Iodine nutrition and the prevalence of thyroid disease after salt iodization: a cross-sectional survey in Shanghai, a coastal area in China

Shurong Zou, Fan Wu, Changyi Guo, Jun Song, Cuihua Huang, Zhenni Zhu, Huiting Yu, Yanfei Guo, Xi Lu, Ye Ruan, Shurong Zou, Fan Wu, Changyi Guo, Jun Song, Cuihua Huang, Zhenni Zhu, Huiting Yu, Yanfei Guo, Xi Lu, Ye Ruan

Abstract

Background: Both insufficient and excess iodine may produce thyroid disease. After salt iodization in China, the median urine iodine concentration (UIC) of children aged 8-10 years appeared adequate. However, it is unknown whether dietary changes due to rapid economic development in Shanghai have affected whole population iodine nutrition.

Objective: To assess dietary iodine intake, UIC and the prevalence of thyroid disease in the general population of Shanghai.

Design: A cross-sectional survey was conducted with general participants aged 5-69 years (n = 7,904) plus pregnant and lactating women (n = 380 each) selected by stratified multistage sampling. The iodine concentrations in their salt, drinking water and urine were measured. Daily iodine intake was estimated using the total diet study approach. Serum thyroid hormone concentrations and thyroid-related antibodies were measured and thyroid ultrasonography was performed.

Results: The median iodine concentration in salt was 29.5 mg/kg, and 12.8 µg/L in drinking water. Iodized salt, used by 95.3% of participants, contributed 63.5% of total dietary iodine. Estimated daily iodine intake was 225.96 µg. The median UIC of general participants was 146.7 µg/L; UIC <100 µg/L (iodine insufficiency) was seen in 28.6%; UIC >300 µg/L (iodine excess) in 10.1%. Pregnant women had a median UIC of 135.9 µg/L, with UIC <150 µg/L in 55.4%. Thyroid nodules and subclinical hypothyroidism were found in 27.44% and 9.17%, respectively.

Conclusions: According to published criteria, the current dietary iodine intake in Shanghai was generally sufficient and safe, but insufficient in pregnant women. Thyroid nodules and subclinical hypothyroidism were the commonest thyroid diseases identified.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

References

    1. World Health Organization, United Nations Children’s Fund, and International Council for the Control of Iodine Deficiency Disorders (2007) Assessment of iodine deficiency disorders and monitoring their elimination: A guide for programme managers. Geneva, Switzerland: World Health Organization. 14–16 p.
    1. Chen JX, Li ZZ, Xu HK (1997) China National Iodine Deficiency Disorders Surveillance 1995. Beijing: People’s Medical Publishing House. 16–17 p.
    1. Chen JX, Li ZZ, Xu HK, Hao Y (2000) China National Iodine Deficiency Disorders Surveillance 1997. Beijing: People’s Medical Publishing House. 27–29p.
    1. Chen XY, Li ZZ, Hao Y, Xu HK (2002) China National Iodine Deficiency Disorders Surveillance 1999. Beijing: People’s Medical Publishing House. 39–41p.
    1. Chen XY, Sun DJ, Liu SJ (2003) China National Iodine Deficiency Disorders Surveillance 2002. Beijing: People’s Medical Publishing House. 55–57 p.
    1. Xiao DL, Sun DJ, Bai HQ, Liu SJ (2007) China National Iodine Deficiency Disorders Surveillance 2005. Beijing: People’s Medical Publishing House. 43–46p.
    1. Yan YQ (2003) A survey on iodine nutrition in 5 groups of target population in China. Chinese Journal of Endemiology 22: 141.
    1. Yang F, Teng WP, Shan ZY, Wang ZY, Jin Y, et al. (2001) A comparative epidemiologic survey of hyperthyroidism in areas with different iodine intake. Chinese Journal of Endocrinology and Metabolism 17: 197–201.
    1. Liao EY, Chao CS (2001) Endocrinology. Beijing: People’s Medical Publishing House. 619 p.
    1. Shan ZY, Teng WP, Li YS, Wang ZY, Jin Y, et al. (2001) Comparative epidemiologic study on the prevalence of iodine-induced hypothyroidism. Chinese Journal of Endocrinology and Metabolism 17: 71–74.
    1. Li QS (2009) Ultrasound of Superficial Organs (Series of Ultrasound Physician Training). Beijing: People’s Military Medical Press. 61–77 p.
    1. Helsel DR (1990) Less than obvious-statistical treatment of data below the detection limit. Environ Sci Technol 24: 1766–1774.
    1. United States Environmental Protection Agency (2006) Data Quality Assessment: Statistical Methods for Practitioners. EPA website. Available: . Accessed 2012 Jun 20th.
    1. World Health Organization (2004a) Vitamin and mineral requirements in human nutrition. Geneva, Switzerland: World Health Organization. 303–317 p.
    1. Chinese Nutrition Society (2000) Chinese Dietary Reference Intakes. Beijing: China Light Industry Press. 193p.
    1. World Health Organization, International Classification for Patient Safety (2009) Iodine and inorganic iodides: Human health aspects. Concise International Chemical Assessment Document 72. Geneva, Switzerland: World Health Organization. 5–31 p.
    1. World Health Organization, United Nations Children’s Fund, and International Council for the Control of Iodine Deficiency Disorders (2007) Assessment of iodine deficiency disorders and monitoring their elimination: A guide for programme managers. Geneva, Switzerland: World Health Organization. 32–34p.
    1. Travers CA, Guttikonda K, Norton CA, Lewis PR, Mollart LJ, et al. (2006) Iodine status in pregnant women and their newborns: are our babies at risk of iodine deficiency? Med J Aust 184: 617–620.
    1. Bonet-Manso MP, Atiénzar-Martínez MB, Fuentes-Gómez MI, Plaza-Vicente C (2007) Iodine levels and intake in a population of healthy pregnant women. Enferm Clin 17: 293–300.
    1. Caldwell KL, Makhmudov A, Ely E, Jones RL, Wang RY (2011) Iodine status of the U.S. population, National Health and Nutrition Examination Survey, 2005–2006 and 2007–2008. Thyroid 21: 419–427.
    1. Gharib H (1997) Changing concepts in the diagnosis and management of thyroid nodules. Endocrinol Metab Clin North Am 26: 777–800.
    1. Leech JV, Smith LW, Clute HM (1928) Aberrant thyroid glands. Am J Pathol 4: 481–492.
    1. Rojeski MT, Gharib H (1985) Nodular thyroid disease: evaluation and management. N Engl J Med 313: 428–436.
    1. Tunbridge WM, Evered DC, Hall R, Appleton D, Brewis M, et al. (1977) The spectrum of thyroid disease in a community: the Whickham survey. Clin Endocrinol 7: 481–493.
    1. Vander JB, Gaston EA, Dawber TR (1968) The significance of nontoxic thyroid nodules: final report of a 15-year study of the incidence of thyroid malignancy. Ann Intern Med 69: 537–540.
    1. Brander A, Viikinkoski P, Nickels J, Kivisaari L (1991) Thyroid gland: US screening in a random adult population. Radiology 181: 683–687.
    1. Matovinovic J, Hayner NS, Epstein FH, Kjelsberg MO (1965) Goiter and other thyroid diseases in Tecumseh, Michigan: studies in a total community. JAMA192: 234–240.
    1. Rallison ML, Dobyns BM, Keating Jr FR, Rall JE, Tyler FH (1975) Thyroid nodularity in children. JAMA 233: 1069–1072.
    1. Trowbridge FL, Matovinovic J, McLaren GD, Nichaman MZ (1975) Iodine and goiter in children. Pediatrics 56: 82–90.
    1. Bruneton JN, Balu-Maestro C, Marcy PY, Melia P, Mourou MY (1994) Very high frequency (13 MHz) ultrasonographic examination of the normal neck: detection of normal lymph nodes and thyroid nodules. J Ultrasound Med 13: 87–90.
    1. Woestyn J, Afschrift M, Schelstraete K, Vermeulen A (1985) Demonstration of nodules in the normal thyroid by echography. Br J Radiol 58: 1179–1182.
    1. Hull OH (1955) Critical analysis of two hundred twenty-one thyroid glands: study of thyroid glands obtained at necropsy in Colorado. AMA Arch Pathol 59: 291–311.
    1. Mortensen JD, Woolner LB, Bennett WA (1955) Gross and microscopic findings in clinically normal thyroid glands. J Clin Endocrinol Metab 15: 1270–1280.
    1. Oertel JE, Klinck GH (1965) Structural changes in the thyroid glands of healthy young men. The Med Ann Dist Columbia 34: 75–77.
    1. Dunn JT (1998) What’s happening to our iodine? J Clin Endocrinol Metab 83: 3398–3400.
    1. Canaris GJ, Monowitz NR, Mayor G, Ridgway EC (2000) The Colorado thyroid disease prevalence study. Arch Intern Med 160: 506–34.
    1. Hollowell JG, Staehling NW, Flanders WD, Hannon WH, Gunter EW, et al. (2001) Serum TSH, T4 and thyroid antibodies in the United State population (1998 to 1994): National Health and Nutrition Examination Survey (NHANES III). J Clin Endocrine Metab 87: 489–499.
    1. Teng WP (2003) Subclinical hypothyroidism. Foreign Medical Sciences Section of Endocrine 23: 370–372.

Source: PubMed

スポンサーと協力者

医学的状態

薬物療法

3
購読する