Metabolic bone dz Flashcards
Osteoporosis
Most common metabolic bone dz in the US.
Imbalance of bone homeostasis
PTH Causes…
Increased Ca resorption in tubules
Increased osteoclast activity
Conversion of Vitamin D to active form
Increased Ca abs in GI
Thyroid and Bone
Hyperthyroid stimulates clastic activity
What does the thyroid release with high serum calcium?
Calcitonin
Inhibits clasts
Osteoporosis Pneumonic
Low calcium intake
oSteoporosis Pneumonic
Seizure meds
osTeoporosis
Thin build
ostEoporosis
ETOH
osteOporosis
Hypogonadism
osteoPorosis
Previous fracture
osteopOrosis
Thyroid excess
osteopoRosis
Race (white, asian)
osteoporOsis
Other relatives (genetics)
osteoporoSis
Steroids
osteoporosIs
Inactivity
osteopososiS
Smoking
DEXA scan
Dual-energy x-ray absorptiometry
Test to eval bone mineral density
Osteoporosis medical tx
Calcium
VItamin D
Exercise
Calcium dose
1200 mg daily
Citrate is better absorbed if concominant use of acid blocking agents
Vitamin D dose
800 IU DR daily
Bisphosphonate MOA
Inhibit bone resorption by decreasing number and fxn of osteoclasts
Bisphosphonate CI
Barrett’s esophagus
Active upper GI dz
If GFR not greater than 30-35
Bisphosphonate types
Alendronate (Fosamax)
Risedronate (Actonel)
Zoledronic acid (Reclast)
Ibandronate (Boniva)
What must patient do post bisphosphonate dose?
Remain upright for 30 - 60 mins
Bisphosphonate SE
Reflux, esophagitis Ulcers Esophageal CA? Hypocalcemia MS Pain Eye pain, blurred vision Osteonecrosis of the jaw
Estrogen agonists
Less effective that estrogen and bisphosphonates.
SE: DVT, hot flashes, cancer
Calcitonin
Reduces risk for vertebral body fxs
Antagonizes PTH
Miacalcin or fortical
Hormone therapy
Initiate if other tx options have failed
Prempro
SE: MI, CVA, Breast CA, PE, DVT
Parathyroid hormone replacement
Forteo
Actually builds bone
Use if bisphosphonates fail
Pagets dz of the bone
2nd most common metabolic bone dz
Lesions can occur at various sites
Common paget sites in descending order
Skull Thoracolumbar spine Pelvis long bones LE
Pagets patho
Dz of osteoclasts Increased bone remodeling Genetic, onset after 55 Mostly men Associated w/ osteosarcoma
T-score of -1.0 to -2.5 =
Osteopenia
T-score of less than -2.5
Osteoporosis
Pagets s/s
Arthritis, pain Bone deformity/ fractures Hearing loss, HA, vertigo, tinnitus High output heart failure Hypercalciuria Increased incidence of stones
Pagets labs
Increased alkaline phosphatase
Pagets imaging
Mixed lytic and sclerotic lesions
Long bone bowing
Bone thickening and enlargement
Pagets tx
Vitamin D, Calcium
Bisphosphonates
Osteomalacia
Decreased mineralization of newly formed bone
Bone is soft, but no matrix loss
2 main causes of osteomalacia
Insufficient Ca abs in intestine Phosphate deficiency (celiac sprue, kidney, hepatic dz)
Osteomalacia s/s
Bone pain and muscle weakness
Bone tenderness
Fracture
Difficulty walking
Osteomalacia imaging
Reduced bone density w/ thinning of cortex
Fissures, pseudofractures
Looser’s lines
Fractures from osteomalacia
Osteomalacia tx
Tx underlying condition
Vitamin D supplementation
Most common fx sites in osteomalacia
Distal radius and prox femur
NOT significant cause of hip fxs
Rickets
Deficient mineralization at growth plate
Usually occurs w/ osteomalacia if growth plates have not fused.
Rickets cause
Vitamin D and calcium deficiency
Rickets Imaging
Bow legs
Renal osteodystrophy
Bone dz secondary to kidney dz
Osteitis fibrosis
High turnover secondary to hyperPTH
Adynamic bone dz
Low turnover.
Most common CKD bone dz
PTH suppression
Is osteomalacia common in CKD?
not really