Endo3

Question 1

What is secreted when there is a calcium deficiency?

Answer 1

PTH

Question 2

What organs does PTH directly and indirectly act upon?

Answer 2

Bones (directly)
Kidneys (directly)
SI (indirectly)

Question 3

How does PTH act on the bones?

Answer 3

Increases osteoclast activity
Induces bonre resportion
Plasma Ca concentration increases

Question 4

How does PTH act on the kidneys?

Answer 4

Increases Ca resorption and PO4 excretion

Increases 1 alpha hydroxylase activity

Question 5

How does PTH act on the SI?

Answer 5

Increases 1 alpha hydroxylase activity in the kidneys
Converts 25-OH D3 into 1,25-(OH)2 D3 aka calcitriol
Calcitriol acts upon the SI
increases Ca resorption and PO4 resorption

Question 6

What is the pathway of vitamin D?

Answer 6

Vitamin D is converted to 5-OH D3 in the liver
5-OH D3 is converted into 1,25-(OH)2 D3 in the kidneys
1,25-(OH)2 D3 increases Ca and PO4 resorption

Question 7

What are some causes of hypercalcaemia?

Answer 7

Endocrine:
-1 hyperPTH, 3 hyperPTH (renal failure)
Malignancy:
-PTHrp from SSC/breast Ca
High bone turnover:
-Paget's, MM, hyperthyroidism
Other:
-MEN 1/2a, sarcoidosis

Question 8

What are some causes of hypocalcaemia?

Answer 8

Endocrine:
-Vit D3 deficiency, hypoPTH
Electrolyte:
-Hyperphosphataemia, hypomagnesaemia
Other:
-Acute renal failure, pancreatitis, iatrogenic, drugs (eg. lithium)

Question 9

What is the normal range of serum calcium?

Answer 9

2.2-2.6mmol/L

Question 10

What are the signs and symptoms of hypercalcaemia?

Answer 10

Stones
-polyuria, thirst, nephrocalcinosis, renal colic, chronic renal failure
Bones
-bony pain
Abdominal groans
-anorexia, nausea, dyspepsia, pancreatitis
Psychic moans
-fatigue, depression, impaired consciousness, coma (if >3)

Question 11

What are the signs and symptoms of hypocalcaemia?

Answer 11

CATs go numb:
Convulsions
Arrhythmia
Tetany
Paraesthesia

Trousseau’s sign
Chvostek’s sign

Question 12

What is Trousseau’s sign?

Answer 12

Carpopedal spasm
Triggers due to ishaemia
eg. applying a BP cuff

Question 13

What is Chvostek’s sign?

Answer 13

Twitch of the face

Triggered by tapping a facial nerve

Question 14

What are the investigations for hyper/hypocalcaemia?

Answer 14

Plasma Ca
Plasma Vit D3
Plasma PTH
Plasma PO4
ALP
Radiology
ECG
Bone biopsy

Question 15

What is the treatment for hypercalcaemia?

Answer 15

Fluids
IV bisphosphonates
Haemodialysis
Treat underlying cause eg surgery for Ca

Question 16

What is the treatment for hypocalcaemia?

Answer 16

IV calcium gluconate 10%
Calcium chloride
Vit D/Ca supplements
Treat underlying cause

Question 17

What is primary hyperparathyroidism?

Answer 17

Abnormal secretion of PTH

Question 18

What is secondary hyperparathyroidism?

Answer 18

Abnormal secretion of PTH secondary to hypocalcaemia

Question 19

What is tertiary hyperparathyroidism?

Answer 19

PTH secretion due to long term 2 hyperPTH

Question 20

What are the common causes of 1 hyperPTH?

Answer 20

Adenoma
Parathyroid carcinoma
MEN, radiation

Question 21

What are the common causes of 2 hyperPTH?

Answer 21

Chronic renal failure

Vit D3 deficiency

Question 22

What are the common causes of 3 hyperPTH?

Answer 22

Chronic renal failure

Question 23

What are the symptoms of hyperPTH?

Answer 23

Insidious onset
Many are asymptomatic
Features of hypercalcaemia

Question 24

What are the investigations for hyperPTH?

Answer 24

U+E:

• Ca raised in 1+3, normal/low in 2
• ALP slightly raised
• Vit D low in 2
• PTH raised
• PO4 low in 1+3, high in 2

Question 25

What is the treatment for hyperPTH?

Answer 25

``` Treat acute hypercalcaemia with fluids Surgical is definitive treatment If surgery is contraindicated: -bisphosphonates -oestrogen -cinacalcet (PTH carcinoma, 3 hyperPTH) ```

Question 26

What are the complications of hyperPTH?

Answer 26

``` Inflammation Organ deposition Arrhythmia Death Osteitis fibrosa cystica Surgical complications ```

Question 27

What is osteomalacia?

Answer 27

Vit D deficiency leading to a disorder of bone matrix mineralisation in adults

Question 28

What is Ricket's?

Answer 28

Vi D deficiency leading to a disorder of bone matrix mineralisation in children

Question 29

What are the risk factors for Vit D def?

Answer 29

``` Dietary Lack of sunlight exposure Malabsorption Liver/kidney disease Vit D resistance Renal phosphate wasting eg. Fanconi's syndrome ```

Question 30

What are the signs and symptoms of osteomalacia?

Answer 30

``` Bone pain Weakness Malaise Waddling gait Proximal muscle weakness Signs of hypocalcaemia ```

Question 31

What are the signs and symptoms of Ricket's?

Answer 31

``` Hypotonia Growth retardation Skeletal deformities Frontal/parietal bossing Rickety rosary Bowed legs Knocked knees Short stature ```

Question 32

What are the investigations for Vit D def?

Answer 32

``` Bloods: -low/normal Ca -low PO4 -slightly raised ALP -high PTH (2 hyperPTH) ABG- for acidosis XR -may show Looser's zone and osteopenia Bone biopsy after double tetracycline labelling ```

Question 33

What is the management for Vit D def?

Answer 33

``` Restore Vit D: -ergocalciferol -cholecalciferol -Ca supplements If in renal failure: -alfacalciferol ```

Question 34

What are the complications of Vit D def?

Answer 34

``` Bone deformities (permanent in children) Hypocalcaemia: -seizure -arrhythmia -tetany Depression ```

Question 35

What is osteoporosis?

Answer 35

Reduced bone density, resulting in bone fragility and increased fracture risk.

Question 36

How is osteoporosis diagnosed?

Answer 36

If a Pt's DEXA is >2.5 S.D's below the peak bone mass in healthy adults (ie. T score)

Question 37

What is the epidemiology of osteoporosis?

Answer 37

>50yrs | Caucasians > Afro-Caribbeans

Question 38

What are the causes of primary osteoporosis?

Answer 38

Idiopathic

Question 39

What are the causes of secondary osteoporosis?

Answer 39

``` Malignancy- myeloma, carcinoma mets Endo- Cushing's Dx, thyrotoxicosis, 1 hyperPTH, hypogonadism Drugs- corticosteroids, heparin Rheum- RhA, ankylosing spondylitis GI- malabsorption, liver Dx, anorexia ```

Question 40

What are the risk factors for osteoporosis?

Answer 40

Age, ethnicity, FHx Alcohol, low Vit D nutrition Medication

Question 41

What are the signs and symptoms of osteoporosis?

Answer 41

Asymptomatic | Usually present after a fracture

Question 42

Which fractures are commonly associated with osteoporosis?

Answer 42

Neck of femur fracture Vertebral fracture Colles' fracture (distal radius)

Question 43

What are the investigations for osteoporosis?

Answer 43

Bloods- normal in primary XR- diagnose fractures Isotope bone scans DEXA scan

Question 44

What is Paget's disease of bone?

Answer 44

Excessive bone remodelling leading to deformities

Question 45

What is the aetiology of Paget's?

Answer 45

Overactivity of osteoclasts break down bone Lytic wedges form Compensatory osteoblast activity lays down trabecular bone, not lamellar bone Marrow becomes filled with fibrous tissue what is hypervascular

Question 46

What is the presentation of Paget's?

Answer 46

May be asymptomatic May have insidious onset of bone pain Headaches/dizziness Increasing skull size Bitemporal head enlargement with frontal bossing Spinal kyphosis Anterolateral bowing of femur/tibia/forearm Skin over the affected bone may be warm Sensorineural deafness (CN VIII compression)

Question 47

What are the investigations for Paget's?

Answer 47

``` ALP (very very high) Ca and PO4 normal Lytic and sclerotic bone lesions Skull changes Radioisotope bone scan- increased activity ```

Question 48

A 39-year-old man presents with a three-month history of depression. The patient recently lost a family member and around the same period began to feel unwell with constipation and a depressed mood. He has started taking analgesia for a sharp pain in his right lower back that often radiates towards his front. The most appropriate investigation is: ``` A. Serum parathyroid hormone B. Serum thyroid stimulating hormone C. Colonoscopy D. Fasting serum calcium E. MRI scan ```

Answer 48

D. Fasting serum calcium This patient appears to be suffering from symptoms of elevated calcium levels, these can include depression, constipation and renal stone formation causing abdominal pain.

Question 49

A 50-year-old woman presents to accident and emergency complaining of excessive lethargy. In addition, she mentions that she has been constipated. On examination, there are clinical features of dehydration. Blood tests have revealed a corrected calcium of 3.3 mol/L. Her chest x-ray shows bilateral streaky shadowing throughout both lung fields. She is given 3L of saline in 24 hours after admission. The following day her blood tests are repeated and her corrected calcium level is now 3.0 mmol/L. Results of parathyroid hormone levels and thyroid function tests are still awaited. What is the most appropriate management? A. Intravenous saline rehydration B. Intravenous saline rehydration and pamidronate C. Pamidronate D. Calcitonin E. Intravenous saline rehydration plus calcitonin

Answer 49

E. Intravenous saline rehydration Acute hypercalcaemia is an emergency that requires prompt treatment. The treatment of acute hypercalcaemia is saline, saline and more saline! Bisphosphonates (B) and (C) should be reserved for hypercalcaemia of malignancy. The most common causes of hypercalcaemia are hyperparathyroidism and malignancy. In light of the raised calcium, the chest x-ray findings should raise the suspicion of sarcoid or possible lymphangitis carcinomatosis. While a diagnosis of sarcoid must be confirmed with histology, hypercalcaemia in sarcoidosis is an indication for corticosteroid therapy. Therefore, this patient can be given a steroid challenge. If the calcium levels fall following this, it is suggestive of sarcoid. Administering bisphosphonates, however, would complicate the process of making the diagnosis of sarcoid as any correction in calcium following steroid therapy may have been produced by the bisphosphonate. Calcitonin (D) and (E) is seldom used in hypercalcaemia as it has a short- lived action and is painful upon intravenous administration.

Question 50

5. A 67-year-old man presents to his GP with pain in his pelvis. During the consultation, he mentions that his friends have been commenting that his head appears larger than before. In addition, he has noticed deterioration in hearing in his left ear. On neurological examination, a left-sided sensorineural deafness in detected. Closer inspection of the legs reveals bowing of the tibia. What is the most likely diagnosis? ``` A. Osteomalacia B. Osteoporosis C. Acromegaly D. Ricket's E. Paget’s disease ```

Answer 50

E. Paget’s disease