BACKGROUND AND OBJECTIVE Amenorrhoea in women of reproductive age caus
es loss df bone mineral. This study assessed the effect of treatment o
f amenorrhoea on bone mineral density. DESIGN Serial measurements of b
one mineral density were obtained in women receiving treatment for ame
norrhoea. PATIENTS Eighty-five women aged 17-40 with a past or current
history of amenorrhoea, from various causes, with median duration of
46.5 months (range 8 months-21 years). MEASUREMENTS Bone mineral densi
ty in the lumbar spine was measured by dual-energy X-ray absorptiometr
y. RESULTS Initial vertebral bone mineral density was low, mean 0.85 (
SD 0.10) g/cm(2). After an interval of 19.6 (SD 7.5) months on treatme
nt there was a highly significant increase to 0.89 (SD 0.10) g/cm(2) (
P < 0.0005). This was equivalent to a gain in bone mass of 2.1% per ye
ar (95% confidence interval 1.5-2.8%). Improvement was seen in all dia
gnostic groups (except polycystic ovary syndrome) and with all types o
f therapy. We observed no difference in the response of previously unt
reated patients compared with those already on treatment, nor any chan
ge in response with increasing duration bf treatment. No new fractures
were reported during the study. CONCLUSIONS Bone mineral density in y
oung women with amenorrhoea is improved by appropriate treatment, but
recovery is not substantial. Hence early diagnosis and therapy is esse
ntial to prevent bond loss.