L17: Osteoporosis & MBD Flashcards
Def of Osteoporosis
Pathogenesis of Osteoporosis
Osteoporosis results from imbalance between bone formation and resorption due to:
- Increased bone breakdown by osteoclasts
- Decreased bone formation by osteoblasts.
Types of Osteoporosis
primary & secondary
Types of 1ry Osteoporosis
Type I (Postmenopausal osteoporosis)
Type II (Senile osteoporosis)
Secondary osteoporosis
Affects males and females at any age as a result of disease process or medications.
General Risk factors of Osteoporosis
General Risk factors of Osteoporosis
- Age
Affects 30% of over 50 years
General Risk factors of Osteoporosis
- Sex
Female ( Women four times more affected than men)
General Risk factors of Osteoporosis
- Race
Caucasian and Asian
Diseases predisposing to Secondary Osteoporosis
Diseases predisposing to Secondary Osteoporosis
- Endocrine
Cushing – Hyperparathyroidism – Thyrotoxicosis –
Hypogonadism - Diabetes mellitus.
Diseases predisposing to Secondary Osteoporosis
- Rheumatologic
RA arthritis - ankylosing spondylitis.
Diseases predisposing to Secondary Osteoporosis
- Deblitating Diseases
Chronic kidney disease (Renal Osteodystrophy) - Chronic liver disease - Chronic obstructive pulmonary disease.
Diseases predisposing to Secondary Osteoporosis
- Hematologic
myeloma - lymphoma and leukemia – hemophilia - sickle-cell disease and thalassemia.
Diseases predisposing to Secondary Osteoporosis
- Inherited
Osteogenesis imperfecta - Marfan syndrome
Medications predisposing to Secondary Osteoporosis
Medications predisposing to Secondary Osteoporosis
- Hormonal
Steroid-induced, L-Thyroxine, progesterone, Thiazolidinedione, Anti- androgens.
Medications predisposing to Secondary Osteoporosis
- CNS
Barbiturates, phenytoin, antiepileptics, lithium.
Medications predisposing to Secondary Osteoporosis
- Antimetabolite drugs
Methotrexate
Medications predisposing to Secondary Osteoporosis
- Anticoagulant drugs
heparin and warfarin.
Medications predisposing to Secondary Osteoporosis
- Antacids
Proton pump inhibitors and chronic oral antacids
CP of Osteoporosis
INVx for Osteoporosis
- Rads
- Labs
Rad INVx of Osteoporosis
- Conventional X-ray
- Dual energy X-ray absorptiometry (DEXA)
x-Ray in Osteoporosis
Shows vertebral compression fracture, cortical thinning, decrease in the number of trabeculae and increased radiolucency.
DEXA in Osteoporosis
- Is the gold standard in osteoporosis diagnosis usually of the lumbar spine and proximal femur
- It is precise, accurate, uses low dose of radiation.
T-Score in DEXA for Osteoporosis
Z-Score for DEXA in Osteoporosis
Matches BMD to age matched control
Labs in Osteoporosis
TTT of Osteoporosis
- Non-Drug Therapy & Drug Therapy
Non-Drug Therapy of Osteoporosis
Drug Therapy of Osteoporosis
- Anti-Resorptive Therapy
- Anabolic Therapy
Types of Anti-Resorpative Theray
- Bisphosphonates
- Hormone replacement therapy (HRT)
- Selective estrogen receptor modulator (SERMs)
- Androgen
- Calcitonin
- Supplementation with calcium and vitamin D
MOA of Bisphosphonates
are potent inhibitors of osteoclast activity.
Examples of Bisphosphonates
SE of Bisphosphonates
- …… has been associated with renal toxicity
- Bisphosphonates are not recommended for patients with impaired renal function.
Zoledronate
In which type of osteoporosis is Hormone replacement therapy (HRT) Used?
type I osteoporosis
MOA of Hormone replacement therapy (HRT)
Estrogen suppresses bone resorption by inhibiting osteoclasts.
SE of Hormone replacement therapy (HRT)
Because of adverse effects, HRT is a second-line option for osteoporosis except ……
in early postmenopausal women at high fracture risk who also have perimenopausal symptoms.
Example of Selective estrogen receptor modulator (SERMs)
Raloxifene
Indications of Selective estrogen receptor modulator (SERMs)
(Type I osteoporosis)
MOA of Selective estrogen receptor modulator (SERMs)
- It is not a hormone, it activates estrogen receptors in bone but has no stimulatory effect on the endometrium.
- So it inhibits the effect of PTH on osteoclast without trophic effect on breast or uterus
SE of Selective estrogen receptor modulator (SERMs)
May cause or worsen hot flushes and also increase the risk of thromboembolic disease
Indications of Androgen in osteoporosis
In men with osteoporosis who have clinical and biochemical evidence of hypogonadism, testosterone replacement is used.
Calcitonin in TTT of Osteoporosis
- Nasal or subcutaneous: it Slows bone loss
- Occasional nausea, vomiting, flushing may occur.
Supplementation with calcium and vitamin D in TTT of Osteoporosis
- In those with low dietary calcium intake and at risk from vitamin D insufficiency, calcium and vitamin D supplements should be advised,
- The recommended dose is 800 IU of vitamin D and 1–1.2 g calcium daily
Examples of Anabolic Therapy in TTT of Osteoporosis
Recombinant human parathyroid hormone peptide
- Teriparatide
MOA of Anabolic Therapy in TTT of Osteoporosis
Anabolic agents that stimulate bone formation.
Indications of Anabolic Therapy in TTT of Osteoporosis
Indicated in severe cases of vertebral osteoporosis or in women who fail to respond to other therapies.
Examples of Metabolic Bone Disease
1) Osteoporosis
2) Osteomalacia (see rheumatology)
3) Paget disease of the bone (Osteitis deformans)
Another name of Paget’s Disease
Osteitis deformans
Def of Paget’s Disease
- Is a disorder of increased bone resorption with compensatory increased bone formation (structurally abnormal)
Epidemeology of Paget’s Disease
- It affects men and women (2 : 3) over the age of 40 years.
- The prevalence of Paget disease increases with age ( Affects up to 10% of persons older than 80 years )
Etiology & Pathogenesis of Paget’s Disease
CP of Paget’s Disease
Complications of Paget’s Disease
INVx in Paget’s Disease
TTT of Paget’s Disease
