Iron deficiency in goitrous schoolchildren of Semirom, Iran

A community-based case-control study to investigate the role of iron deficiency in the persistence of goiter

OBJECTIVES

To find out the magnitude of iron deficiency anemia in the age group of 6-12 years and investigate the role of iron deficiency as a possible contributor to endemic goiter in school children in Ambala.

MATERIALS AND METHODS

The present study was conducted as a subset of a cross-sectional study among 2700 children from 6 to 12 years of age to find out the prevalence of goiter. All the subjects who were found to be suffering from goiter in the cross-sectional study were enrolled in the case-control study as cases and were compared with age- and sex-matched controls (children without goiter) from the same cohort. The study was conducted from February 2011 to January 2012.

RESULTS

Out of total, goiter was observed in 12.6% of the subjects. Urinary iodine excretion was found to be <100 μg/L in 57 (10.5%) children. Mean hemoglobin (Hb) level of the study population was 11.9 g/dL. It was noted that 71% of the goitrous children had anemia (Hb <12 g/dL) as compared to 63.7% of the control group. Serum ferritin (SF) was <15 ng/mL in 70% of the children. The mean ± standard deviation of SF in the goitrous and nongoitrous children was 19.65 ± 32.51 μg/L and 27.55 ± 21.07 μg/L, respectively (P = 0.012).

CONCLUSION

The findings in the study suggest that iron deficiency anemia in children is contributing toward the persistence of goiter in the postiodization phase.

The Association between Cobalt Deficiency and Endemic Goiter in School-Aged Children

BACKGROUND

In Iran, an iodine deficiency control program was initiated in 1989 by iodizing salt. Despite this program, goiters have remained an endemic condition in most parts of Iran. Thus, it is possible that other factors aside from iodine deficiency may contribute to endemic goiter. The aim of this study was to investigate the association between cobalt deficiency and endemic goiter in a region of Iran with a high prevalence of goiter.

METHODS

A cross-sectional study was conducted among school children aged 9 to 11 years in the city of Kerman, Iran. In the first phase of the study, a multistage, proportional-to-size, cluster sampling method was used to screen 5,380 out of 29,787 students. After the screening phase, 170 students (130 goitrous and 40 nongoitrous) were randomly selected, and serum and urine specimens were obtained. We measured thyroid function, serum cobalt level, and urinary iodine excretion. Univariate and multiple logistic regression analyses were performed.

RESULTS

The prevalence of grade 2 goiters was 34.8% (95% confidence interval [CI], 31.5 to 42.5), with both sexes being equally affected. The weight and body mass index of goitrous subjects was significantly lower (P<0.001) than those of nongoitrous subjects. The serum cobalt levels were lower in goitrous subjects than in nongoitrous subjects (4.4±2.9 µg/L vs. 6.4±2.7 µg/L). The urinary iodine levels were also lower in goitrous subjects than in nongoitrous subjects (198.3±108.3 µg/L vs. 270.2±91.1 µg/L). Multiple regression analysis showed that only cobalt deficiency, not iodine deficiency, significantly contributed to the presence of goiter (odds ratio, 0.78; 95% CI, 0.61 to 0.99; P=0.042).

CONCLUSION

Cobalt deficiency may be an important independent predicator for goiter in endemic regions, especially areas in which goiters persist despite salt iodization programs.

Ultrasonographic evaluation of the thyroid gland volume among 8-15-year-old children in Isfahan, Iran

Background:

Local reference data are needed in the screening of children for thyroid enlargement. We determined the thyroid gland volume using the ultrasonography (US) in schoolchildren of Isfahan, Iran.

Materials and Methods:

A total of 360 schoolchildren (59% girls) aged 8-15 years who met the study criteria were entered the study. Clinical grading of goiter was performed by an endocrinologist according to the World Health Organization (WHO) classification. Then, a single expert radiologist performed thyroid volume measurement using a portable ultrasound device. Urinary iodine (UI) concentration was checked in 36 randomly selected cases.

Results:

On physical examination, 327 (91%), 32 (8.8%) and 1 (0.2%) subjects were classified as normal, borderline and goiter Grade 2. Mean thyroid volume measured by US was 1.46 ± 0.70 ml. Thyroid volume in boys was significantly higher than girls (1.58 ± 0.67 ml vs. 1.38 ± 0.71 ml; P = 0.009). Thyroid volume was positively correlated with the clinical grade of the goiter (r = 0.30, P < 0.001) and with age (r = 0.25, P < 0.001). Both median and 95^th percentile of thyroid volume of our subjects was lower than the reference values reported by WHO. Median of UI was 16.90 μg/dl. UI was not correlated with thyroid volume (r = 0.12, P = 0.46).

Conclusion:

The thyroid size in Isfahanian schoolchildren is lower than the reference values reported by WHO. These data could be used in determining local reference in the screening of children for thyroid enlargement.

Residual goiter in Semirom; iodine status and thiocyanate overload do not play a role

This study was performed to investigate the role of thiocyanate overload in the etiology of endemic goiter in schoolchildren of Semirom, Iran. A total of 1828 schoolchildren were selected by multi-stage random sampling. Urinary iodine concentration (UIC) and urinary thiocyanate (USCN) were measured in a group of these children. The median UIC was 18.5 microg/dl. The mean +/- SD of USCN in goitrous and nongoitrous subjects did not differ significantly (0.75 +/- 0.78 mg/dl vs. 0.63 +/- 0.40 mg/dl; p = 0.30). Finally, we concluded that neither iodine deficiency nor thiocyanate overload contributed to the high prevalence of goiter in Semirom. The role of other goitrogenic factors should be investigated in this region.

Endemic goiter in Semirom; there is no difference in vitamin A status between goitrous and nongoitrous children

BACKGROUND

Despite long-standing iodine supplementation in Iran, the prevalence of goiter remains high in some areas. This suggests other nutritional deficiencies may be considered as responsible factors for goiter persistence. In the present study we investigated the possible role of vitamin A deficiency (VAD) and low vitamin A status in the etiology of endemic goiter in Semirom, Iran.

MATERIALS AND METHODS

In this cross-sectional study, 1,828 students from 108 primary schools of urban and rural areas of Semirom were selected by multistage random cluster sampling. Thyroid size was estimated in each child by inspection and palpation. Urinary iodine concentration (UIC) and serum retinol (SR) were measured.

RESULTS

Overall, 36.7% of schoolchildren had goiter. The median UIC was 18.5 microg/dL. The mean+/-SD of SR in goitrous and nongoitrous children was 38.84+/- 10.98 and 39.17+/-10.85 microg/dL respectively (p=0.82). There were two children with VAD (SR less than 20 microg/dL); one in the goitrous and one in the nongoitrous group. The prevalence of subjects with low vitamin A status (SR less than 30 microg/dL) in the goitrous and nongoitrous groups was 26.2 and 21.5% respectively (p=0.42).

CONCLUSION

Goiter is still a public health problem in this region. Iodine deficiency, VAD or low vitamin A status is not among the contributors of goiter persistence in schoolchildren of Semirom. The role of other micronutrient deficiencies or goitrogens should be investigated.