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Indian Pediatr 2013;50: 587-589 |
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Iodine Deficiency Disorder in Children Aged
6-12 Years of Ambala, Haryana
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C Chaudhary, R Pathak, SK Ahluwalia, RKD Goel and S Devgan
From Department of Community Medicine, Maharishi
Markandeshwar Institute of Medical Sciences and Research (MMIMSR),
Mullana (Ambala), Haryana, India.
Correspondence to: Dr Chintu Chaudhary,
Resident, Department of Community Medicine, D-72, Sector-9,
New Vijay Nagar, Ghaziabad 201 009, Uttar Pradesh, India.
Email:
[email protected]
Received: June 13, 2012;
Initial review: July 07, 2012;
Accepted: October 25, 2012.
PII: S097475591200499
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We conducted this study to assess the prevalence of goitre among 2700
children (6-12 yr) of district Ambala in Haryana. Children were examined
as per standards laid by National iodine deficiency disorder control
programme (NIDDCP). Multi stage cluster sampling method was used. Urine
and salt samples were also studied for iodine concentration. The
overall prevalence of goitre in the studied subjects was 12.6%. The
median urinary iodine excretion in the study sample was more than
100µg/L Iodine content was found to be adequate in 88% of salt samples.
We conclude that there was a high prevalence of goitre in young children
despite iodine repletion. This calls for identification of factors to
strengthen NIDDCP and the need to emphasize use of iodized salt in
Haryana.
Key words: Goitre, IDD, Urinary Iodine
excretion.
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National Iodine Deficiency
Disorders Control Program was launched in India in 1962. But after 44
years of the implementation of the program, a recent nationwide survey
revealed that out of 324 districts surveyed, 263 districts were still
endemic for iodine deficiency disorders (IDD) with prevalence more than
10 % [1]. We conducted this study to assess the prevalence of iodine
deficiency disorders in children aged between 6-12 years in district
Ambala, to assess the level of iodine in salt samples at household
level; and to determine median urine iodine concentration in a sample of
children.
Methods
The present study was conducted in 6-12 years old
children from November 2010 to October 2011. Multi-stage cluster
sampling methodology was adopted for selecting the study population. A
list of all the schools in Ambala district was procured from the office
of District Education Officer and a cumulative population was
calculated. It came out to be 81,525. As per data available from census
2001 there were 1,09056 children in the age group of 6-12 years in the
district under study. Thus, the school enrolment rate of the 6-12 years
old children in Ambala district came out to be 74.6%. So, for
proportionate representation, 75% (2050) of the total study population
was taken from the school and 25% (650) from community representing the
out of school children. Those children were screened for goitre by
standard palpation method and were graded according to the criteria
recommended by the joint WHO/UNICEF/ICCIDD.
Consents were taken from the school authorities of
Ambala, principals of each school surveyed, and the parents of the
children whose urine samples were taken. Ethical clearance was also
sought from Institutional ethical committee before conducting the study.
Salt Samples: As per NIDDCP guidelines during the
survey, 540 (1/5 th of the
total sample size) salt samples were collected from the houses of
children. Approximately 20 grams of salt were collected in auto seal
plastic pouches and were tested qualitatively on spot with MBI kit and
iodine concentration was recorded as 0, <15, >15 ppm [2].
Urine Samples: As per NIDDCP guidelines during
the survey, 270 (half of the salt sample size) urine samples i.e.
9 samples of urine per cluster were obtained from 6-12 years old
children for iodine estimation, maintaining equal ratio for both
genders. Those samples were collected in labelled plastic bottles (50 mL
capacity with screw cap and thymol crystal as preservative) and taken to
the IDD cell Karnal, for quantitative estimation of iodine in urine. The
iodine content of urine was estimated by iodometric titration.
Statistical analysis: Data processing and
analysis was done by using SPSS version 17.0. Number and percentages
were calculated for categorical data. Chi-Square test was applied.
Median urinary iodine excretion was calculated.
Results
Two thousand and seven hundred children from six to
twelve years were clinically examined for the presence of goitre during
survey. Of these, 53% were males and 47% were females. The mean age of
the children vary between 8.88 ± 1.83 years. Prevalence of goitre
increased with that of age. The highest prevalence (%) was observed in
the age group of 11-12 years. Overall goitre prevalence rate was 12.6%.
Prevalence was significantly higher among females than males (P=.0003)
(Table I). Age-specific prevalence rate (ASPR) was higher
in 9 to 12 yr age group as compared to 6 to 8 yr age group. No case of
nodular goitre was observed (Table I).
TABLE I Age and Sex-wise Prevalence of Goiter Among Study Subjects (N=2700)
|
Age in years
|
Total No.(%) |
|
6-8 years No. (%) |
9-10 years No. (%) |
11-12 years No. (%) |
|
Goitre grades |
Female |
Male |
Female |
Male
|
Female |
Male
|
|
Grade 0 |
557 (20.6) |
580 (21.5) |
296 (10.9) |
348 (12.9) |
223 (8.3) |
356 (13.2) |
2360 (87.4) |
Grade I |
42 (1.5) |
38 (1.4) |
48 (1.8) |
32 (1.2) |
67 (2.5) |
44 (1.6) |
271 (10) |
Grade II |
14 (0.5) |
11 (0.4) |
13 (0.5) |
9 (0.3) |
10 (0.4) |
12 (0.4) |
69 (2.6) |
Total |
613 (22.7) |
629 (23.3) |
357 (13.2) |
389 (14.4) |
300 (11.1) |
412 (15.2) |
2700 (100) |
Chi square– 16.09, p- value - 0.0003 |
In our study, since there was no child with UIE of <
20 µg/L, we used a modified classification as follows: <50 µg/L was
labelled as moderate deficiency, 50-100 µg/L as mild deficiency and >100
µg/ L as adequate iodine intake. Median iodine concentration of >100
µg/L defines a population with no iodine deficiency, i.e. at
least 50 per cent of the samples should be above 100 µg/L according to
the epidemiological criteria for assessing iodine nutrition based on
median urinary iodine concentration in children. Median iodine
concentration of the study population was more than 100 µg/L.
Overall, 8.5% salt samples examined at consumer level
by spot kit showed some iodization, majority (88%) were adequately
iodised, i.e. having >15 ppm, while 3.2% were non-iodised (Table
II).
TABLE II Level of Urinary Iodine Excretion and Iodine Content of Salt Samples
Level of urinary |
Number |
% of subjects |
iodine |
|
|
<50 µg/ L |
2 |
0.7 |
50-100 µg/ L |
5 |
1.8 |
>100 µg/ L |
263 |
97.5 |
Total |
270 |
100 |
Iodine content of salt |
Number
|
% of subject |
0 ppm |
17 |
3.2 |
<15 ppm |
46 |
8.5 |
>15 ppm |
477 |
88.3 |
Total |
540 |
100 |
Discussion
According to WHO/UNICEF/ICCIDD, a total goitre rate
of 5% or more in primary school children (6-12 yr) is used to signal the
presence of a public health problem [3]. Overall prevalence of goitre in
the present study was 12.6%. There is a wide variation in prevalence of
goitre across the country. The prevalence ranged from 2.6 % to 67% as
observed in different studies [4-9]. This variation in goitre prevalence
could be due to geographical disparity in the country along with the
probable environmental and dietary iodine deficiencies. Additionally
this could be due to variation in the methodology adopted in terms of
sample size and age group included in the study.
Estimation of iodine content in salt samples showed
that 11.7 % of the powdered salt samples did not had adequate iodine
content (15 ppm and above). That means advice on powdered salt use does
not ensure adequate iodine intake. This problem can be addressed by
advocating the use of fresh stock of iodized salt available in the
market. Alternatively, iodine content of the salt should be monitored
regularly by health authorities by salt testing kits to ensure adequate
iodine content in the iodized salt.
In the present study it was observed that prevalence
of goitre increased with that of age. This could be due to higher demand
of iodine during adolescence. Prevalence of goitre was found to be
higher among females when compared to males. Similar observation was
made by Mohapatra, et al. [10]
One evident limitation of this study is that no
biochemical tests or hormonal estimation were conducted among children
with grade 2 goitre due to logistic constraints. Clinical populations
tend to differ from population-based samples in terms of several
factors. Secondly, diseases like autoimmune thyroiditis and presence of
goitrogens in the diet could account for some of the cases of goitre in
the present study. Further studies should also evaluate the above causes
of goitre among school children.
To conclude, findings of the present study
demonstrates that prevalence of goitre was high (12.6%) among children
in Ambala district and therefore it constitutes a public health problem
in this region. Strict implementation of salt iodization and marketing
in hard to reach areas is recommended as a measure to control the
situation.
References
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