Comparison of the effects of three oral bisphosphonate therapies on the peripheral skeleton in postmenopausal osteoporosis: the TRIO study

Summary

We compared the effects of oral alendronate, ibandronate and risedronate on the central and peripheral skeleton over 2 years. We report differences in effect on the central skeleton but not on the peripheral skeleton. Greater effects were observed for ibandronate (and alendronate) than risedronate at the spine but not the hip.

Introduction

Generally, comparative clinical trials of bisphosphonates have examined changes in bone within central skeletal regions. We have examined the effects of bisphosphonate treatment on the peripheral skeleton.

Methods

We conducted a 2-year, open-label, parallel randomised control trial of three orally administered bisphosphonates, at their licensed dose, to examine and compare their effects on the peripheral skeleton using multiple modes of measurement. We studied 172 postmenopausal women (53–84 years) who had either a bone mineral density (BMD) T-score of? ≤??2.5 at the spine and/or total hip or ?Premenopausal women (33–40 years, n?=?226) were studied to monitor device stability.

Results

We measured central BMD of the lumbar spine, total hip, total body and forearm using dual-energy X-ray absorptiometry. We measured calcaneus BMD (using dual-energy X-ray absorptiometry plus laser), radius and tibia BMD (using peripheral quantitative computed tomography), finger BMD (using radiographic absorptiometry), and phalangeal and calcaneal ultrasound variables (using quantitative ultrasound). Mixed effects regression models were used to evaluate effects of time and treatment allocation on BMD change. By 2 years, there were significant increases (p?Conclusions The increases in lumbar spine and total body BMD were greater with ibandronate and alendronate than with risedronate. Treatment effects on peripheral measurements did not differ between the three bisphosphonates.