Metabolic bone diseases and osteoporosis

Question 1

what is osteoporossis

Answer 1

reduce bone density and mass

equal loss of mineral and organic matrix

increase risk of fractures

• Bone reportion exceeds formation

Question 2

what are the risk factors for osteoporosis?

Answer 2

• Female (lower bone mass and oestorgen decrease in postemenopausla women)
  
  • most bone loss in first 10 years after menopause or oophorectomy
• Genetic
• ethnicity (northern europena and asian)
• Smoking and alcohol
• immobilisation (low physical actiivty)
• durg induced (corticosteriods- inhbit bone formation)
• testerone defivnecy (men)

Question 3

what are the majro risk factors of osteoporossis

Answer 3

Major- hisotry of fracture as an adulkt

fragility fracture in 1st degree relative

low body weight (<127 lbs)

Question 4

What is a DEXA scan?

Answer 4

Dual energy Xray absorptiometry

diagnosisa anf assess risk of osteoporosis

measures bone mineral desnity for example before treatmentt hat may have adverse effect on bone density (sec hormeon deprivation breats/prostate cancer)_

Question 5

what is osteomlacia?

Answer 5

inadequate bone mineralsiation of new born matrix/osteoid (softening of the bones)

ratio of mineral to organic is lowet than normal

Question 6

what is rickets?

Answer 6

osteomalacia in children

defecit bone mineralsixation at the ephiyseal growth plates

long bones cannot supporot weight of torsoa bones are flexible

Question 7

what are the causes of rickets?

Answer 7

defieinctintake or absoprtion of vitamin D

defective 1-alpha hydroxylation (CKD)

primary renal PO4 wasting

inhvitors of minerlalsation

defceitve vitamin D receptors

Question 8

what are the clinical features of ricekts at birth?

Answer 8

Craniotabes

softening occpital bones

flattened parietal bones can be buckled

Question 9

in earyl years what are the signs of rickets?

Answer 9

widened epiphyses (wrists)

frontal bossing (squared appearance to head)

Prescen of rickety rosary (beeding at costal chondral joints

Harriosns sulcus

Pigeon chest

Question 10

what are the symptoms of rickets in older children

Answer 10

Lower limb deformity

myopathy

lumbar lordodsis and bwoing of legs

Hypocalcemia tetany

Question 11

what are the clinical features of osteomlaaica

Answer 11

usually asymptomatic

symptomatic

• proximal msucle weakness
• widespread bone pain (tendeness)
• dull pain worse on weight bearing
• insuffiency fracture
• wasddling gait

Question 12

what are the main causes of hypercalcaemia??

Answer 12

• Primary hypoparathyroidism
  
  • Ca2+ homeotstasi loss due to excessive PTH secretion
  • due to benign parathryoid tumoru (adenoma) or hyperplastic parathryoid hormone)
  • excessive bone resportion
  • excessive PTH- excessive production of 1,2DHCC (more absoprtion from intes and more reasboprtion in kidneys
  • depsoit of calcium in heart lungs and soft tissue
• Malignant disease
  
  • ​metasses in the bone cause destriction and release of Ca2+ (would see low levekls of PTH in response to hyperclacaemia)
  • Metases also secret parahtyroiud hormone related peptide

Question 13

what are the causes of hypocalacaemia

Answer 13

hypoparathryoidism

pseudohypoparathyoidism

vbitamin D defieicny and dependnecy

renal disease

Inadaqueaet response of VTH-vitamin D axis

Question 14

how can renal disease result secondary hyperparathrypodms

Answer 14

lose so much calcoium due to kidney disease

get secondary hyperparathyroidsism as the body tries to increase levesl fo calcium in the blood by pulling it from the bones

Question 15

what is pseudohypoparathryodisim?

Answer 15

target organ resistance to PTH (not hormoen defieiocm)