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 [< or =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.


BACKGROUND
Fluoride is incorporated into bone mineral and has an anabolic effect. However, the biomechanical competence of the newly formed bone may be reduced.


METHODS
A systematic search of PubMed, Embase, and ISI web of science yielded 2,028 references.


RESULTS
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 < or =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.


CONCLUSIONS
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 (< or =20 mg/day of fluoride equivalents) was associated with a significant reduction in fracture risk.
Vestergaard
P
P
The Osteoporosis Clinic, Department of Endocrinology and Metabolism C, Aarhus University Hospital Aarhus Amtssygehus, Tage Hansens Gade 2, 8000 Aarhus C, Denmark. p-vest@post4.tele.dk
Jorgensen
N R
NR
Schwarz
P
P
Mosekilde
L
L
D015519:Bone Density / Q000187:drug effects*; D005459:Fluorides / Q000009:adverse effects / Q000627:therapeutic use*; D050723:Fractures, Bone / Q000503:physiopathology / Q000517:prevention & control*; D006621:Hip Joint / Q000502:physiology; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D016103:Spinal Fractures / Q000517:prevention & control; D013131:Spine / Q000502:physiology
D005459:Fluorides
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