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

Shakya PR, Gelal B, Das BK, Lamsal M, Pokharel PK, Nepal AK, Brodie DA, Sah GS, Baral N - BMC Res Notes (2015)

Bottom Line: We found 19.5%, n = 15 and 16.7%, n = 13 subclinical hypothyroid cases in Morang and Tehrathum respectively.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, School of Medicine, Patan Academy of Health Sciences, Lagankhel-5, PO Box: 26500, Lalitpur, Nepal. premshakya@pahs.edu.np.

ABSTRACT

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 (fT3) and free thyroxine (fT4). UIE was measured by ammonium persulfate digestion method. SIC was measured by iodometric titration method and Tg, TSH, fT4 and fT3 were 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, fT3 3.94 pmol/L, fT4 16.25 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.

No MeSH data available.


Related in: MedlinePlus

Percent distribution of salt iodine concentrations in primary school children in the Tehrathum and Morang districts
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Fig4: Percent distribution of salt iodine concentrations in primary school children in the Tehrathum and Morang districts

Mentions: Interestingly, the UIE in 90.3 % of our population was higher than the WHO cut off point (100 µg/L) and is cause for concern because excessive iodine intake can be detrimental to health. Our study also showed interesting findings with almost 50 % having excessive UIE, though salt sample from their respective homes showed iodine concentrations within desired limits, with only approximately 7 % showing more than 60 ppm (See Fig. 4). This is of concern because elevated iodine can lead to induced hyperthyroidism and autoimmune thyroid disease. It is a challenging scenario to consider that the serious consequences of ID can coexist with those of excessive iodine. One potential source of high iodine values may be due to the eating habits of this particular population with frequent consumption of high-iodine uncooked instant noodles and flavor sachets in their lunch break. The high values for those using packaged salt are surprising. They exceed the levels of 15–40 ppm recommended by the WHO. One explanation is that when packaged salt, which is produced at a level of 50 ppm, is transported and stored, it then retains a much higher iodine level than originally anticipated. We observed this in our study, something that was similarly noted in a study undertaken in the Khumbu region of Nepal by Heydon et al. [34]. This illustrates further how regular sampling of iodine status and basic education about nutritional supplements are necessary so that the appropriate action taken to increase or decrease iodine intake.Fig. 4


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

Shakya PR, Gelal B, Das BK, Lamsal M, Pokharel PK, Nepal AK, Brodie DA, Sah GS, Baral N - BMC Res Notes (2015)

Percent distribution of salt iodine concentrations in primary school children in the Tehrathum and Morang districts
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4548539&req=5

Fig4: Percent distribution of salt iodine concentrations in primary school children in the Tehrathum and Morang districts
Mentions: Interestingly, the UIE in 90.3 % of our population was higher than the WHO cut off point (100 µg/L) and is cause for concern because excessive iodine intake can be detrimental to health. Our study also showed interesting findings with almost 50 % having excessive UIE, though salt sample from their respective homes showed iodine concentrations within desired limits, with only approximately 7 % showing more than 60 ppm (See Fig. 4). This is of concern because elevated iodine can lead to induced hyperthyroidism and autoimmune thyroid disease. It is a challenging scenario to consider that the serious consequences of ID can coexist with those of excessive iodine. One potential source of high iodine values may be due to the eating habits of this particular population with frequent consumption of high-iodine uncooked instant noodles and flavor sachets in their lunch break. The high values for those using packaged salt are surprising. They exceed the levels of 15–40 ppm recommended by the WHO. One explanation is that when packaged salt, which is produced at a level of 50 ppm, is transported and stored, it then retains a much higher iodine level than originally anticipated. We observed this in our study, something that was similarly noted in a study undertaken in the Khumbu region of Nepal by Heydon et al. [34]. This illustrates further how regular sampling of iodine status and basic education about nutritional supplements are necessary so that the appropriate action taken to increase or decrease iodine intake.Fig. 4

Bottom Line: We found 19.5%, n = 15 and 16.7%, n = 13 subclinical hypothyroid cases in Morang and Tehrathum respectively.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, School of Medicine, Patan Academy of Health Sciences, Lagankhel-5, PO Box: 26500, Lalitpur, Nepal. premshakya@pahs.edu.np.

ABSTRACT

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 (fT3) and free thyroxine (fT4). UIE was measured by ammonium persulfate digestion method. SIC was measured by iodometric titration method and Tg, TSH, fT4 and fT3 were 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, fT3 3.94 pmol/L, fT4 16.25 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.

No MeSH data available.


Related in: MedlinePlus