Comparison of the effects of raloxifene and low-dose hormone replacement therapy on bone mineral density and bone turnover in the treatment of postmenopausal osteoporosis

Abstract

The aim of the present study was to compare the effects of raloxifene and low-dose hormone replacement therapy (HRT) on bone mineral density (BMD) and bone turnover markers in the treatment of postmenopausal osteoporosis. Forty-two postmenopausal osteoporotic women, who were randomized to receive raloxifene 60 mg or estradiol 1 mg/norethisterone acetate 0.5 mg daily for 1 year, were studied. All women received calcium 600 mg/day and vitamin D 400 IU/day. BMD and markers of bone turnover were measured at baseline and at 12 months. After 12 months of treatment, there were statistically significant increases in BMD in both groups at all sites (all p < 0.05). For the lumbar spine, the increase in BMD was 2.3% for raloxifene compared with 5.8% for low-dose HRT and corresponding values for total body BMD were 2.9% for raloxifene and 4.6% for low-dose HRT; the increases being significantly greater in the low-dose HRT group (p < 0.001 and p = 0.02, respectively). Although the increase in BMD at the hip was significant for both raloxifene (2.1%) and low-dose HRT (3.2%) compared with baseline, the difference between the two regimens did not reach statistical significance. The decrease in serum C-terminal telopeptide fragment of type I collagen and serum osteocalcin levels for the low-dose HRT group (-53% and -47%, respectively) was significantly greater than for the raloxifene group (-23% and -27%, respectively; both p < 0.01). In postmenopausal women with osteoporosis, low-dose HRT produced significantly greater increases in BMD of the lumbar spine and total body and greater decreases in bone turnover than raloxifene at 12 months.