Fluoride for the treatment of postmenopausal osteoporotic fractures: A meta-analysis

We conducted an efectiveness meta-analysis to determine the efficacy of flu oride therapy on bone loss, vertebral and nonvertebral fractures and side e ffects in postmenopausal women. A literature search was conducted on MEDLIN E, Current Contents and the Cochrane Controlled Trial Registry. Two indepen dent reviewers selected randomized controlled trials which met predetermine d inclusion criteria. They independently extracted data using predetermined forms and assessed the methodologic quality of the trials using a validate d scale. For dichotomous outcomes, the relative risk (RR) was calculated, a nd for continuous outcomes, the weighted mean difference (WMD) of percentag e change from baseline was calculated. Where heterogeneity existed (determi ned by a chi-square test) a random effects model was used. Eleven studies ( 1429 subjects) met the inclusion criteria. The increase in lumbar spine bon e mineral density (BMD) was found to be higher in the treatment group than in the control group with a WMD 8.1% (95% CI: 7.15, 9.09) after 2 years of treatment and 16.1% (95% CI: 14.65, 17.5) after 4 years. The RR for new ver tebral fractures was not significant at 2 years [0.87 (95% CI: 0.51, 1.46)] or at 4 years [0.9 (95% CI: 0.71, 1.14)]. The RR for new nonvertebral frac tures was not significant at 2 years [1.2 (95% CI: 0.68, 2.10)] but was inc reased at 4 years in the treated group [1.85 (95% CT: 1.36, 2.50)], especia lly if used at high doses and in a non-slow-release form. The RR for gastro intestinal side effects was not significant at 2 years [2.18 (95% CI: 0.86, 1.21)] but was increased at 4 years in the treated group [2.18 (95% CI: 1. 69, 4.57)], especially if fluoride was used at high doses and in a non-slow -release form. The number of withdrawals and dropouts was not different bet ween treated and control groups at 2 and 4 years. Thus, although fluoride h as an ability to increase bone mineral density at the lumbar spine, it does not result in a reduction in vertebral fractures. Increasing the dose of f luoride increases the risk of nonvertebral fractures and gastrointestinal s ide effects without any effect on the vertebral fracture rate.