Metabolic Bone disease: Things I didn’t understand as a Medical student/ FY1/ SHO/ SPR

1. Metabolic Bone disease:Things I didn’t understand as a Medical student/ FY1/ SHO/ SPR James Bateman Arthritis Research UK Educational Research Fellow

2. Aims and Objectives • Aims • Understand the definition and spectrum of metabolic bone diseases • Objectives • demonstrate understanding of epidemiology, aetiology, clinical features and management of osteoporosis, osteomalacia, Paget’s disease and renal osteodystrophy

3. Case 1 • 72 year old lady • Acute onset severe thoracic pain • Keeping her awake at night • Radiates around ribs • No history of trauma • PMH – COPD • DH - Inhalers • What other questions would you ask?

4. Case 1 - contd • On examination – • Frail lady • Apyrexial • Thoracic kyphosis • Tender over spinous processes T7/8 • No neurological deficit • differential diagnosis?

5. Diff. Diagnosis of Back Pain • Simple mechanical eg ligamentous strain • Degenerative disease with/without neural, cord or canal compromise • Metabolic – osteoporosis, Pagets • Inflammatory – Ankylosing spondylitis • Infective – bacterial and TB • Neoplastic • Others, (trauma,congenital) • Visceral

6. Case 1 • Investigations • HB 12.9, WCC 9.0, Plts 245 • Na 139, K 4.4, U 7.3, Cr 96 • Alk Phos 297, ALT 32, Bil 13, Ca 2.41 • CRP 8

8. Osteoporosis Reduction in bone mass leading to increase risk of fracture Ratio of mineralised bone: “matrix is normal” Imbalance of bone remodelling

11. Risk factors for osteoporosis?

13. Measurement and definition of OP?

15. T scores

17. Typical OP # ?

18. OP fractures

20. 250,000 # / yr in UK

21. Treatment for OP ?

22. Osteoporosis • Lifestyle factors • Falls prevention • Hip protectors • Ca and Vit D

23. Bisphosphonates • Strontium • SERMs • Teriparatide- PTH

24. Preventing steroid induced osteoporosis • All: lifestyle advise, calcium and vit D • Age <65 DEXA- if T score -1.0 or less then alendronate • Age >65 alendronate

25. NICE guidance • http://guidance.nice.org.uk/TA87/?c=91524 • www.sheffield.ac.uk/FRAX/tool

27. Case 2 • 33 year old Asian lady • Presents with 3 /12 history of generalised bony pain • PMH – depression • DH – sertraline • O/E – generalised bony tenderness • Joints – normal ROM, no inflammation

28. Investigations • Hb 12.9 (11.5-16.5) Calcium 2.18 (2.2-2.6) • WCC 4.7 (4.9-11.0) Phosphate 0.79 (0.85- 1.45) • Plt 253 (150-400) Albumin 39 (35-50) • ESR 12 Alk Phos 172 (25-96) • Clotting Normal Total protein 72 (60-80) • Urea 4.2 (3.0-6.5) LFTs normal • Creat 85 (35-120)

29. Diagnosis?

30. Osteomalacia • Rickets of adulthood • Deficiency OR resistance to Vit D OR Phosphate handling problem • Defective mineralization of bone • Proximal myopathy, Bony pain, malaise • Deformities much less common than with rickets • AP raised, Ca and Vit D low or normal • PO4 low or normal

32. What I didn’t understand as a medical student… • Bone remodelling is a continuous process with uptake and laying down of new matrix (osteoid) and its mineralisation (Ca&PO4) • In osteomalacia: the osteoid is normal (the matrix laid down by the osteoblasts) • Normally calcium and phosphate are then ladi down some 15 dyas later, and converted to hydroxyapatite)

33. What I didn’t understand as a medical student… • You need enough phosphate to mineralise bone: • PTH stops you the renal re-absorbtion of phosphate • So that’s why osteomalacia happens with vitamin D deficiency

34. Causes?

35. Causes of osteomalacia/rickets • Reduced availability of Vit D • Diet: oily fish, eggs, breakfast cereals • Elderly individuals with minimal sun exposure • Dark skin, skin covering when outside • Kidney failure • malabsorption

36. malabsorption • Coeliac • Intestinal bypass • Gastrectomy • Chronic pancreatitis • Pbc • Epilepsy: phenytoin, phenobarbitones

37. Defective metabolism of Vitamin D • Chronic renal failure, Vit D dependent rickets, • Liver failure, anticonvulsants • Receptor Defects • Altered phosphate homeostasis • Malabsorption, RTA, hypophosphatasia (rare, low levels of alk phos)

38. Loosers zones

39. Treatment • Vitamin D –usually oral- HIGH DOSE • Calcium supplements

40. Case 3 • 62 year old lady referred with generalised muscular pain • PMH – hypertension • DH – bendrofluazide • Examination – largely unremarkable • Routine bloods all normal except Calcium of 2.95 • She has come back to clinic for results • What would you do now?

41. Symptoms of hypercalcaemia • Stones, • Bones, • Moans, • Psychic Groans

42. An approach to hypercalcaemia • Stones, Renal colic • Bones, Joint, bone, muscle pain, Muscle weakness • Moans, Constipation Abdominal pains • Psychic GroansDepression, confusion, altered mental state, Fatigue, lethargy • Dehydration, polyuria

43. Causes of Hypercalcaemia?

44. Causes of Hypercalcaemia • Malignancy • Hyperparathyroidism – primary or tertiary • Increased intake • Myeloma • Sarcoid • Adrenal failure

45. Treatment of acute hypercalcaemia?

46. Treatment of acute hypercalcaemia • Hydration, IV if Ca very high • Bisphosphonates • Treat cause

47. Hyperparathyroidism • Primary hyperparathyroidism: • Often an incidental finding • May be part of MEN I, MEN II • Secondary hyperparathyroidism • Compensates for chronic low Ca eg. Renal failure or malabsorption • [Ca2+] and [PO42-] normal PTH high • Tertiary hyperparathyroidism • Hyperplasia in longstanding secondary disease

48. Multiple endocrine neoplasia • Aut dom • MEN 1 parathyroid tumours, ant pituitary, pancreas • MEN 2A thyroid tumour, phaeochromocytomas, parathyroid hyperplasia • MEN 2B thyroid tumours and phaeos

49. Hypoparathyroidism Causes • Destruction of gland- surgical (thyroidectomy- may be transient) • Autoimmune- polyglandular autoimmune glandular syndrome • Irradiation or infiltration (cancer, wilsons) • Abnormal gland development

50. Case 4 This 73 year old lady was referred from her GP to ENT with deafness. They asked her to see the rheumatologist Why?