Effects of treatment with fluoride on bone mineral density and fracture risk - a meta-analysis
Fluoride has fallen into discredit due to the absence of an anti-fracture effect. However, in this meta-analysis, a fracture reducing potential was seen at low fluoride doses [≤20 mg fluoride equivalents (152 mg monofluorophosphate/44 mg sodium fluoride)]: OR = 0.3, 95% CI: 0.1–0.9 for vertebral and OR = 0.5, 95% CI: 0.3–0.8 for non-vertebral fractures.
Fluoride is incorporated into bone mineral and has an anabolic effect. However, the biomechanical competence of the newly formed bone may be reduced.
A systematic search of PubMed, Embase, and ISI web of science yielded 2,028 references.
Twenty-five eligible studies were identified. Spine BMD increased 7.9%, 95% CI: 5.4–10.5%, and hip BMD 2.1%, 95% CI: 0.9–3.4%. A meta-regression showed increasing spine BMD with increasing treatment duration (5.04 ± 2.16%/year of treatment). Overall there was no significant effect on the risk of vertebral (OR = 0.8, 95% CI: 0.5–1.5) or non-vertebral fracture (OR = 0.8, 95% CI: 0.5–1.4). With a daily dose of ≤20 mg fluoride equivalents (152 mg monofluorophosphate/44 mg sodium fluoride), there was a statistically significant reduction in vertebral (OR = 0.3, 95% CI: 0.1–0.9) and non-vertebral (OR = 0.5, 95% CI: 0.3–0.8) fracture risk. With a daily dose >20 mg fluoride equivalents, there was no significant reduction in vertebral (OR = 1.3, 95% CI: 0.8–2.0) and non-vertebral (OR = 1.5, 95% CI: 0.8–2.8) fracture risk.
Fluoride treatment increases spine and hip BMD, depending on treatment duration. Overall there was no effect on hip or spine fracture risk. However, in subgroup analyses a low fluoride dose (≤20 mg/day of fluoride equivalents) was associated with a significant reduction in fracture risk.
KeywordsFluoride Fracture Meta-analysis Meta-regression Monofluorophosphate Sodium fluoride
Research librarian Ms. Edith Clausen is acknowledged for skilful help with the references.
Laura og Jens Veng Christensens Foundation, and Bagermester August H. Jensen og Hustrus Legat provided financial support.
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