The effects of short-term hormone replacement therapy on long-term bone mineral density.
BACKGROUND
Short-term hormone replacement therapy (HRT) relieves menopausal symptoms and increases bone mineral density (BMD), but bone loss reoccurs upon discontinuation. This study assesses whether short-term HRT provides long-term BMD benefits.


METHODS
This was a prospective study of women aged 50-54 years followed up for 9 years. Women were categorized into three groups according to the treatment they received: No-HRT (n = 340), Short-term HRT (2-4 years, n = 60), and Long-term HRT (9 years, n = 187).


RESULTS
BMD increased significantly at the hip (2.4%, p < 0.001) and spine (8.0%, p < 0.001) over 9 years in the Long-term HRT group. Women without treatment lost BMD at the hip (-4.2%, p < 0.001) and spine (-3.5%, p < 0.001). Women in the Short-term HRT group had no significant loss of BMD at the hip (-1.6%, p = 0.08) or spine (-1.4%, p = 0.18) over 9 years. BMD in the Short-term HRT group was significantly higher at 9 years than in the No-HRT group at both spine (difference 0.023 g/cm(2), p = 0.048) and hip (difference 0.016 g/cm(2), p = 0.042).


CONCLUSIONS
After 9 years, women who had taken short-term HRT had no significant loss of BMD and were better off in terms of BMD than those left untreated. Short-term HRT in the early postmenopausal period provides long-term BMD benefits.
Middleton
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Centre for Metabolic Bone Disease, Hull Royal Infirmary, Hull, UK.
Steel
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D015502:Absorptiometry, Photon; D015519:Bone Density / Q000187:drug effects; D016022:Case-Control Studies; D004334:Drug Administration Schedule; D015914:Estrogen Replacement Therapy; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000187:drug effects; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000187:drug effects; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging / Q000473:pathology / Q000517:prevention & control*; D011446:Prospective Studies; D012720:Severity of Illness Index