Week 13 - Osteoporosis Flashcards
How many women will have an osteoporotic fracture in their lifetime?
1/3
How many men will have an osteoporotic fracture in their lifetime?
1/5
__% of all fractures (>50yo) = d/t osteoporosis
80%
__% of women and __% men will die within following year of hip fracture
28% women
37% men
Osteoporotic fracture DDX
malignancy primary hyperparathyroidism osteomalacia Paget's disease osteogenesis imperfecta
define hyperparathyroidism
Hyperparathyroidism is overactivity of the parathyroid glands resulting in excess production of parathyroid hormone (PTH). The parathyroid hormone regulates calcium and phosphate levels and helps to maintain these levels. Excessive PTH secretion may be due to problems in the glands themselves, in which case it is referred to as primary hyperparathyroidism and which leads to hypercalcaemia (raised calcium levels). It may also occur in response to low calcium levels, as encountered in various situations such as vitamin D deficiency or chronic kidney disease; this is referred to as secondary hyperparathyroidism. In all cases, the raised PTH levels are harmful to bone, and treatment is often needed.
define Paget’s disease
A chronic disorder that can result in enlarged and misshapen bones. Paget’s is caused by the excessive breakdown and formation of bone, followed by disorganized bone remodelling. This causes affected bone to weaken, resulting in pain, misshapen bones, fractures and arthritis in the joints near the affected bones. Rarely, it can develop into a primary bone cancer known as Paget’s sarcoma. Often Paget’s disease is localized to only a few bones in the body. The pelvis, femur, and lower lumbar vertebrae are the most commonly affected bones.
What is the action of PTH - parathyroid hormone
Parathyroid hormone (PTH), parathormone or parathyrin, is secreted by the chief cells of the parathyroid glands as a polypeptide containing 84 amino acids. It acts to increase the concentration of calcium (Ca2+) in the blood, whereas calcitonin (a hormone produced by the parafollicular cells (C cells) of the thyroid gland) acts to decrease calcium concentration. PTH acts to increase the concentration of calcium in the blood by acting upon the parathyroid hormone 1 receptor (high levels in bone and kidney) and the parathyroid hormone 2 receptor (high levels in the central nervous system, pancreas, testis, and placenta). PTH half-life is approximately 4 minutes.
Define osteoporosis
- skeletal SYSTEMIC disorder
- low bone mass
- microarchitectural deterioration of bone
- increased incidence of fragility fractures
Dx tests for osteoporosis
BMD via DEXA scan CBC (nutrition/myeloma) TSH (hypothyroid) Vitamin D calcium albumin creatinine alkaline phosphatase
What is the BMD cutoff below mean for dx osteoporosis?
Spinal/hip bone mineral density (BMD) of 2.5 standard deviation (or more) below mean for healthy, young adult as per duel energy x-ray absorptionmetry (DEXA)
What is the SD value criterion for Osteopenia
1-2.5 SD
What is the SD value criterion for severe osteoporosis
> 2.5 + fragility fracture
What is the SD value criterion for normal
<1 SD
What is a “fragility fracture”
occurs spontaneously or following minor trauma (fall from standing height or less)
High risk medications for development of osteoporosis
- corticosteroids
- PPIs
- thiazolidinedione
- aromatase inhibitors
- anticonvulsants
- anticoagulants
- SSRIs
Type I primary osteoporosis criteria: age
51-75 yo
Type I primary osteoporosis criteria: what kind of bone loss
trabecular