Urinary iodine excretion and thyroid function status in school age children of hilly and plain regions of Eastern Nepal

BMC Research Notes

Nirmal Baral¹  Gauri Shankar Sah⁴  David A. Brodie⁵  Ashwini Kumar Nepal¹  Paras Kumar Pokharel²  Madhab Lamsal¹  Binod Kumar Lal Das¹  Basanta Gelal¹  Prem Raj Shakya³ 

[1] Department of Biochemistry, B.P. Koirala Institute of Health Sciences, Dharan, Nepal;Department of Community Medicine, B.P. Koirala Institute of Health Sciences, Dharan, Nepal;Department of Biochemistry, School of Medicine, Patan Academy of Health Sciences, Lagankhel-5, Lalitpur, Nepal;Department of Paediatrics and Adolescent Medicine, B.P. Koirala Institute of Health Sciences, Dharan, Nepal;Department of Biochemistry, Faculty of Society and Health, Bucks New University, High Wycombe, Buckinghamshire, UK

关键词: Nepal;    Thyroid function;    Thyroglobulin;    Iodized salt;    Iodine status;   

Others  :  1230465
DOI  :  10.1186/s13104-015-1359-6

 received in 2014-02-14, accepted in 2015-08-17,  发布年份 2015

【 摘 要 】

Background

Iodine deficiency is a major public health problem in many developing countries including Nepal. The present study was designed to investigate the urinary iodine excretion (UIE), thyroid function status and household salt iodine content (SIC) in school-aged children (SAC) and to establish the relationships between these factors.

Methods

A community-based cross sectional study was conducted in selected schools of two districts, Tehrathum and Morang, lying in the hill and plain region of eastern Nepal respectively. A total of 640 SAC, (Tehrathum n = 274 and Morang n = 366) aged 6–11 years, were assessed for UIE and household SIC. Among the 640 children, 155 consented to blood samples (Tehrathum n = 78 and Morang n = 77) to test for serum thyroglobulin (Tg), thyroid stimulating hormone (TSH), free triiodothyronine (fT ₃ ) and free thyroxine (fT ₄ ). UIE was measured by ammonium persulfate digestion method. SIC was measured by iodometric titration method and Tg, TSH, fT ₄and fT ₃were measured by immunoassay based kit method.

Results

In Tehrathum and Morang, 9.5 and 7.7 % of SAC had UIE values of UIE <100 µg/L while 59.5 and 41 % had iodine nutrition values of >299 µg/L, with median UIE of 345.65 and 270.36 µg/L respectively. The overall medians were as follows, Tg 14.29 µg/L, fT ₃3.94 pmol/L, fT ₄16.25 pmol/L and TSH 3.61 mIU/L. There was a negative correlation between UIE and Tg (r = −0.236, p = 0.003) and a positive correlation between UIE and SIC (r = 0.349, p < 0.0001). We found 19.5 %, n = 15 and 16.7 %, n = 13 subclinical hypothyroid cases in Morang and Tehrathum respectively. Iodometric titration showed only 6.4% (n = 41) of the samples had household SIC <15 ppm. Multivariate analysis revealed that use of packaged salt by SAC of Tehrathum district correlated with higher UIE values.

Conclusions

Our focused data suggests that collaborative universal salt iodization (USI) programs are improving the health of children in the Tehrathum and Morang districts of Nepal. We also found that excessive iodine in a large portion of the study groups is a substantial concern and iodine intervention programs need to deal with both deficient and excessive iodine scenarios that can both be present simultaneously in study populations.

【 授权许可】

   
2015 Shakya et al.

【 图 表 】

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