Published in
Karger Publishers, Hormone Research in Paediatrics, 2(89), p. 122-131, 2018
DOI: 10.1159/000486035
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Correlation of Insulin-Like Growth Factor-I and -II Concentrations at Birth Measured by Mass Spectrometry and Growth from Birth to Two Months
,
Mairead Kiely,
Jonathan O’B Hourihane,
Alan D. Irvine,
Zengru Wu,
Yair Argon,
Richard E. Reitz,
Michael J. McPhaul,
Adda Grimberg
Full text: Unavailable
Abstract
<b><i>Background:</i></b> Immunoassays used to measure insulin-like growth factor (IGF)-I and -II concentrations are susceptible to interference from IGF-binding proteins. The aim of this study was to investigate the association of IGF-I and -II concentrations at birth with neonatal anthropometry using a liquid chromatography/mass spectrometry (LCMS) assay. <b><i>Methods:</i></b> LCMS was used to measure IGF-I and -II concentrations in umbilical cord blood of term, healthy infants enrolled in the Cork BASELINE Birth Cohort Study. Weight, length, and occipitofrontal head circumference (OFC) were measured at birth and 2 months. <b><i>Results:</i></b> Cord blood IGF-I and -II concentrations were measured in 1,100 infants. Mean (SD) IGF-I and -II concentrations were 52.5 (23.9) ng/mL and 424.3 (98.2) ng/mL, respectively. IGF-I and -II concentrations at birth were associated (<i>p</i> < 0.05) with weight (<i>R</i><sup>2</sup> = 0.19, R<sup>2</sup> = 0.01), length (<i>R</i><sup>2</sup> = 0.07, <i>R</i><sup>2</sup> = 0.004), and OFC (<i>R</i><sup>2</sup> = 0.03, <i>R</i><sup>2</sup> = 0.04) at birth. Low IGF-I concentrations at birth were associated with increases in weight (<i>p</i> < 0.001) and OFC (<i>p</i> < 0.01) <i>Z</i>-scores in the first 2 months. <b><i>Conclusion:</i></b> Using an LCMS assay, we have shown that anthropometric parameters at birth are associated with IGF-I and weakly with IGF-II concentrations. This indicates that, at the time of birth, IGF-I is the more important growth factor for regulating infant growth.