Advertisement

Effects of mandatory salt iodization on breast milk, urinary iodine concentrations, and thyroid hormones: is iodine deficiency still a continuing problem?

  • D. Isiklar Ozberk
  • R. Kutlu
  • I. Kilinc
  • A. O. Kilicaslan
Original Article
  • 82 Downloads

Abstract

Purpose

To investigate whether mandatory use of iodized salt in Turkey, since 1999 has sufficient effects on pregnant women and their newborns’ urinary iodine concentrations (UIC), maternal and newborns’ thyroid function tests and breast milk iodine concentrations (BMIC).

Methods

This cross-sectional analytical-type study was conducted in an obstetrics and gynecology hospital in Konya, Turkey. One hundred and seven pregnant women and their 107 full-term newborns were included into the study. Levels of pregnant women and their newborns’ UIC, thyroid-stimulated hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), thyroglobulin (Tg), and BMIC were studied.

Results

Of 107 women with term pregnancy, mean TSH value and hypothyroidism frequency were found as 2.34 ± 1.33 mIU/L and 18.7%, respectively. Cord blood TSH level was found higher (≥ 10 mIU/L) in five newborns. Accordingly, the incidence of transient congenital hypothyroidism was 4.7% (5/107). Tg levels were observed to be higher in 50.5% of newborns and 22.4% of pregnant women. Frequency of iodized salt use in pregnancies was detected as 96.3% in general population, 97.5% in urban, and 92.9% in rural areas. Of pregnancies and newborns, 57.9 and 53.3% were found to have deficient urinary iodine, respectively, and BMIC deficiency was detected as 52.0%. There was a significant positive correlation between pregnant women’s UIC, and newborns’ UIC and BMIC.

Conclusions

Despite the effective struggle with iodine deficiency and salt iodination control program in Konya, we concluded that iodine deficiency still persists as a significant problem in pregnancies.

Keywords

Breast milk iodine concentration Urinary iodine concentration Newborn Pregnant Thyroid hormones 

Notes

Acknowledgements

We wish to thank the Necmettin Erbakan University Scientific Research Coordination Center (BAP) for the financial support to this study. We also thank to the mothers and their infants for their participation in this study.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflicts of interest.

Ethical approval

This study was planned according to the Helsinki Declaration and was approved by the Ethics Board of Necmettin Erbakan University (approval number: 2013/29).

Informed consent

All pregnant women were informed about the study design, and oral and written informed consent was obtained from all individual participants included in the study.

References

  1. 1.
    Karajewski AD, Burman KD (2011) Thyroid disorders in pregnancy. Endocrinol Metab Clin North Am 40(4):739–763CrossRefGoogle Scholar
  2. 2.
    Zimmermann MB, Jooste PL, Pandav CS (2008) Iodine-deficiency disorders. Lancet 372(9645):1251–1262CrossRefPubMedGoogle Scholar
  3. 3.
    Kurtoglu S, Akcakus M, Kocaoglu E, Gunes T, Budak N, Ataberk ME et al (2004) Iodine status remains critical in mother and infant in Central Anatolia (Kayseri) of Turkey. Eur J Nutr 43:297–303CrossRefPubMedGoogle Scholar
  4. 4.
    Can G, Otken A, Green J (2001) The role of local mass media in promoting the consumption of iodized table salt. Health Educ Res 16(5):603–607CrossRefPubMedGoogle Scholar
  5. 5.
    Yordam N, Ozon A, Alikasifoglu A, Ozgen A, Ceren N, Zafer Y et al (1999) Iodine deficiency in Turkey. Eur J Pediatr 158:501–505CrossRefPubMedGoogle Scholar
  6. 6.
    Pino S, Fang SL, Braverman LE (1998) Ammonium persulfate: a new and safe method for measuring urinary iodine by ammonium persulfate oxidation. Exp Clin Endocrinol Diabetes 106(Suppl 3):22–27Google Scholar
  7. 7.
    Stagnaro-Green A, Abalovich M, Alexander E, Azizi F, Mestman J, Negro R, American Thyroid Association Taskforce on Thyroid Disease During Pregnancy and Postpartum et al (2011) Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid 21:1081–1125CrossRefPubMedPubMedCentralGoogle Scholar
  8. 8.
    Delange F (1998) Screening for congenital hypothyroidism used as an indicator of the degree of iodine deficiency and of its control. Thyroid 8:1185–1192CrossRefPubMedGoogle Scholar
  9. 9.
    Burtis CA, Ashwood ER, Bruns David E. Tietz textbook of clinical chemistry and molecular diagnostics. Edition 5. Elsevier Saunders; 2012Google Scholar
  10. 10.
    Alan HBW. Tietz Laboratory Tests Clinical Guide. Kaya Emerk. Edition 4. Solar Medicine Bookstores; 2011:1046–49Google Scholar
  11. 11.
    Caron P, Hoff M, Bazzi S, Dufor A, Faure G, Ghandour I et al (1997) Urinary iodine excretion during normal pregnancy in healthy women living in the southwest of France: correlation with maternal thyroid parameters. Thyroid 7:749–754CrossRefPubMedGoogle Scholar
  12. 12.
    Delange F, Fisher DA (1995) The thyroid gland. In: Brook CGD (ed) Clinical pediatric endocrinology. Blackwell Sci Ltd, Cambridge, pp 397–433Google Scholar
  13. 13.
    WHO, The United Nations Children’s Fund (UNICEF), ICCIDD. Assessment of iodine deficiency disorders and monitoring their elimination. A guide for programme managers, Edition 3. Geneva, DSÖ 2007Google Scholar
  14. 14.
    Semba RD, Delange F (2001) Iodine in human milk: perspectives for infant health. Nutr Rev 59:269–278CrossRefPubMedGoogle Scholar
  15. 15.
    Bastug O, Korkmaz L, Halis H, Memur S, Korkut S, Ozdemir A et al (2017) Thyroid status of iodine deficient newborn infants living in central region of Turkey: a pilot study. World J Pediatr. 13:479–484CrossRefPubMedGoogle Scholar
  16. 16.
    Iodine Global Network. 2016 statistics at a glance. http://www.ign.org. Accessed 20 Sep 2016
  17. 17.
    Global Iodine Scorecard. [demographic map]. Raleigh: The International Council for Control of Iodine Deficiency Disorders (ICCIDD). 2015. http://www.ign.org/cm_data/Global_map_2014-2015_2.png
  18. 18.
    Azizi F (2007) Iodine nutrition in pregnancy and lactation in Iran. Public Health Nutr. 10(12A):1596–1599CrossRefPubMedGoogle Scholar
  19. 19.
    Oral E, Aydogan Mathyk B, Aydoğan BI, Acıkgoz AS, Erenel H, Acıoglu Celik H et al (2016) Iodine status of pregnant women in a metropolitan city which proved to be an iodine-sufficient area. Is mandatory salt iodisation enough for pregnant women? Gynecol Endocrinol 32(3):188–192CrossRefPubMedGoogle Scholar
  20. 20.
    Leung AM, Pearce EN, Braverman LE (2009) Iodine content of prenatal multivitamins in the United States. N Engl J Med 360:939–940CrossRefPubMedGoogle Scholar
  21. 21.
    Andersson M, Takkouche B, Egli I, Allen HE, de Benoist B (2005) Current global iodine status and progress over the last decade towards the elimination of iodine deficiency. Bull World Health Organ 83(7):518–525PubMedPubMedCentralGoogle Scholar
  22. 22.
    Ordookhani A, Pearce EN, Hedayati M, Mirmiran P, Salimi S, Azizi F et al (2007) Assessment of thyroid function and urinary and breast milk iodine concentrations in ealthy newborns and their mothers in Tehran. Clin Endocrinol (Oxf) 67:175–179CrossRefGoogle Scholar
  23. 23.
    Pearce EN, Leung AM, Blount BC, Bazrafshan HR, He X, Pino S et al (2007) Breast milk iodine and perchlorate concentrations in lactating Boston-area women. J Clin Endocrinol Metab 92(5):1673–1677CrossRefPubMedGoogle Scholar
  24. 24.
    Andersen SL, Møller M, Laurberg P (2014) Iodine concentrations in milk and in urinary during breastfeeding are differently affected by maternal fluid ıntake. Thyroıd 24(4):764–772CrossRefPubMedGoogle Scholar
  25. 25.
    Anaforoğlu İ, Algün E, İnceçayır Ö, Topbaş M, Erdoğan MF (2016) Iodine status among pregnant women after mandatory salt iodisation. Br J Nutr 115(3):405–410CrossRefPubMedGoogle Scholar
  26. 26.
    Kut A, Gursoy A, Senbayram S, Bayraktar N, Budakoglu II, Akgun HS (2010) Iodine intake is still inadequate among pregnant women eight years after mandatory iodination of salt in Turkey. J Endocrinol Invest 33(7):461–464CrossRefPubMedGoogle Scholar
  27. 27.
    Najafi M, Khodaee GH, Bahari M, Sabahi M, Farsi MM, Kiani F (2008) Neonatal thyroid screening in a mild iodine deficiency endemic area in Iran. Indian J Med Sci 62:113–116CrossRefPubMedGoogle Scholar
  28. 28.
    Nohr S, Laurberg P (2000) Opposite variations in maternal and neonatal thyroid function ınduced by ıodine supplementation during pregnancy. J Clin Endocrinol Metab 85(2):623–627PubMedGoogle Scholar
  29. 29.
    Findik RB, Yilmaz G, Celik HT, Yilmaz FM, Hamurcu U, Karakaya J (2014) Effect of povidone iodine on thyroid functions and urine iodine levels in caesarean operations. J Matern Fetal Neonatal Med. 27(10):1020–1022CrossRefPubMedGoogle Scholar

Copyright information

© Italian Society of Endocrinology (SIE) 2018

Authors and Affiliations

  • D. Isiklar Ozberk
    • 1
  • R. Kutlu
    • 2
  • I. Kilinc
    • 3
  • A. O. Kilicaslan
    • 4
  1. 1.Department of Family MedicineGüzelyurt District Government HospitalAksarayTurkey
  2. 2.Department of Family Medicine, Meram Medical FacultyUniversity of Necmettin ErbakanKonyaTurkey
  3. 3.Department of Clinical Biochemistry, Meram Medical FacultyUniversity of Necmettin ErbakanKonyaTurkey
  4. 4.Department of Family MedicineKaratay Fetih Family Health CenterKonyaTurkey

Personalised recommendations