Thyroid volume measurement by ultrasound in children as a tool for the assessment of mild iodine deficiency.

Abstract

Thyroid ultrasound was used to measure thyroid volume in children and compared with thyroid palpation for the assessment of the prevalence of goiter in an area of mild iodine deficiency. School children, 6-14 yr old, were from control areas (n = 2693; urinary iodine excretion, 110 micrograms/L) or from an area of mild iodine deficiency (IDA; n = 278; urinary iodine excretion, 72 micrograms/L). Thyroid volume determined by ultrasound in control children increased with age (r = 0.62; P < 0.0001) and was significantly correlated with height (r = 0.51; P < 0.0001) and body weight (r = 0.126; P < 0.0001). Both median and mean thyroid volumes were greater in IDA children than in controls. The prevalence of goiter determined by ultrasound was 68 of 268 children (25.3%) in IDA and 105 of 2693 children (3.9%) in the control area (chi 2 = 204; P < 0.0001). Thyroid enlargement, as assessed by palpation, was found in 59 of 268 children (22%) in the IDA group and in 165 of 2693 (6.1%) subjects in the control area (chi 2 = 88; P < 0.0001). Some subjects of the IDA who were judged goitrous by palpation (11.2%) had a normal thyroid volume at ultrasound, and 12.7% of subjects with an abnormal thyroid volume at ultrasound were judged nongoitrous by palpation. In conclusion, 1) thyroid volume in children, as assessed by ultrasound, increases with age and is closely related to the parameters of body growth; 2) in every age group, thyroid ultrasound shows greater thyroid volume in an IDA group than in controls; and 3) a discrepancy between palpation and ultrasound is found in 23.9% of children living in an IDA, confirming that palpation is relatively inaccurate for assessing the prevalence of goiter in mild iodine deficiency. These data indicate that thyroid volume measurement by ultrasound in children provides a useful tool for the assessment of goiter in mild iodine deficiency.

Mild iodine deficiency in a sample of New Zealand schoolchildren

“…There were no significant differences between the median thyroid volumes of boys and girls in this study. Only Delange et al (1997) and Foo et al (1999) report significant differences in thyroid volumes between boys and girls, while most other studies have found no differences (Hess & Zimmermann, 2000;Langer et al, 1994;Liesenkötter et al, 1997;Vitti et al, 1994;Xu et al, 1999). Foo et al (1999) state, however, that in their study the differences in thyroid volumes between boys and girls were small and suggest a unisex reference for children aged up to 10 y old.…”

“…There has been discussion in the literature regarding the appropriateness of the 1997 reference data; the WHO=ICCIDD=UNICEF median and ULN values are similar to those found in a few studies of iodine-replete children (Büurgi et al, 1999;Vitti et al, 1994), but higher than those found in a number of other studies (Foo et al, 1999;Gutekunst & Martin-Teichert, 1993;Hess & Zimmermann, 2000;Liesenkötter et al, 1997;Xu et al, 1999). Recently a set of provisional reference values has been published that are approximately 30% smaller than the 1997 values, in an effort to correct for the large systematic measurement bias shown to be apparent in the 1997 reference data (Zimmerman et al, 2001).…”

Effect of oral iodized oil on thyroid size and thyroid hormone metabolism in children with concurrent selenium and iodine deficiency

“…In a study of goitrous adults in Zaire, 118 mg oral iodine reduced thyroid size as measured by a thyroid tracing method by 36% at 3 months and 52% at 1 y (Tonglet et al, 1992). In the present study, we used thyroid ultrasonography, a more precise and objective method of measuring goiter size (Vitti et al, 1994).…”

Ultrasonographic determination of goiter prevalence in southern Brazilian schoolchildren

“…Epidemiological studies measuring thyroid volume by ultrasonography and taking into account height, body weight and age have reported a goiter prevalence of 3.9% in iodine-sufficient areas (13). In iodine-deficient areas in Italy (13) and around Chernobyl in the former Soviet Union (14), the reported prevalence of goiter was 25.3 and 35.9%, respectively.…”