EFFECTS ON BONE MASS AFTER 8 YEARS OF HORMONAL REPLACEMENT THERAPY

Objective The purpose of this randomised double-blind placebo-controll ed study over two years followed by a six year open controlled extensi on phase was to investigate the effects of hormonal replacement therap y (HRT) both continuous combined HRT and sequential HRT) versus no tre atment on lumbar spine bone mineral density (L-BMD) and distal forearm bone mineral content (F-BMC). Further, bone mineral density of the pr oximal femur, lateral spine, and distal forearm was studied after eigh t years. Design Prospective study of normal, early postmenopausal wome n, initially in a double-blind, placebo controlled study, subsequently an open, controlled investigation. Setting Clinical physiology unit o f a general second degree referral hospital.Sample Seventy-three norma l, early postmenopausal women (HRT n = 47; placebo/untreated n = 26). Methods Dual photon absorptiometry, dual X-ray absorptiometry, single photon absorptiometry. Main outcome measures HRT resulted in a signifi cantly (P < 0.001) higher mean L-BMD after eight years, when it was 12 .1% higher than the mean initial value and 14.8% higher than the mean bone mineral density of the untreated group. L-BMD increased by 14.6% in women receiving continuous combined HRT compared with 11.1% in thos e on sequential HRT but intergroup differences were not statistically significant, Mean F-BMC measured with SPA decreased in the HRT group a nd in the placebo/untreated group by 0.2% and 14.8% (P < 0.001), respe ctively. However, after eight years mean F-BMC was 14.5% higher in the HRT group than in the placebo/untreated group, The study showed after eight years for all regions of the distal radius and ulna a significa ntly higher bone mineral density value compared with the placebo/untre ated group (P < 0.001). An especially large effect of HRT was found on the bone mineral density of the vertebral body of the 3rd lumbar vert ebra (L3), this one, measured by lateral scanning, being 18.7% higher than that of the placebo/untreated group. For the proximal femur, only the bone mineral density of Ward's triangle was significantly higher in the HRT group than in the placebo/untreated group. Conclusion Eight years of treatment with HRT resulted in a significant, substantial ga in of bone mineral density in the lumbar spine. The distal radius, uln a and Ward's triangle showed a significantly higher bone mineral densi ty in the HRT group compared with the placebo/untreated group.