Page 1 of 1

2017 Urinary Iodine and Fluoride in Lebanese Children - w Comment

Posted: Sat Jul 04, 2020 8:47 pm
by doctorJ
Ghattas H, Francis S, El Mallah C, Shatila D, Merhi K, Hlais S, Zimmermann M, Obeid O - "Lebanese children are iodine deficient and urinary sodium and fluoride excretion are weak positive predictors of urinary iodine" Eur J Nutr 56(2):749-755 (2017)
https://link.springer.com/article/10.10 ... 015-1120-x

NOTE: Since the 1930s has it been shown that iodine and fluoride levels in urine or serum have, in essence, an antagonistic relationship (Kraft 1937a, b; May, 1950; Zhou et al., 2008; Cong, 2012). When iodine intake is high, fluoride may dose-dependently decrease serum iodine levels, and increase urinary iodine levels.

The presumption that fluoride does not interfere with iodine metabolism based on urinary iodine levels is entirely incorrect. Thyroid hormones need to be measured, as well as TSH. Urinary iodine levels from spot urine samples, even at levels below the WHO recommendation, have no significant relationship with thyroid biomarkers TSH, FT3 and FT4 in children and adolescents (Wallborn et al., 2020).

See also: https://poisonfluoride.com/Science/NTP_ ... _data.html

Abstract

Purpose: To assess iodine and fluoride status among Lebanese children.

Methods: A nationally representative cross-sectional study of 6- to 10-year-old schoolchildren was conducted using multistage cluster sampling. Spot urine samples were collected from 1403 children, and urinary iodine, fluoride, creatinine and sodium levels were measured. Salt samples from markets (n = 30) were tested for iodine concentration by titration.

Results: Median urinary iodine concentration was 66.0 µg/l, indicating mild deficiency, and almost 75 % of Lebanese children had a urinary iodine concentration (UIC) <100 µg/l. UIC was higher among children from private schools and in areas of higher socioeconomic status. Most salt samples were fortified at levels far below the legislated requirement, and 56 % of samples contained less than 15 ppm iodine. Fluoride-to-creatinine ratio (F/Cr) was 0.250 (0.159-0.448) mg/g. There were weak positive correlations between UIC and urinary sodium (r 2 = 0.039, P value <0.001) and UIC and urinary fluoride (r 2 = 0.009, P value <0.001).

Conclusions: Lebanese elementary school children are iodine deficient due to inadequately iodized salt. The weak correlation between UIC and urinary sodium suggests most dietary iodine does not come from iodized salt. The poor correlation between UIC and urinary fluoride suggests that fluoride intake is not affecting iodine metabolism. Efforts are needed in Lebanon to improve industry compliance with salt fortification through improved monitoring and enforcement of legislation.

=======================================
Wallborn T, Vogel M, Kneuer A, Thamm M, Dittrich K, Kiess W, Kratzsch J - "Spot urine iodine levels below the WHO recommendation are not related to impaired thyroid function in healthy children and adolescents" Eur J Nutr (2020)
https://pubmed.ncbi.nlm.nih.gov/32390124/

Zhou B, Wang W, Zhuang J - "Correlation analysis of urine iodine and urine fluoride" Mod Prev Med 17 (2008)
http://www.cnki.com.cn/Article/CJFDTOTA ... 817065.htm

Re: 2017 Urinary Iodine and Fluoride in Lebanese Children - w Comment

Posted: Wed Dec 27, 2023 4:57 pm
by wendy
Dr. J, apologies for the late reply. There are numerous concerns around this study. You can't put too much weight on any of the results.

You will notice that data is provided in peculiar ways. Data is grouped by sex, age group, and school type, but no detailed info is given.

For example, data is provided for 972 children age 6 to 8 years old, but how many of them were boys and girls?

That group of children is more than twice the group of 9- to 10-year-olds which is only 423. Again, how many were boys and girls?

How many of the 972, sorted by gender, were in public schools? How many in private schools?

This is all essential information which must be presented, especially in light of the many differences observed.

Creatinine

"UIC was similar between the different age groups (P value = 0.658), while I/Cr ratio decreased with age (P value<0.001)."

The correlation between UIC (µg/l) and urinary fluoride (mg/l) was deemed positive and significant (P value = 0.001; r = 0.090)...however, have you noticed that no UF data in mg/l is presented in Table 2, while data for UIC is presented in both (µg/l) and (µg/g Cr)?