Serum Adiponectin Levels, Insulin Resistance, and Lipids in Catch-Up and No Catch-Up Growth

Abstract

Catch-up growth is observed in 90% of infants born small for gestational age (SGA), while those large for gestational age (LGA) often exhibit catch-down growth. Preterm infants may experience catch-up growth after an early period of postnatal growth restriction. Catch-up growth may have later adverse effects on insulin resistance (IR) and the lipids profile. It affects the body fat content and/or distribution, with possible changes in concentration of hormones secreted by adipose tissue, including those that modulate insulin sensitivity, such as adiponectin (Ad). IR is increased in full-term SGA individuals with catch-up growth and unaffected or decreased in those without catch-up growth. The increase in IR is observed as early as the third year of life and persists into adult life. Ad levels are consistently lower in full-term SGA prepubertal children who experience catch-up growth, while those with no catch-up growth have Ad levels similar to or lower than normal subjects. An inverse relationship between Ad and IR indices has been demonstrated in SGA children, but in adulthood the relationship curve may become U-shaped. Ad is related positively with birth weight (BW) and negatively with visceral adiposity. Ad remains low in SGA individuals until adulthood, suggesting that these disturbances are permanent. Prepubertal LGA children with normal body mass index (BMI) are insulin resistant, even those of healthy non-diabetic pregnancies, but there is inconsistency in their Ad levels. Preterm birth is associated with IR, and both fetal growth and childhood weight gain can affect IR indices during childhood. Limited evidence suggests that the combination of SGA and prematurity does not appear to result in IR greater than that in full-term SGA children. In full-term SGA individuals lack of catch-up growth in height is associated with an increase in t-CH or LDL-CH. Conversely, lipid metabolism is unaffected in SGA subjects with catch-up growth in BMI during childhood, provided they do not become overweight, but when full-term SGA individuals become obese during childhood they may have higher triglyceride levels than obese appropriate for gestational age (AGA) children. LGA children born to non-diabetic mothers may have normal lipid levels or higher protective HDL-C, but an abnormal lipid profile is observed in those born to mothers with poorly controlled diabetes during gestation. Postprandial triacylglycerol levels have been found increased in preterm-SGA men, although other studies in preterm subjects found no disturbances in lipids.