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We thank Ms. Pradhan for giving us an opportunity to provide more details
regarding our paper(1). The writer questions repre-sentativeness of
the children we studied, the size of the study group and critcises us
for not providing iodine content of salt and drinking water in Baroda.
In this context, we have the following response to offer:
1.
We deliberately studied children from 1 to 15 years of age rather
than 6 to 12 years of age because we wanted to establish the current
iodine status and the effect of goitrogens in all the sections of
a population by biochemical parameters, i.e., on the neonates,
preschool and school aged children. This selection is based on World
Health Organization (WHO) criteria of target groups that includes
neonates, infants and preschool children, school-aged children, pregnant
women and adults depending upon vulnerability, represen-tativeness,
accessibility, etc.(2). Generally 6-12 years is the preferred
recommended age by WHO for the study of thyroid size by palpation
alone. Thyroid size should be measured preferably by ultrasound when
goiter grades 0 and 1 predominate and this statement is based on our
earlier presented data of past and present indicators of iodine deficiency
disorders in 530 school-children(3). This was possible due to adoption
of a new thyroid volume refer-ence by WHO based on 3474 European schoolchildren
in 6-15 year age group(4). We have also studied iodine deficiency
disorders in adults(5).
2.
The sample size of 242 from Baroda is not small for scientifically
valid interpretation because we have reported goiter preva-lence in
a similar population in almost 100% of children by ultrasound(3).
Goiter indicates a past history of likely iodine deficiency and require
a minimum of 6-12 months of iodine deficiency and when the prevalence
of goiter is almost 100% one needs to do only very few samples to
confirm the current status of iodine deficiency by biochemical parameters.
For example, if goiter rate is 95% and a precision of 20%, one needs
just 5 samples and with a precision of 5% one needs 81 subjects.
3.
As regarding WHO recommendations on the interpretation of urinary
iodine excre-tion levels (UIE) of more than 300 µg/L, we would like
to draw attention to a recent WHO recommendation (mid 1999) on the
prevalence indicators. This is 5 years after its first recommendation
in 1994. More than 300 µg/L is considered as indicat- ing more than
an adequate intake of iodine.
4.
Regarding not providing the results of measurements of iodine content
in salt and drinking water, we have to say that the information is
given in the abstract as well as in the text just before the discussion.
5.
Regarding the statement that the median urinary iodine excretion levels
have not been mentioned in the manuscript we would like to draw the
attention on tables provided where median urinary iodine with interquartile
range and the means with SD have been given for each district by gender.
S.R.
Brahmbhatt,
R.M. Brahmbhatt,
C.J. Eastman,
S.C. Boyages,
Westmead Hospital and Institute of Clinical Pathology and Medical
Research,
Westmead, NSW 2145, Australia.
References
1.
Brahmbhatt SR, Fearnley RA, Brahmbhatt RM, Eastman CJ, Boyages SC.
Biochemical assess-ment of iodine deficiency disorders in Baroda and
Dang districts of Gujarat State: A study of 1363 children. Indian
Pediatr 2001; 38: 247-255.
2.
WHO/UNICEF/ICCIDD. Indicators for assess-ing IDD and their control
through salt iodina-tion. Geneva: World Health Organization, WHO/NUT/1994;
6L 1994.
3.
Brahmbhatt SR, Brahmbhatt RM, Boyages SC. Thyroid ultrasound is the
best prevalence indi-cator for the assessment of Iodine Deficiency
Disorders: A study in rural/tribal school children from Gujarat (Western
India): Eur J Endocrinol 2000; 143: 37-46.
4.
World Health Organization and International Council for the Control
of Iodine Deficiency Disorders, WHO/ICCIDD. Recommended normative
values for thyroid volume in children agd 6-15 years. Bull WHO 1997;
75: 95-97.
5.
Brahmbhatt SR, Fearnley RA, Brahmbhatt RM, Eastman CJ, Boyages SC.
A study of bio-chemical prevalence indicators for the assess-ment
of iodine deficiency disorders in adults at field conditions in Gujarat
(India). Asian Pacific J Clin Nutr 2001; 10: 51-57.
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