The Effect of Blood Zinc Level on the Growth of Children

Lee, Su Myung; Lee, Sun Woo; Rhie, Young Jun; Kim, Ji Young; Kim, Duk Hee; Kim, Ho Seong

Abstract

PURPOSE: Zinc is an essential nutrient, which is required to maintain the normal structure and/or function of multiple enzymes. Therefore, zinc nutriture has been known to influence the physical growth of young children. This study was desinged to evaluate the relationship between blood zinc levels and growth parameters in children.
METHODS
Two hundred eighty three children (150 boys and 133 girls) who visited the Youngdong Severance Hospital as short stature were enrolled in this study. Height standard deviation score (Ht. SDS), weight standard deviation score (Wt. SDS), and pubertal stage were obtained for each children. Blood samples were collected for zinc, alkaline phosphatase (ALP), insulin-like growth factor binding protein-3 (IGFBP-3), insulin-like growth factor-1 (IGF-1), and free thyroxine (fT4). The relationship between blood zinc levels and growth status, and growth factors were analyzed.
RESULTS
The Ht. SDS and Wt. SDS were -0.16+/-0.99, 0.16+/-0.88 respectively for the low blood zinc level group; the Ht. SDS and Wt. SDS were -0.16+/-0.97, 0.08+/-0.93 respectively for the normal blood zinc level group. Between two groups, Ht. SDS, Wt. SDS, bone age, pubertal stage, ALP, and IGF-1 showed no significant differences, while IGFBP-3 and fT4 showed significant differences (P<0.05). The mean zinc concentrations showed no significant difference between the normal stature group and short stature group (101.60+/-41.11 microgram/dL, 93.72+/-35.38 microgram/dL respectively). The Ht. SDS, Wt. SDS, pubertal stage, ALP, and IGF-1 showed no significant correlation with the zinc levels, while the IGFBP-3 and fT4 showed significant correlation (P<0.05).
CONCLUSION
We could not find any significant relationship between blood zinc level and growth status. However, interpretation of our results should be cautious in aspect that the result might come from the subjects with mild zinc deficiency. Further study is required to investigate the severe zinc deficiency patients and zinc replacement study.