TY - JOUR

T1 - Adiposity in Children Born Small for Gestational Age Is Associated With β-Cell Function, Genetic Variants for Insulin Resistance, and Response to Growth Hormone Treatment

AU - Thankamony, Ajay

AU - Jensen, Rikke Beck

AU - O'Connell, Susan M

AU - Day, Felix

AU - Kirk, Jeremy

AU - Donaldson, Malcolm

AU - Ivarsson, Sten A

AU - Söder, Olle

AU - Roche, Edna

AU - Hoey, Hilary

AU - Ong, Ken K

AU - Dunger, David B

AU - Juul, Anders

PY - 2016

Y1 - 2016

N2 - BACKGROUND: Genetic susceptibility to insulin resistance is associated with lower adiposity in adults. Insulin resistance, and therefore adiposity, may alter sensitivity to GH. We aimed to determine the relationship between adiposity, genetic susceptibility to insulin resistance or insulin secretion, and response to GH treatment in short children born small for gestational age (SGA).METHODS: In 89 short prepubertal SGA children (age, 6.2 ± 1.6 y; 55 boys) treated with GH for 1 year in a multicenter study, body fat percentage was estimated at baseline and 1 year using dual-energy x-ray absorptiometry. The main outcome measures were treatment-related changes in height, IGF-1 standard deviation score, insulin sensitivity, insulin secretion, and disposition index. Combined multiallele gene scores based on single nucleotide polymorphisms with known associations with lower insulin sensitivity (gene scores for insulin resistance [GS-InRes]) and insulin secretion (gene scores for insulin secretion [GS-InSec]) were analyzed for their relationships with adiposity.RESULTS: Mean percentage body fat at baseline was low compared to normative data (P = .045) and decreased even further on GH treatment (baseline vs 1-year z-scores, -0.26 ± 1.2 vs -1.23 ± 1.54; P < .0001). Baseline percentage body fat was positively associated with IGF-1 responses (p-trends = .042), first-year height gains (B [95% confidence interval], 0.61 cm/y [0.28,0.95]; P < .0001), insulin secretion at baseline (p-trends = .020) and 1 year (p-trends = .004), and disposition index at 1 year (p-trends = .024). GS-InRes was inversely associated with body mass index (-0.13 SD score per allele [-0.26, -0.01]; P = .040), body fat (-0.49% per allele [-0.97, -0.007]; P = .047), and limb fat (-0.81% per allele [-1.62, 0.00]; P = .049) at baseline. During GH treatment, GS-InRes was related to a lesser decline in trunk fat (0.38% per allele [0.16, 0.59]; P = .001) and a higher trunk-limb fat ratio at 1 year (0.04 per allele [0.01, 0.08]; P = .008). GS-InSec was positively associated with truncal fat (0.36% per allele [0.09, 0.63]; P = .009).CONCLUSIONS: Adiposity in SGA children has favorable effects on GH sensitivity and glucose metabolism. The associations with multiallele scores support a causal role of insulin resistance in linking lesser body fat to reduced sensitivity to exogenous GH.

AB - BACKGROUND: Genetic susceptibility to insulin resistance is associated with lower adiposity in adults. Insulin resistance, and therefore adiposity, may alter sensitivity to GH. We aimed to determine the relationship between adiposity, genetic susceptibility to insulin resistance or insulin secretion, and response to GH treatment in short children born small for gestational age (SGA).METHODS: In 89 short prepubertal SGA children (age, 6.2 ± 1.6 y; 55 boys) treated with GH for 1 year in a multicenter study, body fat percentage was estimated at baseline and 1 year using dual-energy x-ray absorptiometry. The main outcome measures were treatment-related changes in height, IGF-1 standard deviation score, insulin sensitivity, insulin secretion, and disposition index. Combined multiallele gene scores based on single nucleotide polymorphisms with known associations with lower insulin sensitivity (gene scores for insulin resistance [GS-InRes]) and insulin secretion (gene scores for insulin secretion [GS-InSec]) were analyzed for their relationships with adiposity.RESULTS: Mean percentage body fat at baseline was low compared to normative data (P = .045) and decreased even further on GH treatment (baseline vs 1-year z-scores, -0.26 ± 1.2 vs -1.23 ± 1.54; P < .0001). Baseline percentage body fat was positively associated with IGF-1 responses (p-trends = .042), first-year height gains (B [95% confidence interval], 0.61 cm/y [0.28,0.95]; P < .0001), insulin secretion at baseline (p-trends = .020) and 1 year (p-trends = .004), and disposition index at 1 year (p-trends = .024). GS-InRes was inversely associated with body mass index (-0.13 SD score per allele [-0.26, -0.01]; P = .040), body fat (-0.49% per allele [-0.97, -0.007]; P = .047), and limb fat (-0.81% per allele [-1.62, 0.00]; P = .049) at baseline. During GH treatment, GS-InRes was related to a lesser decline in trunk fat (0.38% per allele [0.16, 0.59]; P = .001) and a higher trunk-limb fat ratio at 1 year (0.04 per allele [0.01, 0.08]; P = .008). GS-InSec was positively associated with truncal fat (0.36% per allele [0.09, 0.63]; P = .009).CONCLUSIONS: Adiposity in SGA children has favorable effects on GH sensitivity and glucose metabolism. The associations with multiallele scores support a causal role of insulin resistance in linking lesser body fat to reduced sensitivity to exogenous GH.

KW - Absorptiometry, Photon

KW - Adiposity

KW - Body Composition

KW - Body Height

KW - Child

KW - Child, Preschool

KW - Female

KW - Genetic Variation

KW - Genotype

KW - Glucose

KW - Human Growth Hormone

KW - Humans

KW - Infant, Newborn

KW - Infant, Small for Gestational Age

KW - Insulin

KW - Insulin Resistance

KW - Insulin-Like Growth Factor I

KW - Insulin-Secreting Cells

KW - Male

KW - Pancreatic Function Tests

KW - Recombinant Proteins

KW - Treatment Outcome

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1210/jc.2015-3019

DO - 10.1210/jc.2015-3019

M3 - Journal article

C2 - 26588449

VL - 101

SP - 131

EP - 142

JO - Journal of Clinical Endocrinology and Metabolism

JF - Journal of Clinical Endocrinology and Metabolism

SN - 0021-972X

IS - 1

ER -