Health Effects of Ingested Fluoride (1993) / Chapter Skim
Currently Skimming:
3 FLUORIDE EXPOSURE AND RISK OF BONE FRACTURE
3 FLUORIDE EXPOSURE AND RISK OF BONE FRACTURE
Pages 51-72
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 51... ...
Physicians have used fluoride for those purposes for almost 30 years, but until recently, there were no data from systematic, well-controlled clinical trials that addressed the question. Typically, exposure to sodium fluoride in these studies ranged from 50 to 80 mg per day, more than an order of magnitude above the typical exposure to fluoride from fluoridated drinking water.
|
From page 52... ...
Forty-seven percent of the treated group experienced osteoarticular pain and swelling in the lower extremities, attributed to stress fractures, whereas no untreated osteoporotic patients experienced these symptoms. Gastric distress was not observed.
|
From page 53... ...
On bone biopsy, 17% of those treated with sodium fluoride had mineralization defects, whereas none was present in the controls. Population Studies The risk of bone fracture in the elderly has been studied in populations exposed to naturally occurring or adcted fluoride in drinking water and compared with groups exposed to low concentrations of fluoride in drinking water.
|
From page 54... ...
Significantly lower radial bone mass was observed in both younger and older women in the high-fluoride-concentration community. Bone density of the proximal femur was clinically similar in women in the two communities.
|
From page 55... ...
exposure to fluoride from sources other than drinking water, of affected and unaffected members of the population; (2) inability to measure fluoride exposures of study subjects who migrated into study areas before diagnosis of disease or death; and (3)
|
From page 56... ...
counties with natural fluoride concentrations greater than 0.7 mg/L and with rates in 95 counties with naturally low fluoride concentrations (less than 0.4 mg/~) in drinking water.
|
From page 57... ...
More than half of the eligible counties were urban and had natural fluoride concentrations of less than 0.3 mg/~. The proportion of the population receiving fluoridated water in fluoridated counties increased from less than 10% to more than 67% within a
|
From page 58... ...
The criteria for choosing the two nonfluoridated control areas were not presented, nor were hip fracture rates given separately for the two areas. That there might have been important differences between the exposed and nonexposed populations other than fluoridated drinking water is suggested by relative differences in their 1980 and 1987 populations.
|
From page 59... ...
The asymptomatic preclinical stage is characterized by slight increases in bone mass that are cletectable radiographically and bone-ash fluoride concentrations between 3,500 and 5,500 ppm. The typical fluoride concentrations in bone ash from persons who have chronically consumed optimally fluoridated water are less than 1,500 ppm.
|
From page 60... ...
Based on limited data in the literature on skeletal fluorosis, the subcommittee concludes that skeletal fluorosis is not a public health issue in the United States. Discussion Of the six epidemiological studies that used geographic comparisons (where no actual intake data were available)
|
From page 61... ...
BONE FRACTURE IN ANIMALS Studies with laboratory animals designed to determine the effects of fluoride on bone strength or fracture resistance have been done wig several species, a variety of doses and periods of exposure, different stimuli to influence bone growth or resorption, and different measurement techniques. The associated bone fluoride concentrations have been documented in only some of the reports.
|
From page 62... ...
62 .= ,_ Lo 4 Cat En U
|
From page 63... ...
63 t To in: ~ ~>4 3 ~ ~ 3 ~ ~ ~ r ~ ~ at, ~ Ida i u f ~ O O ,3 ~ ~ r C ~,~ ~Z ~ _ O C ~ E: ~E: E: ~ ~c: ~ m ~m All: ~-= O O ~ 8 o O ,,8 O O ~e,)
|
From page 65... ...
After 15-16 weeks, femur strength was measured with the 3-point bending test. In the groups receiving adequate calcium, bone strength was slightly but not significantly lower in the fluoride-treated groups than in the untreated group, and a dose-response relation was not seen.
|
From page 66... ...
drinking water containing fluoride at 0, 5, IS, 30, or 70 mg/L for 16 weeks. The breaking strengths of femurs were determined with a 3-point bending test, and the fluoride concentrations of the second lumbar verte
|
From page 67... ...
between bone fluoride concentration and breaking strength in the 0-, 5-, 15- and 30-mg/L groups. The strength of the regression was not affected significantly by differences in body weight, bone weight, bone length, bone diameter, or cortical thickness.
|
From page 68... ...
The same analyses done on bone samples obtained from dogs were continued in the study to test for "reversibility." This involved feeding a diet enriched in calcium and phosphorus for up to 28 additional weeks. The physical properties of bone were determined with 3- and 4-point bending tests and application of tension.
|
From page 69... ...
(1977) assigned adult male Hartley guinea pigs to four groups that were given distilled drinking water containing fluoride at 0, 2, 10, or 20 mg/~.
|
From page 70... ...
The relation between bone density and fluoride concentration appeared to be inverse, but the trend was not statistically significant. Compressive strength clid not differ among the groups.
|
From page 71... ...
, is a preparative technique that has been shown to be reliable and accurate. The subcommittee concludes that the weight of evidence currently available indicates that bone strength in animals fed a nutritionally adequate diet is not adversely affected unless chronic exposure to fluoride is at least 50 mg/kg in diet or 50 mg/L in water.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.