Endemic goiter in Sri Lanka

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OBJECTIVES

1. What is endemic goitre?2. Indications used to identify.3. Gravity of the problem4. How does it occur?5. Remedies 6. Earlier situation in Srilanka -before 19957. Universal Salt Iodination programme-19958. Modern situation in Srilanka -after 19959. Malpractices10. Conclusions

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1. What is endemic goitre?

• When a significant proportion of the population (over 10 %) of any region, has palpable or obviously enlarged thyroids, the condition is termed as endemic goitre.

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What is endemic goitre? (continued..)

• An area is considered goitrous when 5% of the girls aged 12 – 14 show clinical signs of goitre

• Endemic goiter is formed in regions where the Iodine intake is less than 50 μg per day.

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2. Indications used to identify endemic goitre.

• The median urinary iodine(UI) level in the population ideally should be between 100 – 200 μg/L

• Palpation of the thyroid gland by trained medical personnel to assess the size and shape of the gland.

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3. Gravity of the problem• Affects over one billion people worldwide.

• 172 million people in the south east Asia region have goitre. Further 599 million are at risk.

• One of most common causes of Multi Nodular Goitre globally.

• Hypothyroidism in pregnant women can have serious adverse effects on the fetus.

• Impairs genetic potential of individuals and collectively undermines the capacity of people to contribute to the development of the country.

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4. How does it occur?Low iodine intake

Low Thyroid hormone production

The Pituitary gland secrete greater quantities of TSH

in an attempt to restore Thyroid hormones

Tropic action of TSH on gland Gland enlarges

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How does Iodine deficiency occur?

• Reduced iodine intake ( food and water)1. Affects people in some geographical areas

ie; Mountains- central division River basin- kelani river, kalu river

2. Hard water consumption-Ca decrease metabolic effect of thyroxin

3. Goitrogens – cabbage, manioc(SCN ), ˉ nitrates(fertilizers)

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5. Remedies

Either of the following could be done as a precaution to avoid getting goitre..

• Enrichment of a common food. ie: Salt• Provision of tablets of NaI or KI.

• Most common remedy is fortifying table salt with iodine.

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6. Earlier to 1995 in Srilanka

• The 1st of the goitre studies made in srilanka was in 1947-49

• Results suggested the existence of an endemic area for iodine deficiency (goitre belt) in srilanka.

• It was confined to the south-west region of the country including western, central and southern provinces.

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• In other words goitre was prevalent, in the wet zone – high annual rain fall due to heavy monsoon rains .

• high annual rain fall was believed to leach soil iodine deficiency

• However, they reported that endemic goitre was not associated with cretinism to any greater extent. Ie; it was mild iodine deficiency

• But recent surveys have found endemic goitre in dry zone too.

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Earlier to 1995 in Srilanka (continued..)

• A survey done in 1989 revealed that,overall prevalence rate of goitre was 18.8% Of which 23.2% - girls and 14.0% - boys.

• Prevalence in districts varied from, 6.5% in Matale to 30.2% in Kalutara

• It was higher in rural than urban areas, and in inland than coastal areas.

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7. Universal Salt Iodination programme-1995

• In view of these findings and parallel to the Universal Salt Iodination programme(USI), iodization of salt becoming mandatory following an enactment by the government in 1995.

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Universal Salt Iodination programme-1995(continued..)

• Require an iodine content of 50ppm at the factory and 25ppm at the consumer level.

• Salt iodination is now used as a simple , cost effective way to prevent iodine deficiency.

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8. Modern situation in Srilanka -after 1995

• The total goiter prevalence was reduced in some districts in significant levels according to the UI levels.

• Nevertheless it was less than expected progress.

• A research done in 2001 indicated an overall prevalence of the goitre rate was 20.9%

• Although Western and Southern province goitre rates were decreased , there was a marginal in crease in Uwa and Central provinces.

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Goitre prevalance – 2001

western southern uwa north central

central overall0

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10

15

20

25

30

16.3 17.1

26 26.224.3

20.9

Total Goitre Rate %

Modern situation in Srilanka -after 1995(continued..)

• Remarkably in the north central province(NCP) indicated more than adequate levels of urine iodine , while the total goitre rate in the NCP was among the highest in Srilanka.

• Authorities still research on this to identify whether it is the Wolff-Chaikoff effect or presence of multiple goitrogens is causing this phenomenon.

• Selenium deficiency in the soil is also thought to be associated with goitre prevalence.

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9. Malpractices

• Even the Iodine content of the iodinated salt can get lowered due to poorly monitored processes in manufacturing, transporting and storing them.

• It is important to add iodized salt after cooking process as iodine could easily get destroyed by excessive heat.

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10.Conclusions

• Srilanka has achieved satisfactory iodine status as indicated by the UI levels.145.3 μg/L

• It’s important to develop a surveillance system to monitor salt iodine content.

• People should be advised properly about the goitrogens and proper use of iodinated salt.

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References:

World health organization (WHO) website: www.who.int Nutrition throughout life cycle: Prof. T.W. Wickramanayake

• Ganong’s review of medical physiology.

• Research articles.

Group members

• 107 - D.L. Manjula Prasad• 108 - L.G. Jeewana Prasad• 109 - D.W. Premakeerthi• 110 - T.E. Premasiri

Acknowledgment

• We would like to thank Dr. Eric De Zoysa for guiding us and for the valuable support towards making this attempt a success.

THANK YOU!