Estrogen
is the
only clearly effective treatment. Low
estrogen levels cause a gradual loss of bone calcium. Youthful estrogen levels not only stop this
loss but cause a modest increase in bone density. Avoid bisphosphonates because they increase
bone density by going to the bone but done strengthen them. There is no reduction in fractures and an
association with at least 2 issues, femur fracture and deterioration of the mandible.
Osteoporosis
Merck: Osteoblastic (cells that make the organic matrix of bone and then mineralized bone) and osteoclasts
(cells that reabsorb bone) are regulated by parathyroid hormone (PTH), calcitonin, estrogen, vitamin D, cytokines (e.g. interleukin-1,
tumor necrosis factor alpha, granulocyte-macrophage colony-stimulating factor, interleukin-6) and other local factors such
as prostaglandins. After the age of 30 bone loss occurs at the rate of 0.3 to
0.5% per year. Beginning with menopause bone loss accelerates in women to about
3 to 5% /year for about 5 to 7 years. Because stress is necessary for bone growth,
immobilization or extended sedentary periods results in bone loss.[i] Cigarette smoking (inhibits the activity of osteoblasts)
and excessive caffeine or alcohol use adversely affect bone mass. Bisphosphonates
are the first line drug therapy. Diagnosis is by dual energy X ray absorptiometry
(DXA or DEXA). Exercise reduces risk.[ii]
Conns Therapy 2002:
Alendronate
& glucocorticoid induced osteoporosis
Nearly all postmenopausal women will lose bone mass if not receiving specific ERT therapy despite receiving adequate
calcium and vitamin D. (Prostesterone is needed to protect against uterine estrogen
effects.) Early preventive postmenopausal bone loose will help prevent fragility
fractures later in life. A bone density of -2.5 S.D. at the age of 70 has a 10-year
hip-fracture risk of 24% (both men and women). The osteoporosis field is being
damaged by calcium marketers who claim that calcium alone is adequate. For elderly
women who were previously estrogen users, but had discontinued estrogen for over 5 years, both their BMD and fratyur4e rates
may differ little from those women how had not previously taken estrogen. 90%
of hip fractures occur after a fall; therefore treatment which reduce the risk (exercise, improving eyesight, and reducing
use of nervous system altering drugs reduce the tendency to fall). Heritability
ranges from 25-80%. There are at least 30 genes associated with the development
of osteoporosis. Those who have a fracture are at least twice as likely to have
another fracture compared to someone of the same age and sex.
Goodman & Gilman
(2007)
Osteoporosis
is a condition of low bone mass and microarchitectural disruption that results in fractures with minimal trauma. Between 30% and 50% of women and between 15% and 40% of men suffer a fracture related to osteoporosis.
It is defined in women as a bone mineral density of 2.5 standard deviations below peak bone mass (20-year-old healthy female
average). Type I osteoporosis is
characterized by loss of trabecular bone owing to estrogen lack at menopause, and type
II osteoporosis is characterized by loss of cortical and tabular bone in men and women owing to long-term remodeling inefficiency,
dietary inadequacy, and activation of the parathyroid axis with age. The disease
is a result of multiple physical, hormonal, and nutritional factors acting alone or in concert. Secondary osteoporosis (accounts for <5% cases) is due to
systemic illness or medications such as glucocorticoids or phenytoin[iii]. {Glucocorticoid any of a group of steroid hormones, such as cortisone, that are produced by the adrenal cortex,
are involved in carbohydrate, protein, and fat metabolism, and have anti-inflammatory properties. Phenytoin: An anticonvulsant drug, C15H12N2O2,
used most commonly in the treatment of epilepsy--also called diphenylhydantoin.
Treatment is of two types, those that reduce bone resorption, (anti-resorptive
therapy) and by promoting bone formation (anabolic therapy). Since bone remodeling
is a coupled process, anti-resorptive drugs ultimately decrease the rate of bone formation.
Until recently, anti-resorptives were the only drugs approved in the US for treating osteoporosis. The increase in bone density is general under 10% after 3 years.
. The situation changed in 2002 when the FDA approved the biologically
active PTH fragment for use in treating postmenopausal women with osteoporosis and to increase bone mass in men with primary
or hypogonadal osteoporosis.
Antiresorptive agents, bisphosphonates
have emerged as the most effective drugs. Alendronate and risedronate have sufficient
potency to suppress bone resorption at doses that do not inhibit mineralization. The results of 10-year daily treatment with 10 mg of alendronate (supplemented with
500 mg of calcium)reported a 14% increase of lumbar spine BMD, and a smaller increments at the trochanter, total hip, and
femoral neck. On reduction and discontinuation of treatment BMD at the lumbar
spine was maintained, but not at the hip and neck. Risedronate for women with
low bone density but no previous vertebral fracture displayed increased of lumbosacral and femoral neck BMD with a significant
reduced risk of first vertebral compression fracture.
Calcium: Although little effect
of calcium on trabecular bone has been reported, reduction in cortical bone loss has been observed, and in elderly subjects
calcium supplements suppress bone turnover, improves BMD, and decreases the incidence of fractures. Traditional dosing of calcium is about 1000 mg/day, nearly the amount in a quart of milk.
Vitamin D and its analogs. Modest
supplementation may improve intestinal Ca+2 absorption, suppress bone remodeling, and improve BMD in individuals
with marginal deficient vitamin D status. A
prospective study found that neither dietary calcium nor vitamin D intake was of major importance for the primary prevention
of osteoporotic fractures in women (1672).
Estrogen. There
is an unambiguous relationship between estrogen
deficiency and osteoporosis. Likewise,
overwhelming evidence supports the positive impact of estrogen replacement on
the conservation of bone and protection against osteoporotic fractures after
menopause. Raloxifene (EVISTA) acts as an estrogen
agonist on bone and liver, is inactive on the uterus, and acts as an antiestrogen in the breast {which would accelerate the
sagging of the breasts with age}.
{The assorted other benefits of estrogen entail
that this would be the drug of choice--contrary to the press generated by Big
PhARMA}
Calcitonin: inhibits osteoclastic bone resorption and modestly increases
bone mass in patients with osteoporosis; the largest increase occurred in patients with high intrinsic rates of bone turnover.
Combination Therapies: Teriparatide
stimulates bone formation, bisphosphonates reduce bone resorption, thus it is presumed that the combination would enhance
the effect on BMD. However, addition of alendronate to PHT treatment provided
no additional benefit for BMD.
[i] Physical activity
has its greatest impact during adolescence. In adults, physical activity helps
maintain bone mass, and can increase it by 1 to 2 %. Excessive physical activity
can lead to damage; there are numerous examples of marathon runners who developed severe osteoporosis later in life, and in
women heavy exercise can lead to decreased estrogen levels.
[ii] Multiple studies
have shown that aerobics, weight bearing, and resistance exercises can all maintain or increase BMD in post-menopausal women. One years of regular jumping exercise increase BMD.
Exercise combined with HRT has been shown to increase BMD more than HRT
alone (Wikipedia).
[iii] Barbiturates, phenytoin, and some other enzyme-inducing
anti-epileptics—probably through the accelerated metabolism of vitamin D. Other
drugs include L-thrroxine (for under-active thyrroid), anticoagulant heparin and warfarin, proton pump inhibitors (inhibit
production of stomach acids) through their interference with calcium absorption; chronic phosphate bind with aluminum-containing
anti-acids; thiazolidinediones (used for diabetes) resiglitazone and pioglitazone inhibitors of PPARy; and chronic lithium
therapy (Wikipedia.org).