OBJECTIVETo analyze the association between thyroid volume and physical growth of school-age children, and to compare volume indexes of individual thyroids for reference of selection of assessment indicators.

METHODSAll the students of the 12 classes of grades 3-5 at a primary school in Minhang district, Shanghai were rounded up with a multi-stage cluster sampling, for physical examinations to measure their height, weight, Body mass index (BMI) and body surface area (BSA), followed by B-ultrasonography to measure their thyroid volume. Data of the measurements were calculated to learn their height corrected volume index (HVI), weight and height corrected volume index (WHVI), BMI corrected volume (BMIV), and BSA corrected volume (BSAV) individually. Their urine and salt samples were collected to measure iodine concentration in urine and salt. Individual indexes were studied for their association with the growth and development indexes of children.

RESULTSThyroid volume data were collected for 485 students, including 258 boys (53.2%) and 227 girls (46.8%). Their height, weight, BMI and BSA were found to be positively correlated with their age (P < 0.05). For children of the same age group, their thyroid volume was also positively correlated with their physical development indexes. Of all the thyroid indexes, the difference between BSAV physical development factors had no statistical association (with partial-correlation coefficients for age, gender, height, and weight being 0.07, 0.05, 0.01 and 0.02 respectively), and their thyroid volume, HVI, BMI and weight were correlated to age, height and weight.

CONCLUSIONThyroid volume was associated with age and weight. It was inappropriate to diagnose goiter with criteria of age, gender and thyroid volume. BSAV was recommended for its non-association with age, gender and weight and its stability.