National studies of urinary fluoride status of lebanese school children (aged 6-10) -

Abstract

Fluoride is a trace element; its proper intake and usage is beneficial to bone and tooth integrity. Its level of exposure may decline the prevalence of dental caries, or raise fluorosis cases and influence children’s neurodevelopment. Urinary fluoride excretion is the primary metabolic pathway for fluoride removal from the body and a useful way to estimate the overall fluoride intake of a population. Due to the impracticality of 24-h urinary collection, the F-Cr ratio of a morning spot urine sample was reported to be a good indicator of F excretion. This study is a national cross sectional school-based study that intended to investigate urinary fluoride status of the Lebanese children (aged 6 to 10 years old) by analyzing urine samples of 1350 children. Schools from the 8 Lebanese districts were recruited according to the population load. Subjects were randomly selected from 26 elementary schools. Anthropometric measurements and morning spot urine samples were collected and analyzed for fluoride and creatinine. F-Cr ratio was calculated, and daily fluoride excretion and total daily fluoride intake (TDFI) were estimated. The F-Cr ratio was significantly different between males and females and among age categories, districts and school types. Daily fluoride excretion (mg-d) also varied by age, districts and schools types. The estimated TDFI was for the majority lower than the recommended adequate intake (AI) for this age range (0.05 mg-kg-d of fluoride).TDFI (mg-kg-d) was significantly higher in males than in females. Cultural factors related to eating habits might explain such a difference. TDFI (mg-d) increased significantly with age whereas TDFI (mg-kg-d) did not possibly implying that higher weight with age is correlated to the increasing intake. Students attending public schools and from the Northern district of Lebanon had significantly higher TDFI. These might be respectively influenced by socio-economic and geographical factors. Further research on fluoride intake in Lebanese children is needed to