osteo

2.  Osteoporosis is a disease where decreased bone
strength increases the risk of a broken bone. It is
the most common reason for a broken bone
among people who are old.[1] Bones that
commonly break include the back bones, the
bones of the forearm, and the hip.[2] Until a
broken bone occurs there are typically no
symptoms. Bones may weaken to such a degree
that a break may occur with minor stress or
spontaneously. Chronic pain and a decreased
ability to carry out normal activities may occur
following a broken bone.

3.  Bone is continually being formed and
resorbed. Normally, bone formation and
resorption are closely balanced.
 Osteoblasts- cells that make the organic
matrix of bone and then mineralize bone and
 osteoclasts- cells that resorb bone are
regulated by parathyroid hormone (PTH),
calcitonin , estrogen , vitamin D, various
cytokines, and other local factors such as
prostaglandins.

4.  Peak bone mass in men and women occurs by
the mid 20s. Blacks reach higher bone mass than
whites and Asians, whereas Hispanics have
intermediate values. Men have higher bone mass
than women. After achieving peak, bone mass
plateaus for about 10yr, during which time bone
formation approximately equals bone resorption.
After this, bone loss occurs at a rate of about 0.3
to 0.5%yr. Beginning with menopause, bone loss
accelerates in women to about 3 to 5%yr for
about 5 to 7yr and then the rate of loss
decelerates.

5.  Osteoporotic bone loss affects cortical and
trabecular (cancellous) bone. Cortical
thickness and the number and size of
trabeculae decrease, resulting in increased
porosity. Trabeculae may be disrupted or
entirely absent. Trabecular bone loss occurs
more rapidly than cortical bone loss because
trabecular bone is more porous and bone
turnover is higher. However, loss of both
types contributes to skeletal fragility.

7.  Primary osteoporosis
 More than 95% of osteoporosis in women and
probably about 80% in men is primary. Most
cases occur in postmenopausal women and
older men. Gonadal insufficiency is an
important factor in both men and women.
Other contributing factors may include
decreased Calcium intake, low vitamin D
levels, and hyperparathyroidism.

8.  SECONDARY OSTEOPOROSIS
Secondary osteoporosis accounts for < 5% of
osteoporosis in women but probably more in
men. The causes may also further accelerate
bone loss and increase fracture risk in patients
with primary osteoporosis.
Patients with chronic kidney disease may have
several reasons for low bone mass, including
hyperparathyroidism, renal osteodystrophy,
and adynamic bone.

9.  Bisphosphonates
 Bisphosphonates are synthetic analogs of
naturally occurring hydroxyapatites (bone
resorption inhibitors). They are considered
first-line therapy for the prevention and
treatment of osteoporosis. These agents have
been shown to increase bone mineral density
(BMD) as well as to decrease the incidence of
first and future fractures.

10. Bisphosphonates have poor oral bioavailability and can be
corrosive to the upper gastrointestinal (GI) tract. Strict
administration guidelines must be followed in order to improve
absorption and avoid significant upper GI problems, such as
nausea, stomach upset, and esophagitis. Bisphosphonates must
be taken on an empty stomach with a full glass of water after
getting up for the day. Patients also must be instructed to wait at
least 30 minutes before having their first food, beverage, or other
medication for the day and to remain upright for at least 30
minutes after taking a bisphosphonate dose.

11. CALCITONIN- SALMON a hormone that inhibits bone
resorption. It is available as a nasal spray or as an
injection, the nasal spray being the most
commonly used formulation. It is approved for the
treatment of osteoporosis, and study results
indicate increased spinal bone density and possible
relief of pain associated with spinal fractures.
Therapy with calcitonin-salmon should be reserved
for postmenopausal women or women who cannot
tolerate other therapy. Side effects generally are
local reactions to the nasal spray.

12.  Calcium
 Calcium should be considered an important
antiresorptive agent that can significantly
enhance the action of other treatment
modalities.

13.  Parathyroid Hormone
 Teriparatide is the newest agent approved for
the treatment of osteoporosis, and it is the
first drug to stimulate new bone growth. It is
available as an injection that contains
recombinant human parathyroid hormone.