Parathyroid increases bone density

[Guest guest]

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

1341338 & dopt=Abstract

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.

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

Good Health & Long Life,

Greg ,

http://www.ozemail.com.au/~gowatson

gowatson@...