Skeletal Effects of Cyclic Recombinant Human Growth Hormone and Salmon Calcitonin in Osteopenic Postmenopausal Women1

• Published in: The journal of clinical endocrinology and metabolism Vol. 82; no. 4; pp. 1111 - 1117
• Main Authors: Holloway, Leah, Kohlmeier, Lynn, Kent, Kyla, Marcus, Robert
• Format: Journal Article
• Language: English
• Published: Endocrine Society 01-04-1997
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jcem.82.4.3901

The objectives of this study were to determine whether cyclic
administration of recombinant human GH, with or without the
antiresorptive agent, salmon calcitonin (CT), provides clinically
meaningful increases in bone mineral density (BMD) at the lumbar spine
and proximal femur in postmenopausal osteopenic women.
The design of the study was a randomized clinical trial consisting of
12 56-day treatment cycles. Each cycle was initiated by a 12-day period
of hormone administration, followed by 44 days of supplemental calcium
only. Cycles of hormone administration consisted of 7 daily injections
of recombinant GH (20 μg/kg·day) or its placebo, followed by 5
daily injections of salmon CT (100 U/day) or its placebo. The study was
performed at the Palo Alto Veterans Affairs medical center.
The patients were 84 healthy women with lumbar spine BMD more than 1
sd below the average value for a healthy 25-yr-old
Caucasian woman. BMD was measured at the lumbar spine and proximal
femur by dual energy x-ray absorptiometry. Biochemical markers of bone
turnover and circulating insulin-like growth factor I were also
measured.
GH treatment increased insulin-like growth factor I concentrations from
low values at baseline (112 ± 56 ng/mL) to the young normal range
(∼430 ± 125 ng/mL). Groups receiving GH plus CT or GH plus
placebo increased lumbar spine BMD at 2 yr by 2.70 ± 0.81%
(P < 0.01) and 1.72 ± 0.74%
(P < 0.05; intention to treat analysis). No
significant change occurred in women receiving placebo plus CT or
combined placebo. Significant increases in total hip BMD of 1–2% were
observed for the GH plus placebo and placebo plus CT groups, with a
nonsignificant trend in the GH plus CT group. For the femoral
trochanter, significant increases were observed in the GH plus CT and
placebo plus CT groups only. No significant change in femoral neck BMD
was observed in any group.
Women taking replacement estrogen had the same BMD response as those
who were estrogen deficient. No significant increase in BMD was
observed between 24 and 36 months in the 62 women who returned for a 3
yr measurement. In response to GH, short term increases in resorption
and formation markers were observed, but these had decreased before the
next treatment cycle. No long term changes in resorption markers were
observed, but women in the GH groups showed a sustained rise in
circulating osteocalcin over the entire 2-yr protocol.
GH given cyclically with or without CT for 2 yr achieved statistically
significant increases in BMD of the lumbar spine and selected areas of
the hip in postmenopausal women. These gains were less marked than
those achieved with estrogen or bisphosphonates and were associated
with a relatively high incidence of adverse experiences. Therefore, it
is unlikely that cyclic GH with or without CT will prove clinically
useful in the treatment of postmenopausal women with osteoporosis.