%0 Journal Article
%T Maternal BMI, IGF-I Levels, and Birth Weight in African American and White Infants
%A Adriana C. Vidal
%A Amy P. Murtha
%A Susan K. Murphy
%A Kimberly Fortner
%A Francine Overcash
%A Nikki Henry
%A Joellen M. Schildkraut
%A Michele R. Forman
%A Wendy Demark-Wahnefried
%A Joanne Kurtzberg
%A Randy Jirtle
%A Cathrine Hoyo
%J International Journal of Pediatrics
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/191472
%X At birth, elevated IGF-I levels have been linked to birth weight extremes; high birth weight and low birth weight are risk factors for adult-onset chronic diseases including obesity, cardiovascular disease, and type 2 diabetes. We examined associations between plasma IGF-I levels and birth weight among infants born to African American and White obese and nonobese women. Prepregnancy weight and height were assessed among 251 pregnant women and anthropometric measurements of full term infants (¡Ý37 weeks of gestation) were taken at birth. Circulating IGF-I was measured by ELISA in umbilical cord blood plasma. Linear regression models were utilized to examine associations between birth weight and high IGF-I, using the bottom two tertiles as referents. Compared with infants with lower IGF-I levels (¡Ü3rd tertile), those with higher IGF-I levels (>3rd tertile) were 130£¿g heavier at birth, ( , , ), after adjusting for gender, race/ethnicity, gestational age, delivery route, maternal BMI and smoking. Stratified analyses suggested that these associations are more pronounced in infants born to African American women and women with BMI ¡Ý30£¿kg/m2; the cross product term for IGF-I and maternal BMI was statistically significant ( ). Our findings suggest that the association between IGF-I levels and birth weight depends more on maternal obesity than African American race/ethnicity. 1. Introduction Low birth weight (LBW) and high birth weight (HBW) are both important indicators of suboptimal intrauterine development and have been linked to risk of several chronic diseases later in life. HBW has been associated with childhood and adult obesity [1] and some cancers, including breast [2] and prostate cancer [3], whereas LBW is a consistently identified risk factor for cardiovascular disease (CVD) [4, 5] and type 2 diabetes (T2D) [6, 7]. IGF-I is a mitogenic and antiapoptotic paracrine growth factor expressed in all fetal organs [8, 9], and is essential in fetal and neonatal growth, differentiation and development [10¨C14]. Several lines of evidence suggest that IGF-I levels are associated with birth weight [15¨C26]; furthermore higher IGF-I levels are associated with higher BW, but not with lower birth weight [16, 17, 26]. In adulthood, elevated concentrations of IGF-I are associated with an increased risk of obesity and many cancers, including breast, lung, head and neck, colorectal, pancreas, synovial sarcoma, and prostate cancer [26¨C31]. Although concentrations of circulating IGF-I levels vary considerably by race/ethnicity and maternal prepregnancy obesity, few studies
%U http://www.hindawi.com/journals/ijpedi/2013/191472/