Open AccessExchangeable Zinc Pool Size at Birth in Pakistani Small for Gestational Age and Appropriate for Gestational Age Infants Do Not Differ But Are Lower Than in US Infants
Author(s) -
Ariff Shabina,
Krebs Nancy F.,
Westcott Jamie E.,
Hambidge Michael,
Miller Leland V.,
Rizvi Arjumand,
Soofi Sajid B.,
Bhutta Zulfiqar A.
Publication year - 2018
Publication title -
journal of pediatric gastroenterology and nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.206
H-Index - 131
eISSN - 1536-4801
pISSN - 0277-2116
DOI - 10.1097/mpg.0000000000001778
Subject(s) - small for gestational age , medicine , gestational age , birth weight , pediatrics , appropriate for gestational age , zinc deficiency (plant disorder) , obstetrics , zinc , pregnancy , micronutrient , genetics , pathology , biology , materials science , metallurgy
Objectives: Small for gestational age (SGA) infants are more susceptible to infectious morbidity and growth faltering compared to their appropriate for gestational age (AGA) counterparts. Zinc supplementation of SGA infants may be beneficial but the underlying susceptibility to zinc deficiency of SGA infants has not been examined. Methods: In a community‐based, observational, longitudinal study in a peri‐urban settlement of Karachi, Pakistan, we compared the size of the exchangeable zinc pools (EZPs) in term SGA and AGA infants at birth and at 6 months of age, hypothesizing that the EZP would be lower in the SGA group. To measure EZP size, a zinc stable isotope was intravenously administered within 48 hours of birth (n = 17 and 22) at 6 months (n = 11 and 14) in SGA and AGA infants, respectively. Isotopic enrichment in urine was used to determine EZP. Results: No significant difference was detected in the mean (±standard deviation) EZP between SGA and AGA infants at birth, with values of 9.8 ± 3.5 and 10.1 ± 4.1 mg/kg, respectively ( P = 0.86), or at 6 months. Longitudinal EZP measurements demonstrated a significant decline in EZP relative to body weight in both groups at 6 months ( P < 0.001). Mean EZP (adjusted for body weight) size at birth for the combined Pakistani groups was significantly lower than AGA infants at birth in the United States ( P = 0.017). Conclusions: These results did not support a difference in zinc endowment between SGA and AGA Pakistani infants. They, however, do suggest lower in utero zinc transfer to the fetus in a setting where poor maternal nutritional status may confer a high susceptibility to postnatal zinc deficiency.