Lebanese children are iodine deficient and urinary sodium and fluoride excretion are weak positive predictors of urinary iodine
- 276 Downloads
To assess iodine and fluoride status among Lebanese children.
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.
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).
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.
KeywordsUrinary iodine excretion Urinary fluoride Iodine/creatinine ratio Fluoride/creatinine ratio Sodium/creatinine ratio Lebanon
This work was funded by the University Research Board (URB) and Iodine Global Network (IGN), and both institutions had no direct or indirect involvements in this project.
Compliance with ethical standards
Integrity of research and reporting
The study protocol was approved by the Institutional Review Board of the American University of Beirut.
Conflict of interest
The authors declare that they have no conflict of interest.
All subjects gave their informed consent prior to their inclusion in the study.
- 2.World Health Organization (2007) Assessment of iodine deficiency disorders and monitoring their elimination: a guide for programme managers. World Health Organization, United Nations Children’s Fund, International Council for Control of Iodine Deficiency definition, GenevaGoogle Scholar
- 3.Aburto N, Abudou M, Candeias V, Wu T, World Health Organization (2014) Effect and safety of salt iodisation to prevent iodine deficiency disorders: a systematic review with meta-analyses. World Health Organization, GenevaGoogle Scholar
- 7.World Health Organization (2004) Iodine status worldwide: WHO global database on iodine deficiency. World Health Organization, GenevaGoogle Scholar
- 8.Cowan J, Najjar S, Sabry Z, Tannous R, Simaan F (1965) Some further observations on goiter in Lebanon. Am J Clin Nutr 17:164–170Google Scholar
- 9.Cowan J, Kassab G, Silahian A, Shadarevian S (1966) Iodine intake and excretion in three different areas of Lebanon. J Med Liban 19:213–223Google Scholar
- 10.Najjar SS, Woodruff CW (1963) Some observations on goiter in Lebanon. Am J Clin Nutr 13:46–54Google Scholar
- 11.Ministry of Public Health of Lebanon (1997) UNICEF. Evaluation studies of the IDD programme in Lebanon. Ministry of Public Health, Beirut (Ref 3222) Google Scholar
- 12.Ministry of Health of Lebanon, UNICEF, WHO, American University of Beirut (1994) IDD survey in Lebanon, 1993-final report. Ministry of Health, Beirut (Ref 485) Google Scholar
- 13.Doumit M, Doughan B (2002) La santé bucco-dentaire des écoliers au Liban. Cahiers d’études et de recherches francophones. Santé 12:223–228Google Scholar
- 14.Ge Y, Ning H, Wang S, Wang J (2005) Comet assay of DNA damage in brain cells of adult rats exposed to high fluoride and low iodine. Fluoride 38:209Google Scholar
- 16.Trivedi M, Verma R, Chinoy N, Patel R, Sathawara N (2007) Effect of high fluoride water on intelligence of school children in India. Fluoride 40:178–183Google Scholar
- 17.El Mallah C, Ghattas H, Shatila D, Francis S, Merhi K, Hlais S, Toufeili I, Obeid O (2015) Urinary magnesium, calcium, and phosphorus to creatinine ratios of healthy elementary school Lebanese children. Biol Trace Elem Res 1–7. doi: 10.1007/s12011-015-0484-3
- 18.Wang G, Zhou R, Wang Z, Shi L, Sun M (1999) Effects of storage and cooking on the iodine content in iodized salt and study on monitoring iodine content in iodized salt. Biomed Environ Sci 12:1–9Google Scholar
- 21.Pardede LV, Hardjowasito W, Gross R, Dillon DH, Totoprajogo OS, Yosoprawoto M, Waskito L, Untoro J (1998) Urinary iodine excretion is the most appropriate outcome indicator for iodine deficiency at field conditions at district level. J Nutr 128:1122–1126Google Scholar
- 22.Andersen S, Karmisholt J, Pedersen KM, Laurberg P (2008) Reliability of studies of iodine intake and recommendations for number of samples in groups and in individuals. Br J Nutr 99:813–818Google Scholar
- 26.Poland PAII (1999) Issues of IDD Newsletter. Young 15(4):105 Google Scholar
- 27.Section UN, Division UP, Communications UDo (2008) Sustainable elimination of iodine deficiency: progress since the 1990 World summit for children. UNICEFGoogle Scholar
- 28.Zimmermann MB, Wegmüller R, Zeder C, Torresani T, Chaouki N (2004) Rapid relapse of thyroid dysfunction and goiter in school-age children after discontinuation of salt iodization. Am J Clin Nutr 79:642–645Google Scholar
- 29.Azizi F, Mehran L, Sheikholeslam R, Ordookhani A, Naghavi M, Hedayati M, Padyab M, Mirmiran P (2008) Sustainability of a well-monitored salt iodization program in Iran: marked reduction in goiter prevalence and eventual normalization of urinary iodine concentrations without alteration in iodine content of salt. J Endocrinol Invest 31:422–431CrossRefGoogle Scholar
- 35.Petersen PE, Baez R, Marthaler T (2014) Basic methods for assessment of renal fluoride excretion in community prevention programmes for oral health. World Health Organization, GenevaGoogle Scholar
- 39.García-Hoyos F, Cardososilva C, Barbería E (2014) Renal excretion of fluoride after fluoride mouth rinses in children. Eur J Paediatr Dent 15:35–38Google Scholar
- 41.Doumit M, Doughan B, Baez R (2004) Oral health programme in Lebanon: technical resistance provided for development of baseline studies for salt fluoridation. Ministry of Public Health, Lebanese University, World Health Organization, BeirutGoogle Scholar
- 42.Hector F, Maria AA, Margaret P, Anthony V, Fatima R-S (2009) Fluoride intake and urinary fluoride excretion in children attending a daycare center in Maracay, Aragua state, Venezuela. J Dent Oral Hyg 1:027–035Google Scholar
- 43.Republic of Lebanon, Ministry of Foreign Affairs (2001) National report on follow-up to the world summit for children. BeirutGoogle Scholar