Background and methods We investigated the frequency of zinc deficiency in Japanese children with idiopathic short stature, and evaluated whether serum zinc levels correlated with background factors, including age and standard deviation scores (SDSs) for height and serum insulin-like growth factor (IGF)-1 levels. The study subjects consisted of 89 Japanese children. Results The mean serum zinc level was 79 ± 12 (49-108) μg/dL. Of all the children, 48.3% had a low zinc level, in the 60-80 μg/dL range, and 6.7% had zinc deficiency with a zinc level below 60 μg/dL. The majority with a low zinc level and zinc deficiency were asymptomatic other than for short stature. We found no significant correlations of serum zinc with age, or the SDSs for height and serum IGF-1 levels, in either the entire subject population or those with a zinc level below 80 μg/dL. Conclusions We found a low zinc level to be common in Japanese children with idiopathic short stature, whereas actual zinc deficiency was rare. However, other as yet unknown mechanisms not associated with the growth hormone (GH)-IGF-1 axis could be involved in growth retardation in idiopathic short stature.
Keywords: Japanese; children; idiopathic short stature; insulin-like growth factor-1 (IGF-1); serum zinc level; zinc deficiency.