are the other two components than contribute to diabetic heart disease?
1. Coronary atherosclerosis - due to smoking, poor diets, hypertension and damage to vessels from glucose
2. Metabolic syndrome - large waistline, triglycerides
51
How is the risk of diabetic heart disease managed? (3)
1. Lifestyle changes - smoking cessation, diet and exercise advice
2. Statins
3. Anti-hypertensives
52
If someone is on metformin but their HbA1c is still greater than 58mmol/mol (7.5%), what is the next step in treatment?
Add a gliptin or sulphonylurea
53
What treatment can be used to protect the kidneys in someone at risk of diabetic nephropathy?
Either an ACE inhibitor or losartan - even if BP is normal, as they inhibit RAAS
54
What is the primary cause of adrenal insufficiency?
Addison's disease - autoimmune destruction of the adrenal gland. (typically 30-50 year old females)
55
Destruction of the adrenal cortex results in which adrenal hormones not being produced? (3)
1. Mineralcorticosteroids (aldosterone)
2. Glucocorticosteroids (cortisol)
3. Androgens (mildly testosterone - mainly produced in the testes)
56
What are the two main categories of diabetic foot problems?
1. Neuropathy
| 2. Ischaemia
57
What is the condition that can occur in foot neuropathy?
Charcot foot/joint
58
What is Charcot foot AKA Charcot arthropathy?
Charcot arthopathy is a serious condition, more common if people lose feeling in their feet. The bones in the foot can become weak and lead to dislocations, fractures and changes in the shape of the foot or ankle. It can develop in diabetes, and if it is not treated quickly, ulcers or other sores can develop.
59
What are the symptoms of Charcot arthropathy?
Foot feeling hot, painful and looking swollen or red. Additionally they will lose function, the arch may collapse and neuropathy may occur
60
What is the management of suspected Charcot arthropathy?
Referral to an MDT foot service within 1 working day, do not put any weight on that foot until the appointment and normally the person will receive X-rays/MRI scans. Treatment includes having a plaster cast fitted.
61
What are the typical features of Addison'sdisease?
It is often diagnosed late due to the vague symptoms that can present.
Lead + tired: anorexia, weight loss, dizzy, syncope, postural hypotension
Tanned: bronze skin, pigmented palmar crease + buccal mucosa
Tearful + wear: fatigue, depression, low self-esteem, psychosis
GI: nausea, vomiting, abdominal pain, diarrhoea or constipation
62
What are in the kidneys that act as receptors to ADH?
Aquaporins
63
Drinking water does has what effect on plasma osmolality?
Decreases plasma osmolality (diluting blood with water)
64
What happens when there is decrease in plasma osmolality due to an increase in water intake?
The hypothalamus tells the pituitary gland to not produce as much ADH, so that more water can be excreted in the urine (dilute urine)
65
What happens if ADH continues not to be released, even if the plasma osmolality has returned to normal?
The body recognises that the blood is getting dilute with water as it takes up more space in vessels, and causes aldosterone to stop being released. Less aldosterone floating around in the blood causes sodium to be released into urine. Concentration gradients cause water to follow the sodium, which normalises the water volume in the blood.
66
What is the problem with our body regulating water through aldosterone and sodium output?
The sodium is released into the urine from the blood, yet the sodium was already low in the blood to begin with. This means plasma sodium osmolality is dropping significantly. This is SIADH.
67
There are four patterns of SIADH, what are the 4 types?
Type A - erratic, independent of plasma osmolality. ADH levels tend to be very high, so the maximum amount fluid is retained, causing urine osmolality to be very high too.
Type B - constant release of moderate amount of ADH
Type C - this is when the baseline plasma concentration of sodium level is set lower than normal. This type is unique as the plasma sodium concentration is stable, but low.
Type D - ADH secretion is normal yet urine osmolality is still high
68
What are the symptoms of SIADH caused by?
Low sodium levels
69
What are the symptoms of SIADH? (5)
1. Headache
2. Nausea and vomiting
3. Muscle cramps
4. Tremors
5. Cerebral oedema - hallucinations, mood swings, confusion
70
If SIADH symptoms are missed, what are the potential serious complications? (3)
1. Seizure
2. Coma
3. Death
71
What would indicate SIADH using blood test results?
1. Low blood sodium
2. Low plasma osmolality
3. High urine osmolality
4. High urine sodium
72
What are the causes of SIADH?
Anything that disrupts the secretion of ADH.
1. Stroke, haemorrhage, trauma to the brain
2. Drugs - mood stabilisers or anti-epileptics
3. Surgery
4. Ectopic ADH release by tumours - small cell carcinoma
5. Family history
73
What is the treatment for SIADH?
Treat the underlying cause, but also restricting fluid and increasing salt and protein in the diet.
Drugs that can inhibit ADH secretion can also work.
74
What the other term used to describe a hyperthyroid crisis?
A thyrotoxic storm
75
What are the symptoms of a thyrotoxic storm?
1. Tachycardia
2. Raised temperature
3. Hypotension
4. Confusion
76
What is the treatment for a thyrotoxic storm?
1. Beta blockers
2. Propylthiouracil (an anti-thyroid treatment to help reduce the effect of raised serum thyroid hormones)
3. Hydrocortisone - treat any underlying adrenal insufficiency which is more common in patients suffering form hyperthyroidism and can also help reduced the serum thyroid hormone levels
77
6% of people with acromegaly have what inherited syndrome - characterised by the occurrence of tumours in the parathyroid, pituitary and adrenal glands?
MEN-1
78
What are the features of acromegaly? (5)
1. Coarse facial appearance
2. Spade-like hands
3. Increase in shoe size
4. Large tongue
5. Excessive sweating and oily skin
79
What are the complications of acromegaly? (4)
1. Hypertension
2. Diabetes (>10%)
3. Cardiomyopathy
4. Colorectal cancer
80
What is the first line antihypertensive drug for all people with diabetes?
ACE inhibitors
81
What is the most likely diagnosis for an older female patient with polydipsia, polyuria, inappropriately normal or raised parathyroid hormone level and a raised calcium?
Primary hyperparathyroidism - 80% solitary adenoma
82
What are the symptoms of raised calcium? (6)
Bones, stones, abdominal groans and psychic moans
1. Polydipsia, polyuria
2. Peptic ulceration/constipation/pancreatitis
3. Bone pain/fracture
4. Renal stones
5. Depression
6. Hypertension
83
What might be found on investigation for hyperparathyroidism?
1. Raised calcium, low phosphate
2. PTH may be raised or normal
3. Pepperpot skull is characteristic X-ray finding of hyperparathyroidism
84
What is the name for the appearance of lytic lesions in the brain associated with multiple myeloma?
Raindrop skull
85
What % of primary hyperparathyroidism are caused by parathyroid adenoma?
80%
86
What is the mechanism of action of empagliflozin - an SGLT-2 inhibitor?
It increases urinary glucose excretion - which causes the following side effects: increased urine output, weight loss and risk of UTIs
87
What is the recommended amount of carbohydrate to treat a hypoglycaemic state?
10-20grams
88
What can be given to someone in a hypoglycaemic state?
- If they have a safe swallow and normal GCS, Lucozade, glucose gel or tabs to chew.
- If reduced GCS - IV access is preferred to give 20% glucose approx. 50-100ml (don't give 50% as it damages veins)
- Last resort is IM glucagon (high chance of inducing sickness so not recommended unless vital)
89
What are the signs of a hypoglycaemic state? (8)
1. Palpitations
2. Shaking
3. Hunger
4. Irritability
5. Headache
6. Sweating
7. Dizziness
8. Unconscious
90
What is hyperparathyroidism?
When there is excessive sections of parathyroid hormone from the parathyroid glands located in the neck.
91
What are the parathyroid hormone do?
Regulates serum calcium and phosphate levels and also plays a part in bone metabolism
92
What are the different types of parathyroidism?
1. Primary - one parathyroid gland (or more) produces excess PTH. This may be asymptomatic
2. Secondary - there is increased secretion of PTH in response to low calcium because of kidney, liver or bowel disease
3. Tertiary - there is autonomous secretion of PTH, usually because of CKD
93
What does the parathyroid gland do?
1. Increases the release of calcium from the bone matrix
2. Increases calcium reabsorption by the kidneys
3. Increases renal production of 1,25-dihydroxyvitamin D3, which increases intestinal absorption of calcium
94
Where is calcium homeostasis regulated? (3)
1. Intestinal tract
2. Kidneys
3. Bone
95
What is 1,25-dihydroxyvitain D3 also known as?
Calcitriol
96
Calcitonin can also affect calcium homeostasis. What is it produced by and where from?
Produced by C cells of the thyroid gland
97
What does calcitonin do?
Inhibits osteoclast activity and reduces the release of calcium and phosphate from bone
98
Primary hyperparathyroidism is the third most common endocrine disorder. Who does it most commonly affect?
Postmenopausal women
99
What causes primary hyperparathyroidism?
1. A single parathyroid gland adenoma (85%)
2. 4-gland hyperplasia (10-15%)
3. Double adenomas (3-5%)
4. Parathyroid carcinoma (<1%)
100
Familial cases of hyperparathyroidism can occur, what endocrine syndromes are known to be related? (3)
1. Multiple endocrine syndromes e.g. MEN-1 or MEN-2a
2. Hyperparathyroid-jaw tumour (HPT-JT)
3. Familial isolated hyperparathyroidism (FIHPT)
101
How can hyperparathyroidism present?
In those who are symptomatic (20-30%) it is the features of hypercalcaemia 'bones, stones, abdominal groans and psychic moans'
1. Muscle weakness, proximal myopathy
2. Abdominal pain, peptic ulcer disease
3. Renal colic, haematuria
4. Neuropsychiatric manifestations - depression, confusion, dementia
5. Hypertension
6. Bone pain from osteoporosis
102
Why do people with hyperparathyroidism get osteoporosis and osteopenia?
Due to the excessive calcium resorption from the bone it leads to osteoporosis and causes the bone pain and pathological fractures
103
What is osteitis fibrous cystica?
It occurs in severe cases of hyperparathyroidism. It presents with subperiosteal resorption of the distal phalanges, tapering of distal clavicles, salt and pepper appearances of the skull and brown tumours of the long bones.
104
What does excessive renal calcium excretion lead to?
Renal calculi
105
Why can hyperparathyroidism lead to peptic ulcer disease?
Hypercalcaemia can increase gastric acid secretion leading to ulcers
106
What are the differentials for hyperparathyroidism? (6)
1. Lithium-induced hypercalcaemia
2. Malignancy
3. Thyrotoxicosis
4. Sarcoidosis
5. Paget's disease of the bone
6. Addison's disease
107
What investigations can be carried out if someone presents with hypercalcaemia?
1. Look for obvious drug causes e.g. lithium, thiazide diuretics
2. Repeat plasma albumin-adjusted calcium levels
3. Ensure renal function is normal
4. Measure PTH, with will be raised in primary HPT.
108
What will phosphate levels be like in primary hyperparathyroidism?
Low - hypophosphataemia
109
What is the treatment for mild, asymptomatic hyperparathyroidism? (6)
1. Surveillance can be used in patients with mildly elevated calcium levels and close to normal renal and bone status
2. Check serum creatinine level and calcium levels every 6 months
3. 3 site DEXA study every 1-2 years
4. Avoid dehydration
5. Avoid thiazide like diuretics
6. There is no recommendation to limit calcium intake
110
What is the only potential cure for hyperparathyroidism?
Surgery - parathyroid surgery to remove abnormal parathyroid gland(s) is suggested in most sympathetic patients.
111
What are the guidelines for the surgical management of PHPT?
1. Age under 50
2. Serum albumin-adjusted calcium is more than 0.25mmol/L above the upper limit of normal
3. Creatnine clearance <60ml/minute
4. Renal calculi
5. DEXA -2.5
6. Vertebral fractures
7. Patient request
112
What do they do during surgery to determine if the abnormal gland has been removed?
Intraoperative PTH is measured, PTH levels drop by 50% within 10-15 minutes of the hyper-functioning parathyroid tissue being removed
113
If people don't meet the criteria for surgical treatment of PHPT, or they don't want surgery, what is the medical management? (3)
Treatment is aimed at improving bone density and achieving calcium homeostasis.
1. HRT and raloxifene may be used in postmenopausal women. They have been shown to reduced calcium levels as well as improve bone density.
2. Bisphosphonates (particularly alendronate)
3. Cinacalcet reduces both serum calcium and PTH levels and raises serum phosphate. Cinacalcet does not, however, reduced bone turnover or improve bone mineral density
114
What are the complications of PHPT surgery? (3)
1. Hypocalcaemia due to 'hungry bone syndrome' - until the normal parathyroid glands regain sensitivity, there will be a hypoparathyroidism. Calcium and vitamin D supplements may be required.
2. Recurrent laryngeal nerve injury - if a patient develops new hoarseness postoperatively. Immediate laryngoscopy is required.
3. Haematoma formation - if this occurs in the pre-tracheal space, urgent evacuation is required before airway obstruction occurs.
115
What are the causes of secondary hyperparathyroidism?
CKD - the parathyroid gland becomes hyper plastic after long-term stimulation in response to chronic hypocalcaemia
116
Who is most likely to develop SHPT?
People with stage 5 CKD - those on dialysis (almost all patients on dialysis have SHPT)
117
In addition to people with CKD, who else can develop SHPT?
Potentially anyone with chronic hypocalcaemia - e.g. vitamin D deficiency or malabsorption
118
What are the findings for someone with SHPT?
1. Low/normal calcium
2. Raised PTH
3. Phosphate levels depend on aetiology - high in renal disease, low in vitamin D deficiency
119
What is the treatment for SHPT?
Medical management is the mainstay of treatment and treating the underlying condition for example correcting vitamin D deficiency.
Treatments include:
1. Calcium supplementation
2. Correction of vitamin D
3. Phosphate restriction or phosphate binders
4. Vitamin D analogues
5. Calcimimetics e.g. cinacalcet (though NICE only recommends the use of this in people who have end-stage kidney disease)
120
What causes tertiary HPT?
Prolonged SHPT - the glands become autonomous, producing excessive PTH even after the cause of hypocalcaemia has been corrected, resulting in hypercalcaemia. CKD is the most common cause.
121
What are the findings on investigations of THPT?
1. Raised calcium
2. Raised PTH
3. Raised phosphate
122
What is the recommended treatment for THPT?
Total or subtotal parathyroidectomy
123
What does hyperlipidaemia refer to?
It is a term used to denote raised serum levels of one or more of total cholesterol, low-density lipoprotein cholesterol, and/or triglycerides.
124
Hyperlipidaemia is one of the three modifiable risk factors for CVD, what are the other two?
1. Smoking
| 2. Hypertension
125
Approximately what % of the UK population has a serum cholesterol level greater than 5.2mmol/L?
66%
126
What are the inherited disorders that cause hyperlipidaemia/hypercholesterolaemia?
1. Familial dyslipidaemias
2. Familial hypercholesterolaeima
3. Familial combined hyperlipidaemia
4. Apoprotein disorders
127
What are the secondary causes of hyperlipidaemia? (5)
1. Medical conditions e.g. hypothyroidism, obstructive jaundice, Cushing's syndrome, anorexia, nephrotic syndrome, diabetes and CKD
2. Drugs e.g. thiazide-like diuretics, ciclosporin, beta-blockers, COCP
3. Pregnancy
4. Obesity
5. Alcohol abuse
128
What two measurements can be done to achieve the best estimate for CVD risk?
1. Total cholesterol
| 2. HDL-C
129
Before starting someone on lipid modification therapy for primary prevention of CVD, what lipid samples need to be take first?
1. T-chol
2. HDL-C
3. non-HDL-C
4. TG concentrations
130
When should the possibility of familial hypercholesterolaemia be considered in someone with raised cholesterol?
If total cholesterol is more than 7.5mmol/L and there is family history of premature CHD
131
What pattern of inheritance is familial hypercholesterolaemia?
Autosomal dominant
132
How many people in the UK have familial hypercholesterolaemia?
Between 1 in 250 and 1 in 500 - so approximately 130,000-260,000-
133
What % risk coronary heart disease is there for men and women respectively with heterozygous familial hypercholesterolaemia?
50% in men by age 50 and 30% in women by age 60
134
At what total cholesterol level should specialist assessment be arranged?
TChol >9.0mmol/L or a non-HDL-C concentration of >7.5mmol/L (even in the absence of a first degree relative with premature CHD)
135
Although the diagnosis for familial hypercholesterolaemia is primarily biochemical, what two physical signs may be evident in patients?
1. Premature arcus senilis - a white or gray opaque ring in the corneal margin
2. Tendon xanthomata - hard, non-tender nodular enlargement of tendons. They are most commonly found on the knuckles and the Achilles tendon.
136
What criteria is used to diagnose familial hypercholesterolaemia?
Simon Broom diagnostic criteria
137
What is included in the Simon Broom criteria?
1. A TChol level in an adult of >7.5mmol/L
AND
2. Tendon xanthomata or evidence of these signs in a first degree/second degree relative
OR
3. DNA evidence of an LDL receptor mutation, familial defective apo-B-100 or PCSK9 mutation
138
What is the most common genetic dyslipidaemia, occurring in how many people?
Familial combined hyperlipidaemia occurring in 1 in 100 people
139
When is familial combined hyerplipidaemia suspected? (2)
1. There is a family history of hyperlipidaemia or premature CHD not due to familial hypercholesterolaemia
2. Moderate-to-severe mixed hyperlipidaemia (typically TChol 6.5-8.0 mmol/L and TG 2.3-5.0 mmol/L)
140
What investigations need to be carried out in suspected familial mixed hyperlipidaemia? (5)
1. Lipid profile
2. Fasting blood glucose (to exclude hyperlipidaemia secondary to diabetes)
3. Renal function (to exclude CKD)
4. LFTs - transaminases to rule out liver disease in the event of a statin having to be initiated - though a statin can still be initiated unless the levels are greater than three times the upper limit of normal
5. TSH - to exclude myxoedema
141
How is hypercalcaemia diagnosed?
If the serum calcium concentration is higher than 2.6mmol/L on two occasions following adjustment (correction) for the serum albumin concentrations.
142
What are the causes of hypercalcaemia? (8)
1. Hyperparathyroidism
2. Malignancy
3. Drugs
4. Granulomatous diseases
5. Renal
6. Familial hypocalciuric hypercalcaemia
7. Non-parathyroid endocrine diseases
8. Immobility
143
What are the mechanisms of hypercalcaemia in malignancy? (2)
1. In 80% the mechanism is secretion of parathyroid hormone-related protein and other circulating factors by the tumour (a paraneoplastic syndrome)
2. In 20% bone metastases cause osteolysis and release skeletal calcium, for example in breast cancer and multiple myeloma
144
What are the drugs that can cause hypercalcaemia? (4)
1. Thiazide diuretics - caused by reduced urinary excretion
2. Lithium - lithium may directly stimulate PTH secretion and increase renal calcium reabsorption
3. Vitamin D
4. Vitamin A
145
What are the granulomatous diseases that can lead to hypercalcaemia?
1. Sarcoidosis
2. TB
3. Leprosy
4. Candidiasis
5. and tons other random ones
- mechanism is thought to be ectopic production of calcitriol by cells in the lungs and lymph nodes
146
What is the renal disease cause of hypercalcaemia?
In CKD, low calcium levels cause parathyroid gland hypertrophy
147
What are the non-parathyroid endocrine disease?
1. Thyrotoxicosis
2. Addison's disease
3. Phaeochromocytoma
4. Vasoactive intestinal polypeptide hormone-producing tumour
148
What are the skeletal symptoms/signs related to hypercalcaemia? (4)
1. Bone pain
2. Skeletal deformities
3. Osteoporosis
4. Fractures
149
What are the neuropsychiatric signs/symptoms of hypercalcaemia? (4)
1. Drowsiness, delirium, coma
2. Fatigue, lethargy, muscle weakness, insomnia
3. Impaired concentration and memory loss
4. Depression, anxiety, irritability, psychosis
150
What are the gastrointestinal signs/symptoms of hypercalcaemia? (3)
1. Nausea, vomiting, anorexia, weight loss
2. Constipation, abdominal pain
3. Peptic ulcer, pancreatitis
151
What are the renal signs/symptoms of hypercalcaemia? (3)
1. Renal colic due to renal stones
2. Thirst, polyuria, polydipsia, nocturia and dehydration
3. Renal impairment due to obstructive uropathy
152
What are the cardiovascular sign/symptoms of hypercalcaemia? (3)
1. Hypertension
2. Shortened QT interval, prolonged PR interval
3. Cardiac arrhythmias such as VF
153
What is the management of someone who is found to have severe hypercalcaemia or severe symptoms?
Arrange emergency hospital admission
154
What is a phaeochromocytoma?
It is a rare tumour that secretes catecholamines. It is derived from chromaffin cells, usually in the adrenal medulla, however occasionally extra-adrenal phaeochromocytomas or paraglangliomas occur.
155
What is the other name for a phaeochromocytoma if it is located not in the adrenal medulla?
A paraganglioma
156
What can the excessive production of catecholamines from the phaeochromocytoma cause? (2)
1. Life-threatening hypertension
| 2. Cardiac arrhythmias
157
What are the gene mutations known to be associated with phaeochromocytomas 1/3 of the time? (4)
They are from germline mutations in:
1. MEN 2
2. Von Hippel-Lindau disease
3. Neurofibromatosis type 1
4. Paraganglioma syndromes type 1, 3 and 4
158
What does phaeochromocytoma mean?
Greek Phios means dusky, chroma means colour and cytoma means tumour. It refers to the colour of the tumour cells when stained with chromium salts.
159
What are phaeochromocytomas known to produce? (3)
1. Noradrenaline
2. Adrenaline
3. Dopamine
160
What do the familial phaeochromocytomas (PHOCC) produce more often?
Noradrenaline
161
What do the sporadic phaeochromo's produce most often?
Adrenaline
162
What % of phaeochromo's are malignant?
10-15%
163
What % of phaeochromo's are familial?
20%
164
Which familial syndromes can phaeochromos present in? (3)
1. MEN syndrome
2. Neurofibromatosis
3. Von Hippel-Lindau disease
165
In which syndrome can phaeochromos occur bilaterally?
70% of them in people with MEN syndromes
166
Why can symptoms of phaeochromo's vary in duration and severity?
Because they may secrete constantly or intermittently
167
What are the symptoms associated with phaeochromo's? (12 - the first 4 are most common)
1. Headache
2. Profuse sweating
3. Palpitations
4. Tremor
5. Nausea
6. Weakness
7. Anxiety
8. Sense of doom
9. Epigastric pain
10. Flank pain
11. Constipation
12. Weight loss
168
If a person with a phaeochromo also has neurofibromas, what may be seen on examination?
Cafe au lait patches
169
What may be found on blood tests when suspecting phaeochromo's?
1. Blood glucose is often raised
2. Calcium may be elevated
3. Haemoglobin is elevated due to haemoconcentration from reduction in circulating volume
4. Plasma catecholamines and plasma metanephrines have both been used in diagnosis.
170
Which blood test is the first line for diagnosing phaeochromo's?
Plasma free metanephrines
171
Which drugs may interfere when testing for phaeochromos and why? (6)
Drugs that elevate metanephrines e.g.
1. Tricyclic antidepressants
2. Alcohol
3. Levadopa
4. Labetalol
5. Sotalol
6. Benzodiazepines
172
Where as the common locations for extra-adrenal phaeochromo's? (5)
1. Close to the origin of the inferior mesenteric artery
2. Bladder wall
3. Heart
4. Mediastinum
5. Carotid and glomus jugulare tumours
173
Which imaging technique is gold standard for diagnosing phaeochromo?
CT scan
174
What are the risk factors for precipitating a hypertensive crisis in someone with a phaeochromo? (6)
1. Induction of anaesthesia
2. Opiates
3. Dopamine antagonists
4. Decongestants such as pseudoephedrine
5. X-ray contrast media
6. Childbirth
175
What is the management of phaeochromocytomas?
Surgical resection
176
What medical management needs to be done before surgical resection of phaeochromo's?
Alpha and beta blockers given to control blood pressure and prevent intra-operative hypertensive crisis
1. Alpha blockers are started at least 7 days before the operation to allow for expansion of blood volume
2. Beta blockers are then started only after alpha blockers have been started
3. CCBs are also useful
177
What is tested after surgical resection of phaeochromo's to confirm the surgery has worked?
2 weeks after surgery a 24-hour urine collection for total catecholamines, metanephrines and VMA is done and is results are normal, the prognosis is excellent.
178
When is a phaeochromo most likely to be malignant?
If it has arisen in childhood
179
What is Cushing's syndrome and what is it caused by?
It is caused by prolonged exposure to elevated levels of either endogenous or exogenous glucocorticoids AKA the body is producing too much cortisol
180
What are the two groups Cushing's syndrome can be divided into? (2)
1. ACTH-dependent disease; excessive ACTH from the pituitary (Cushing's disease), ectopic ACTH-producing tumours
2. Non-ACTH-dependent; adrenal adenomas, adrenal carcinomas, excess glucocorticoid administration
181
Who is more likely to get Cushing's syndrome? (4)
People with:
1. Diabetes
2. Obesity
3. Hypertension
4. Osteoporosis
182
What is the most common cause of Cushing's syndrome?
Exogenous glucocorticoids
183
For the endogenous causes of Cushing's syndrome, which one isomer common - corticotropin-dependent or corticotropin-independent?
Corticotropin-dependent - accounting for 80-85% of cases
184
What % of corticotropin-dependent causes are due to Cushing's disease?
80%
185
If cushing's disease accounts for 80% of corticotrophin-dependent causes of Cushing's syndrome, what causes the remaining 20%?
Ectopic corticotropin syndrome - usually due to small-cell lung carcinoma and bronchial carcinoid tumours (though others including phaeochromocytoma, pancreatic neuroendocrine tumours, medullary thyroid cancers etc. can also be a cause)
186
What are the causes of corticotropin-independent Cushing's syndrome?
Often due to unilateral tumours - adrenal adenoma (60%) or adrenal carcinoma (40%). There are other rarer causes for example McCune-Albright syndrome.
187
What are the clinical features of Cushing's syndrome/how can it present? (14) ...fun
1. Truncal obesity
2. Facial fullness/moon face/facial plethora
3. Proximal muscle wasting/weakness
4. Diabetes/impaired glucose tolerance
5. Reduced libido
6. Hypertension
7. Nephrolithiasis
8. Skin atrophy, hirsutism, acne
9. Depression, cognitive dysfunction
10. Osteoporosis
11. Oedema
12. Thirst, polydipsia, polyuria
13. Impaired immune function - increase infections
14. Growth restriction in children
188
What are the differential diagnoses for Cushing's syndrome? (5)
1. Chronic severe anxiety/depression
2. Obesity
3. Chronic excess alcohol consumption - Cushingoid appearance
4. Poorly controlled diabetes
5. HIV infection
189
What are the recommended diagnostic tests for the presence of Cushing's syndrome? (3)
1. 24-hour urinary free cortisol
2. 1mg overnight dexamethasone suppression test
3. Late-night salivary cortisol
190
What is involved in the 24-hour urinary free cortisol collection for diagnosis of Cushing's syndrome? (3)
1. Ideally three collections, measuring creatinine excretion at the same time
2. Cushing's syndrome can be confidently diagnosed if two or more collections measure cortisol excretion as ore than three times the upper limit for normal
3. The test needs to be repeated if creatinine excretion varies by more than 10% between collections
191
When may false positives occur when doing the 24-hour urinary free cortisol collection? (6)
1. Anorexia
2. Pregnancy
3. Exercise
4. Psychoses
5. Alcohol/withdrawal
6. Illness
192
What is the definitive management of endogenous Cushing's syndrome?
Tumour resection
193
If surgical resection is not possible, what is the medical management of endogenous Cushing's syndrome?
1. Metyrapone
2. Ketoconazole
3. Mitotane
(first two short acting, third one is long-acting)
194
What are the complications of Cushing's syndrome? (9)
1. Metabolic syndrome
2. Hypertension
3. Impaired glucose tolerance and diabetes
4. Obesity
5. Hyperlipidaemia - raised LDL
6. Coagulopathy - thrombophilia
7. Osteoporosis
8. Impaired immunity
9. Nelson's syndrome
195
What are the causes of premature death in untreated Cushing's syndrome? (3)
1. Vascular disease - MI/stroke
2. Uncontrolled diabetes/complications of diabetes
3. Infections
196
How does cortisol regulate the action of insulin?
Cortisol makes fat and muscle cells resistant to the action of insulin, and enhances the production of glucose by the liver.
197
What is Cushing's disease?
It is when you have a pituitary adenoma or other problem in the pituitary gland leading to Cushing's syndrome
198
Which HLA types are associated with type 1 diabetes?
DR3 and DR4
199
Which antibody is associated with type 1 diabetes?
Islet cell
200
What are the risk factors for T2DM? (9)
1. Obesity (especially central)
2. Lack of physical activity
3. Ethnicity
4. History of gestational diabetes
5. Impaired glucose tolerance
6. Impaired fasting glucose
7. Drug therapy - thiazide diuretic with a beta blocker
8. Low fibre, high-glycemic index diet
9. Metabolic syndrome
201
What programme is offered to patients recently diagnosed with diabetes?
DESMOND - diabetes education and self management for ongoing and newly diagnosed
202
If metformin is not adequate, or is contraindicated, what are the other options to treat type 2 diabetes?
1. DPP-4 inhibitor e.g. sitagliptin
2. Pioglitazone
3. Sulfonylurea
203
What would be the expected TFTs for a person with thyrotoxicosis e.g. Graves' disease?
TSH: low
T4: high
204
What would be the expected TFTs for someone with primary hypothyroidism?
TSH: high
T4: low
205
What would be the expected TFTs for someone with secondary hypothyroidism?
TSH: low
T4: low
206
What would be the expected TFTs for someone with subclinical hypothyroidism?
TSH: high
T4: normal
207
What would be the expected TFTs for someone with poor compliance with thyroxine?
TSH: high
T4: normal
208
What is the expected TFTs for someone on steroid therapy?
TSH: low
T4: normal
209
In sick euthyroid syndrome, which TFT is particularly low?
T3
210
What is hypoparathyroidism characterised by?
1. Hypocalcaemia
2. Hyperphosphataemia
3. Low or inappropriately normal levels of parathyroid hormone (PTH)
211
Why does hypoparathyroidism lead to high phosphate levels?
Because phosphate reabsorption from the kidney is reduced by the parathyroid hormone. If the PTH levels are low, serum phosphate will rise (more will be reabsorbed)
212
What is the most common cause of hypoparathyroidism?
Iatrogenic - following anterior neck surgery
213
What is transient hypoparathyroidism in neonates?
In healthy term neonates, a reduction in serum calcium levels happen by 24-48 hours of age. If neonates are high risk for example infants of mothers with diabetes or hyperparathyroidism, or preterm, they may develop hypocalcaemia, requiring at least 72 hours of calcium supplementation.
214
Which congenital/genetically inherited syndrome is associated with a defect parathyroid gland?
DiGeorge syndrome - abnormal development of the parathyroid glands.
215
What are the two autoimmune conditions that hypoparathyroidism can present in?
1. Autoimmune polyglandular syndrome type 1 (APS-1): features include hypoparathyroidism, adrenal insufficiency and chronic candidiasis
2. Autoimmune polyglandular syndrome type 2 (APS-2): adrenal insufficiency, insulin-dependent diabetes and thyroid disease.
216
What are the two genetic syndromes (other than DiGeorge) that include hypoparathyroidism?
1. Hypoparathyroidism, deafness and renal dysplasia (HDR) syndrome
2. Hypoparathyroidism, retardation and dysmorphism (HRD) syndrome
217
What are the causes of acquired hypoparathyroidism? (5) good luck with them
1. Neck surgery (thyroid, parathyroid, laryngeal etc)
2. Radiation or drugs
3. Infiltration of the parathyroid glands - destruction due to iron deposition or copper deposition e.g. Wilson's disease
4. Magnesium deficiency - which can occur in chronic alcoholism, burns and hereditary renal or intestinal hypomagnesaemia.
5. Magnesium excess (when it is used to treat preterm labour/pre-eclampsia)
218
How can hypoparathyroidism present? ...what are the symptoms of hypocalcaemia? (15.....15 of them!)
1. Muscle pains
2. Bone pain
3. Abdominal pain
4. Paraesthesiae
5. Facial twitching
6. Stridor
7. Convulsions - usually grand mal
8. Syncope
9. Memory impairment
10. Lethargy
11. Anxiety and depression
12. Confusion
13. Headaches
14. Brittle nails, dry hair and skin
15. Painful menstruation
219
If considering hypoparathyroidism as a differential, what important points should be elicited in the history? (2)
1. History of previous neck surgery
| 2. Family history of any hypoparathyroid disorders
220
What is Chvostek's sign?
Tapping of the fifth facial nerve in front of the ear with the patients mouth slightly open causes contraction of the facial muscles
221
What is Trousseau's sign?
Occlude the arterial circulation of the forearm using a blood pressure cuff inflated to the systolic blood pressure for three minutes. Carpopedal spasm is induced.
222
What investigations - bloods - need to be done when suspecting hypoparathyroidism?
1. Calcium (low)
2. Phosphate (high)
3. PTH (low)
4. Alkaline phosphatase (normal)
223
If there is pseudohypoparathyroidism , what would the blood picture show?
Low calcium but high or normal PTH
224
What is the management/treatment for hypoparathyroidism?
1. If severe hypocalcaemia - IV calcium
2. A diet rich in diary products containing calcium and vitamin D is recommended
3. Basis of treatment = calcium and vitamin D
225
What is the most common malignancy of the endocrine system?
Thyroid cancer
226
Which types of thyroid cancer are highly treatable and usually curable?
The differentiated tumours - papillary or follicular
227
Which are the undifferentiated thyroid tumours?
Medullary and anaplastic - they are less common of the thyroid cancers but are aggressive and metastasise early
228
What is the most common form of thyroid cancer, accounting for 70% of cases?
Papillary thyroid carcinoma
229
What is the peak age range of onset of papillary thyroid cancer and which sex is it more common in?
Age 35-40 years and three times more common in women
230
What is the second most common form of thyroid cancer, accounting for 10% of them?
Follicular thyroid cancer
231
At what age range do follicular thyroid cancers tend to present and what is it associated with?
30-60 years of age, and tend to occur in areas of low iodine (it has a greater propensity to metastasise to the lung and bones than papillary carcinoma)
232
Where do medullary thyroid cancers arise from?
Parafollicular calcitonin-producing C cells of the thyroid - accounting for 5-8% of all thyroid malignancies
233
Which type of thyroid/blood cancer is associated with Hasimoto's thyroiditis?
Thyroid lymphomas (almost always non-Hodgkin's)
234
What are the risk factors for thyroid cancer? (5)
1. Exposure to ionising radiation (increased incidence of thyroid cancer in children and adolescents in areas close to the Chernobyl incident)
2. History of goitre, thyroid nodules or thyroiditis, +ve FHx, female gender and asian race
3. Genetics
4. Familial adenomatous polyposis
5. Obesity
235
What are the red flag features associated with thyroid cancer? (7)
1. A family history of thyroid cancer
2. History of previous irradiation
3. A child with a thyroid nodule
4. Unexplained hoarseness or stridor with a goitre
5. A painless thyroid mass enlarging rapidly
6. Palpable cervical lymphadenopathy
7. Insidious or persistent pain lasting for several weeks
236
Apart from clinical features, how else can you differentiate between type 1 and type 2 diabetes?
Presence of autoantibodies - islet cell antibodies (ICA) and anti-glutamic acid decarboxylase (GAD) antibodies
237
For treatment of type 2 diabetes, what are people normally started on first?
Metformin
238
What does metformin do, and what are its side effects?
It increases insulin sensitivity in the body and helps with weight loss.
It's side effects include nausea, diarrhoea and abdominal pain.
239
Why should metformin be avoided if someone has an eGFR are <36?
They are at risk of lactic acidosis (must also be stopped if tissue hypoxia e.g. sepsis or MI)
240
When should another treatment be added after metformin for people with type 2 diabetes?
If their HbA1c >53mmol/L 16 weeks after starting metformin
241
What is step 2 in the treatment for type 2 diabetes (after metformin)
Sulfonylurea e.g. gliclazide 40mg/d
242
For someone with diabetic retinopathy - background (stage 1), what is seen? (2)
1. Dot and blot (micro aneurysms and haemorrhages)
| 2. Hard exudates
243
What is seen in pre-proliferative retinopathy?
1. Cotton-wool spots
| 2. Haemorrhages
244
What is seen in proliferative retinopathy?
Neovascularisation
245
What is seen in maculopathy?
Suspect if decreased visual acuity
246
Which electrolyte disturbance is most commonly associated with diabetes insipidus?
Hypernatraemia
247
What are the causes of hypernatraemia? (3)
1. Diabetes insipidus
2. Dehydration
3. Hyperosmolar non-ketotic diabetic coma (HHS)
248
What are the causes of hyponatraemia? (10)
1. SIADH
2. Thiazides
3. Addisons
4. Vomiting
5. Heart failure
6. Hypothyroidism
7. Burns
8. Diarrhoea
9. Liver cirrhosis
10. Psychogenic polydipsia
249
Which hormone is secreted in carcinoid sydnrome?
Serotonin
250
Carcinoid syndrome typically occurs when there are metastases where?
Liver metastasis
251
What are the features of carcinoid syndrome? (7)
1. Flushing
2. Diarrhoea
3. Bronchospasm
4. Hypotension
5. Right heart valvular stenosis
6. Production of ACTH and GHRH - resulting in Cushing's syndrome
7. Pellagra
252
What are the investigations for carcinoid syndrome? (2)
1. Urinary 5-HIAA
| 2. Plasma chromogranin A y
253
What is diabetes insipidus (DI)?
It is a condition caused by hyposecretion of, or insensitivity to the effects of, ADH (AKA arginine vasopressin AVP). Its deficiency or failure to act, causes an inability concentrate urine in the distal renal tubules, leading to the passage of copious volumes of dilute urine.
254
How much urine does a person with diabetes insipidus pass in 24 hours?
>3 litres per 24 hours of low osmolality urine
255
What are the two major forms of DI?
1. Cranial DI
| 2. Nephrogenic DI
256
What happens in cranial DI?
There is decreased secretion of ADH. This reduces the ability to concentrate urine so causes polyuria and polydipsia.
257
What happens in nephrogenic DI?
Decreased ability to concentrate urine because of resistance to ADH in the kidneys
258
In addition to the two main forms of DI, what are the two rarer forms?
1. Gestational DI
| 2. Primary polydipsia - caused by primary defect in osmoregulation of thirst
259
Nephrogenic DI occurs most commonly as a result of what?
Adverse effect of lithium - occurs in up to 40% of patients taking lithium
260
What is the most common cause of cranial DI?
This is usually due to disease of the hypothalamus or surrounding tissues. Posterior pituitary disease tends not to cause DI, as secretion continues in the hypothalamus, unless a pituitary tumour extends above into the sella, putting pressure on the hypothalamus,
261
What are the causes of acquired cranial DI? - as in what causes disease of the hypothalamus or surrounding tissues? (8)
1. Idiopathic
2. Tumours - craniopharyngioma, germinoma
3. Intracranial surgery
4. Head injury
5. Granulomata
6. Infections - encephalitis, meningitis, cerebral abscess
7. Vascular disorders - haemorrhage/thrombosis
8. Post-radiotherapy
262
What are the inherited causes of cranial DI? (2)
1. Autosomal recessive compilation of DI, diabetes, optic atrophy, deafness (DIDMOAD) - known as Wolfram's syndrome
2. Autosomal dominant mutations of vasopressin gene
263
What are the acquired causes of nephrogenic DI? (7)
1. Idiopathic
2. Hypokalaemia
3. Hypercalcaemia
4. CKD
5. Drugs - lithium, orlistat
6. Renal tubular disease - sickle cell, pyelonephritis
7. Pregnancy
264
What are the congenital causes of nephrogenic DI? (2) (good luck with that)
1. X-linked mutation in V2 ADH-receptor gene
| 2. Autosomal recessive defect in aquaporin 2
265
What are the symptoms of diabetes insipidus and how can they present? (4)
The onset of symptoms can be vague and insidious.
1. Marked polyuria (>3 litres a day)
2. Polydipsia and chronic thirst
3. Nocturia (children may develop nocturnal enuresis where they have previously been continent)
4. Infants present with irritability, failure to thrive, protracted crying, fever, anorexia
266
What are the signs of DI?
1. Dehydration
2. Bladder grossly enlarged
3. 24-hour urinary collection will show volume >3 litres
267
What are the differentials for DI?
1. Diabetes
2. Psychogenic or primary polydipsia
3. Cushing's syndrome
4. Hyperkalaemia
268
What investigations are done for someone with suspected DI? (5)
1. Biochemistry - plasma glucose, U&Es, urine specific gravity
2. 24-hour urine collection
3. Fluid deprivation test with response to desmopressin
4. MRI of the pituitary, hypothalamus and surrounding tissues
5. Renal tract USS may be used to assess for obstructive complications caused by the high urinary back-pressure
269
How does the fluid deprivation test work for investigating DI?
The patient is deprived of fluids for up to 8 hours or 5% loss of body weight, following which desmopressin 2mcg IM is given.
270
What would you expect to see after doing the fluid restriction and desmopressin test in someone with cranial DI?
The urine would be even more concentrated as the desmopressin acts in a similar way to ADH if it was released, and would retain fluid in the body
271
What would you expect to see after doing the fluid restriction and desmopressin test in someone with nephrogenic DI?
The urine would remain less concentrated - all fluid would still be lost as the problem is in the kidneys, not how much ADH or desmopressin is given.
272
The fluid restriction and desmopressin test is based on urine osmolality before and after the desmopressin. It is about how concentrated the urine is. What would be expected with a primary/psychogenic polydipsia?
Very concentrated urine after fluid restriction and desmopressin - as there is no cranial or nephrogenic reason as to why the ADH and desmopressin would not work
273
What is the management for cranial DI?
1. As the primary problem is a hormone deficiency - physiological replacement with desmopressin is usually effective. This ca be given orally, intranasally or parenterally.
2. Mild cases of DI (urine output 3-4 litres in 24 hours) can be managed by ingestion of water to quench thirst
3. It is essential to avoid chronic overdosage of desmopressin
274
Why is it essential to avoid chronic overdosage with desmopressin?
It will cause hyponatraemia
275
What is sometimes recommended to try and avoid the development of hyponatraemia in people taking desmopressin for cranial DI?
Miss one desmopressin treatment each week
276
What is the treatment for nephrogenic DI?
1. If daily urine volume is <4litres/24 hours and the patient does not have severe dehydration, then definitive therapy is not always necessary. It is important for patients to have access to drinking water and enough to satiate their thirst
2. Stop any drugs that are causing the problem
3. Dietary advice to eat less protein and salt
4. Patients with severe nephrogenic DI, may be prescribed a combination of thiazide like diuretics and NSAIDs
277
What are the side effects of desmopressin? (5)
1. Headache
2. Stomach pain
3. Feeling sick
4. Blocked or runny nose
5. Nosebleeds
278
What are the symptoms of hyponatraemia? (3)
1. Severe or prolonged headache
2. Confusion
3. Nausea and vomiting
279
Which two drugs are commonly known to cause nephrogenic DI? (2)
1. Lithium
| 2. Tetracycline
280
Why are thiazide like diuretics and NSAIDs prescribed in nephrogenic DI?
Thiazide diuretics can reduce the rate the kidneys filter the blood, which reduces the amount of urine passed from the body over time, and NSAIDs help reduce urine volume further.
281
What do they mean by high plasma osmolality and low urine osmolality in DI?
High plasma osmolality means high levels of salt in the plasma and low urine osmolality means low levels of salt
282
What is the test for Wilsons disease called?
Caeruloplasmin
283
If someone has hereditary haemochromatosis, what type of DI are they are risk of developing?
Cranial
284
So for DI to be diagnosed, what must the urine osmolality be? (high or low)?
Low
285
Why does the action of thiazides releasing sodium into the urine help break the polyuria-polydipsia cycle?
Because DI leads to hypernatraemia so people drink lots of water, but if you lose the salt, you won't drink as much water . sorted.
286
What is Wolfram's syndrome?
```
DIDMOAD
DI
DM
Optic atrophy
Deafness
```
287
What are carcinoid tumours?
Carcinoid tumours are rare, slow-growing tumours that originate in cells of the diffuse neuroendocrine system. They occur most frequently in tissues derived from the embryonic gut.
288
How can the carcinoid tumours be classified in terms of locations?
As they are derived from the embryonic gut - they are divided into the:
- Foregut (25%)
- Midgut (50%)
- Hindgut (15%)
289
What do carcinoid tumours secrete?
Various bioactive compounds including:
1. Serotonin
2. Bradykinin
...leading to carcinoid syndrome
290
What are the features of carcinoid syndrome?
1. Bronchospasm
2. Diarrhoea
3. Skin flushing
4. Right-sided valvular heart lesions (tricuspid and pulmonary valve stuff)
291
Which carcinoid tumours are most likely to cause carcinoid syndrome?
Carcinoid tumours in the ileum and jejunum - especially if they are larger than 1cm
