G. Khastgir et al., Anabolic effect of estrogen replacement on bone in postmenopausal women with osteoporosis: Histomorphometric evidence in a longitudinal study, J CLIN END, 86(1), 2001, pp. 289-295
It is well recognized that estrogen (E-2) prevents postmenopausal bone loss
by suppressing bone resorption. Despite evidence that E-2 may also stimula
te bone formation in animals, an anabolic effect in humans is still controv
ersial. To investigate this, we studied 22 older postmenopausal females, wi
th a mean age of 65.4 yr and mean interval of 16.9 yr since menopause and l
ow bone mineral density. Transcortical iliac bone biopsies were performed b
efore and 6 yr after E-2 replacement therapy (ERT) [75 mg percutaneous E-2
replaced 6-monthly plus oral medroxy progesterone acetate (5 mg daily) for
10 days each calendar month]. The mean serum E-2 level after 6 yr of treatm
ent was 1077 (range, 180-2568) pmol/L. Bone mineral density improved in eve
ry patient, with a median increase of 31.4% at the lumbar spine and 15.1% a
t the proximal femur. Bone histomorphometry showed an increase in cancellou
s bone volume from 10.75% to 17.31% (P < 0.001). The wall thickness after 6
yr of E-2 treatment was 38.30 <mu>m compared with 31.20 mum before commenc
ement of ERT (P < 0.0005), indicating net bone gain. This is the first repo
rt showing histological evidence for an increase in cancellous bone volume,
together with an increase in wall thickness, in a longitudinal follow-up s
tudy of ERT in older postmenopausal women. Our results show that E-2 is cap
able of exerting an anabolic effect in women with osteoporosis, even when s
tarted well into the menopause.