PTH & HRT restore bone density

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Hi All,

Subcutaenous PTH (ParaThyroid Hormone) combined with HRT has shown a net growth

of osteoblast numbers, increased matrix,

calcium density & bone strength.

Normally PTH triggers osteoclast activity and causes the breakdown of bone & the

release of calcium into the blood.

However estrogen inhibits PTH activity on osteoclasts and low levels PTH also

triggers some osteoblast activity.

Here are two very positive studies on the use of subcutaneous PTH and oral HRT

which showed a substantial increase in

bone density.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=PubMed & list_uids=1\

1346808 & dopt=Abstract

N Engl J Med 2001 May 10;344(19):1434-41 Related Articles, Books, LinkOut

Effect of parathyroid hormone (1-34) on fractures and bone mineral density in

postmenopausal women with osteoporosis.

Neer RM, Arnaud CD, Zanchetta JR, Prince R, Gaich GA, Reginster JY, Hodsman AB,

sen EF, Ish-Shalom S, Genant HK,

Wang O, Mitlak BH.

Massachusetts General Hospital and Harvard Medical School, Boston, USA.

BACKGROUND:

Once-daily injections of parathyroid hormone or its amino-terminal fragments

increase bone formation and bone mass

without causing hypercalcemia, but their effects on fractures are unknown.

METHODS:

We randomly assigned 1637 postmenopausal women with prior vertebral fractures to

receive 20 or 40 microg of parathyroid

hormone (1-34) or placebo, administered subcutaneously by the women daily. We

obtained vertebral radiographs at base

line and at the end of the study (median duration of observation, 21 months) and

performed serial measurements of bone

mass by dual-energy x-ray absorptiometry.

RESULTS:

New vertebral fractures occurred in 14 percent of the women in the placebo group

and in 5 percent and 4 percent,

respectively, of the women in the 20-microg and 40-microg parathyroid hormone

groups; the respective relative risks of

fracture in the 20-microg and 40-microg groups, as compared with the placebo

group, were 0.35 and 0.31 (95 percent

confidence intervals, 0.22 to 0.55 and 0.19 to 0.50). New nonvertebral fragility

fractures occurred in 6 percent of the

women in the placebo group and in 3 percent of those in each parathyroid hormone

group (relative risk, 0.47 and 0.46,

respectively [95 percent confidence intervals, 0.25 to 0.88 and 0.25 to 0.861).

As compared with placebo, the 20-microg

and 40-microg doses of parathyroid hormone increased bone mineral density by 9

and 13 more percentage points in the

lumbar spine and by 3 and 6 more percentage points in the femoral neck; the

40-microg dose decreased bone mineral

density at the shaft of the radius by 2 more percentage points. Both doses

increased total-body bone mineral by 2 to 4

more percentage points than did placebo. Parathyroid hormone had only minor side

effects (occasional nausea and

headache).

CONCLUSIONS:

Treatment of postmenopausal osteoporosis with parathyroid hormone (1-34)

decreases the risk of vertebral and

nonvertebral fractures; increases vertebral, femoral, and total-body bone

mineral density; and is well tolerated. The

40-microg dose increased bone mineral density more than the 20-microg dose but

had similar effects on the risk of

fracture and was more likely to have side effects.

PMID: 11346808 [PubMed - indexed for MEDLINE]

==================

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=PubMed & list_uids=1\

1341338 & dopt=Abstract

J Bone Miner Res 2001 May;16(5):925-31 Related Articles, Books, LinkOut

Parathyroid hormone added to established hormone therapy: effects on vertebral

fracture and maintenance of bone mass

after parathyroid hormone withdrawal.

Cosman F, Nieves J, Woelfert L, Formica C, Gordon S, Shen V, R.

Clinical Research Center, Helen Hospital, New York State Department of

Health, West Haverstraw 10993, USA.

Our best pharmacologic agents for osteoporosis treatment prevent no more than

40-60% of osteoporotic fractures in

patients at highest risk. Thus, there is a need for agents that can further

augment bone mass and reduce fracture risk

more substantially. To this end, we investigated the utility of parathyroid

hormone (PTH) in combination with

established hormone-replacement therapy (HRT) in women with osteoporosis.

Fifty-two women who had been on HRT for at least 2 years were enrolled in this

trial in which 25 were assigned randomly

to remain on HRT alone and 27 were assigned to remain on HRT and also receive

daily subcutaneous PTH(1-34) 400 U (25

microg) per day for 3 years.

Bone mineral density (BMD) measurements at the spine, hip, and total body as

well as biochemical determinations of bone

turnover and calcium homeostasis were obtained every 6 months. Lateral thoracic

and lumbar spine X-rays were obtained at

baseline and annually. Subjects also had measurements of bone density and

biochemical indices of bone turnover 1 year

after discontinuation of PTH, while HRT was continued.

In the group receiving HRT alone, bone density and biochemical variables of bone

turnover remained stable throughout the

3-year treatment trial and 1-year follow-up.

In the PTH + HRT group, biochemical variables of bone formation and resorption

peaked at 6 months and subsequently

remained elevated until 30 months at which time levels were indistinguishable

from baseline.

Subjects in the PTH + HRT group increased bone mass by 13.4+/-1.4% in the spine,

4.4+/-1.0% in the total hip, and

3.7+/-1.4% in the total body. Bone density measurements remained stable 1 year

after discontinuation of PTH without any

significant loss while women continued HRT. Biochemical variables did not change

significantly after cessation of PTH

through the 1-year follow-up period.

PTH + HRT reduced the percent of women who had vertebral fractures from 37.5% to

8.3% (using a 15% height reduction

criterion) and from 25% to 0% (using a 20% height reduction criterion) compared

with women receiving HRT alone (p < 0.02

for both).

We conclude that ongoing HRT maintains almost all of the PTH-induced bone mass

increment for 1 year after

discontinuation of PTH.

Furthermore, PTH in combination with hormone therapy is an effective means of

increasing bone mass throughout the

skeleton and specifically reducing vertebral fracture occurrence by 75-100%,

compared with HRT alone.

PMID: 11341338 [PubMed - in process]

Greg