Growth Hormone Therapy in Short Children Born Small for Gestational Age: Effects on Abdominal Fat Partitioning and Circulating Follistatin and High-Molecular-Weight Adiponectin

Abstract

A high sensitivity to insulin and a low amount of sc fat are among the hallmarks of short children born small for gestational age (SGA). We studied the effects of GH therapy on fat partitioning (including in the abdominal region) and circulating levels of triacylglycerol and newly identified adipokines, such as follistatin and high-molecular-weight (HMW) adiponectin in short SGA children. The study was conducted at a university hospital. Patients included 35 short SGA children (mean age 7 yr, height -3.1 sd). All children received GH but they were randomized for an early start (GH for 4 months) vs. a delayed start (untreated for 4 months, then GH for 4 months). Mean GH dose after 4 months was 36 microg/kg x d. Outcomes included fasting serum glucose, insulin, triacylglycerol, HMW adiponectin, follistatin; body size and composition; and abdominal fat partitioning. GH therapy was accompanied by robust changes toward the norm (height, weight, lean mass, follistatin) but also by changes away from the norm (low HMW adiponectin, high triacylglycerol). Some baseline anomalies were amplified (more deficit of sc fat, both at total body level and in the abdominal region), whereas other baseline anomalies were overcorrected (from a highly insulin sensitive state to an insulin resistant state). GH therapy in short SGA children is accompanied by not only a more normal body size and follistatinemia but also insulin resistance, hypo-HMW-adiponectinemia, hypertriacylglycerolemia, and an amplification of the deficit in sc fat.