Indian Pediatrics 1999; 36:178-180 

Assessment of Iodine Deficiency in Ernakulam District, Kerala State

Iodine is one of the essential microelements required for normal human growth and development. Deficiency of iodine in the diet may result in development of goiter and other iodine deficiency disorders (IDD) including physical and mental retardation and endemic cretinism. A survey conducted in the year 1984 in Ernakulam district reported a goiter prevalence of 44.47%(1). Recently, WHO/ UNICEF/ICCIDD have recommended that for assessing iodine deficiency in an area, children in the age group of 6-12 years should. be surveyed because of their combined high vulnerability and r~presentativeness(2). The present pilot study was conducted in the year 1998 to assess the status of iodine deficiency in the Ernakulam district.

Subjects and Methods

The study was conducted in Ernakulam district, Kerala. School children in 6-12 years of age were selected. The Ernakulam district has a total population of 27,97,779(3). The expected total population of children in 6-12 years was 2,51,793 (with the birth rate being. 15 per thousand population). The sample size
. for the study comprised 0.5% of total children in the age group of 6-12 years. In the district, six schools were randomly selected and a total of 1254 children in the age group of 6-12 years, who attended the primary school On the day of the survey, were studied. In each class, children were assembled and briefed about the IDD survey activities. All the children were clinically examined for goiter using the palpation method, by the first author. Goiter size was graded according to the criteria recommended by the WHO/UNICEF/ICCIDD(2). The sum of grades I and II goiter provided the total goitre prevalence in the study population.

Autoseal polyethylene pouches were given to every sixth child and they were requested to bring 20 g of salt which was routinely consumed by their family. A total of 191 salt samples were collected. The iodine content of the salt samples was analyzed using the standard iodometrictitration method(4).

Casual urine samples were collected from 220 children every sixth child from those clinically examined. Plastic bottles with screw caps were used to collectable urine samples. The samples were stored in the refrigerator at 40 C until analysis. The Urinary Iodine Excretion (UIE) level was analyzed by standard laboratory method(5).

Results

A total of 1254 school children in the age group. of 6-12 years were included in the study. Only 1 % of the children had goiter. Thirteen children had grade I goiter: none had grade II goiter.

One hundred ninety one salt samples were collected from the families of school children. About 94.2% were of powdered salt while 5.8% were of 'crystalline salt. Assessment of iodine content in the salt samples revealed that °!1ly 2.6% salt samples had nil and 8.4% had less than 15 ppm of iodine. The majority (89%) of the salt samples had iodine content of 15 ppm and more.

Out of 220 urine samples, the proportion of children with <2 mcg/dl, 2-4.9 mcg/dl, 5-9.9 mcg/dl and 10mcg/dl and more UIE levels were 0.9, 1.4, 8.2, and 89.5%, respectively. The median UIE level was 20 mcg/dl.

Discussion

According to WHO/UNICEF/ICCIDD, if more than 5% of the school age children (6-12 yr) have goiter then the area should be classified as endemic for iodine deficiency(2). In the present study, the goiter prevalence in school children was found to be 1 %.

WHO/UNICEF/ICCIDD have also recommended that no iodine deficiency is indicated in a population when median UIE level is.1O mcg/dl, i.e., more than 50% of the urine I samples have UIE level of 10 mcg/dl, and not more than 20% of samples have UIE level of 5 mcg/dl(6). The' median UIE level in the present study was found to be 20 mcg/dl. Goiter prevalence is indicative of past iodine status while UIE levels indicate the present iodine status of the population. In the present study, both the indicators were negative, indicating no iodine deficiency.

It was found that 89% of the subjects were consuming iodized salt with adequate quantity of iodine. This could be the possible reason for adequate iodine nutriture in the population studied. Also, Ernakulam being a coastal district, the study population mainly . consumed sea foods which have high iodine content. Earlier studies conducted in the coastal regions of India,. Pondicherry and Portblair, have reported low prevalence of goiter in school children - 2.6% and 9.5%, respectively(6,7). However studies from Panaji and Bombay have reported high goiter prevalence rate of 16.6% and 43% respectively(8,9). These studies have postulated that iodine deficiency could possibly be due to goitrogens in the food consumed by the coastal population.

The findings of the present pilot study revealed that iodine deficiency was not a public health problem in Ernakulam district.

Acknolwledgements

The authors are grateful to the school principals and students for their kind cooperation in the data collection and would also like to thank the Director, All India Institute of Medical Sciences for encouraging us in pursuing the academic and research activities.

 

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