[Effects of long-term fluoride in drinking water on risks of hip fracture of the elderly: an ecologic study based on database of hospitalization episodes].
OBJECTIVE
Fluoridation of drinking water is known to decrease dental caries, particularly in children. However, the effects of fluoridated water on bone over several decades are still in controversy. To assess the risk of hip fracture related to water fluoridation, we evaluated the hip fracture-related hospitalizations of the elderly between a fluoridated city and non-fluoridated cities in Korea.


METHODS
Cheongju as a fluoridated area and Chungju, Chuncheon, Suwon, Wonju as non-fluoridated areas were chosen for the study. We established a database of hip fracture hospitalization episode based on the claims data submitted to the Health Insurance Review Agency from January 1995 to December 2002. The hip fracture hospitalization episodes that satisfied the conditions were those that occurred in patients over 65 years old, the injuries had a hip fracture code (ICD-9 820, ICD-10 S72) and the patients were hospitalized for at least 7days. A total of 80,558 cases of hip fracture hospitalization episodes were analyzed.


RESULTS
The admission rates for hip fracture increased with the age of the men and women in both a fluoridated city and the non-fluoridated cities (p<0.01). The relative risk of hip fracture increased significantly both for men and women as their age increased. However, any difference in the hip fracture admission rates was not consistently observed between the fluoridated city and the nonfluoridated cities.


CONCLUSIONS
We cannot conclude that fluoridation of drinking water increases the risk of hip fracture in the elderly.
Department of Preventive Medicine, Seoul National University College of Medicine & Institute of Environmental Medicine, Seoul, Korea.
Eun Young
EY
Park
Seung Sik
SS
Hwang
Jai Yong
JY
Kim
Soo Hun
SH
Cho
D000368:Aged; D000369:Aged, 80 and over; D002947:Cities; D005260:Female; D005457:Fluoridation / Q000009:adverse effects*; D006620:Hip Fractures / Q000453:epidemiology*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007723:Korea; D008297:Male; D012189:Retrospective Studies; D018570:Risk Assessment