The Relationship of Insulin-Like Growth Factor 2 to Fetal Growth and Adiposity

Abstract

Insulin-like growth factor 2 (IGF-2) is necessary for adequate human growth. Overexpression of the IGF2 gene is associated with fetal overgrowth and may play a role in the intrauterine programming of adipose tissue. As obesity in children is a major public health problem associated with early onset of comorbid metabolic diseases, identifying early life markers of obesity may serve as useful tool for counseling and implementation of preventive efforts before obesity develops. The relationship between IGF-2 and body composition is an emerging field of study and existing data are conflicting. In this review, we discuss the IGF2 gene and its function, highlight the proposed mechanisms for the effects of IGF-2 on adiposity, and examine the current literature studying the relationships between IGF-2 levels, changes within the IGF2 gene, weight, and adiposity. With additional study, IGF-2 may emerge as a useful marker of future obesity risk in infants.

Sex-Specific Associations of Maternal Gestational Glycemia with Hormones in Umbilical Cord Blood at Delivery

“…52 Cord blood IGF-2 has not been shown to correlate as strongly with fetal size at birth as IGF-1 in either normal pregnancies 53 or those complicated by diabetes 33 however, it has been shown to correlate with placental size. 33,53,54 DNA methylation of IGF-2 on the fetal side of placenta was associated with placental weight and newborn height, but not with birth weight. 55 While the etiology of the higher IGF-2 that we observed in male fetuses is unclear, male infants typically have a higher fetal:placental weight ratio, and this difference is postulated to contribute the higher rates of perinatal morbidity observed in males.…”

The insulin-like growth factor 2 gene and locus in nonmammalian vertebrates: Organizational simplicity with duplication but limited divergence in fish

“…The goals of the studies presented here were to understand the organization and patterns of expression of Igf2 genes in nonmammalian vertebrates by mining the resources of public databases and to place these findings in an evolutionary context with mammalian IGF2/Igf2 homologues and the mammalian IGF2/Igf2-H19 locus. In mammals, IGF2 is involved principally in mediating prenatal growth (8), but it also functions in other aspects of physiology and pathophysiology throughout life (9 -16). Mammalian IGF2/Igf2 genes are complicated and reside within a complex multigene locus (17,18,36,56).…”

“…The secreted peptide, insulin-like growth factor 2 (IGF2), is produced in many different mammals and nonmammalian vertebrates (1)(2)(3)(4)(5)(6) and is part of a small protein family with IGF1 and insulin (5,7). In mammals, IGF2 plays a central role in fetal development and growth (8) and is involved in a number of other physiological and pathological processes throughout life (9 -16). The single-copy gene encoding mammalian IGF2/Igf2 is embedded within a linkage group that includes tyrosine hydroxylase (TH/Th), INS (Ins2 in mice), H19, mitochondrial ribosomal protein L23 (MRPL23/Mrpl23), and troponin T3, fast skeletal type (TNNT3/Tnnt3) (17,18).…”

Sex‐specific associations of insulin‐like peptides in cord blood with size at birth

“…IGF‐1 is positively related to birthweight and birth length . Although less studied, IGF‐2 is also positively related to foetal growth parameters in some, but not in all studies . The foetal liver is a main production site of IGFs, however, several extrahepatic tissues also produce these growth factors.…”