Abstract
Fluoride strengthens bone, yet makes it more susceptible to fracture. If mechanical factors are important in DJD, an increased risk for DJD in communities where fluoride is consumed is also expected. Hip fractures and knee DJD joint replacements among those >65 years for 1991-1996 were compared between one community with and two without fluoridated water. All cases were assigned to the community where the person lived at the time of the diagnosis. Exclusions included metastatic disease and external cause. For each community, directly standardized age-adjusted rates were calculated using the 1970 US Census as the standard. Standard error (SE) for each rate, relative risks (RRs), and 95% confidence intervals (CI) were calculated. The only age adjusted rate achieving statistical significance was the age-specific rate for hip fracture among women 75-84 years, with a RR = 1.43 (95% CI, 1.02-1.84). The rate of hip fracture among women aged 85+ approached significance with a RR = 1.42 (CI, 0.98 – 1.87). The hip fracture rate among women aged 65-74, however, showed no association and caused the age-adjusted RR to be non-significant. The age-specific rates for hip fracture among men and for knee replacement among both genders showed no trends toward significance. An association between fluoride and DJD was not supported, while a trend in the females for hip fracture was observed.