EFFECTS OF CYCLICAL ETIDRONATE THERAPY ON BONE LOSS IN EARLY POSTMENOPAUSAL WOMEN WHO ARE NOT UNDERGOING HORMONAL REPLACEMENT THERAPY

This study was carried out to investigate the effectiveness and tolera bility of cyclical etidronate therapy in the prevention of bone loss o ccurring in early postmenopausal women who are not undergoing hormone replacement therapy (HRT). A total of 109 Caucasian women aged 45-60 y ears were treated with etidronate 400 mg/day or placebo for 14 days fo llowed by calcium supplementation 500 mg/day for 77 days. Ninety-one w omen completed the 2 years of the study. After 2 years, the estimated difference between the two groups as regards lumbar spine bone mineral density (BMD) was 2.53% (SEM 1.07%; p = 0.01); BMD of the hip and wri st were not significantly different between treatment groups. A clear reduction in bone turnover was obtained as evidenced by a significant decrease in serum alkaline phosphatase level and in urinary N-telopept ide/creatinine ratio in the etidronate group; the difference between t he two groups was -12% +/- 3.2% for serum alkaline phosphatase level ( p = 0.019) and -22.9% +/- 13.7% for the urinary N-telopeptide/creatini ne ratio (p=0.047). There was no statistically significant difference between the two groups in terms of the serum osteocalcin levels and ur inary hydroxyproline/creatinine and calcium/creatinine ratios. Etidron ate was generally well tolerated and its adverse event profile was sim ilar to that of placebo. The results of this study indicate that cycli c etidronate therapy can prevent trabecular bone loss, with no deleter ious effect on cortical bone, in the first 5 years of menopause and th at it has a very high safety margin.