Effect of Oral Glucose Administration on Ghrelin Levels in Normal-Height Prepubertal Children Born Small for Gestational Age (SGA)

TL;DR

This study found that ghrelin levels in children born small for gestational age are affected by obesity and insulin sensitivity, not just body fat.

Contribution

The study reveals that ghrelin regulation in SGA children is more closely tied to insulin sensitivity than to adiposity.

Findings

Ghrelin levels decreased significantly during the oral glucose tolerance test.

Obese SGA children had lower ghrelin levels and a smaller decline compared to non-obese peers.

Fasting ghrelin and its suppression were independently associated with insulin resistance.

Abstract

Ghrelin is a regulator of appetite and growth hormone secretion, rising during fasting and decreasing after food intake. Children born small for gestational age (SGA) who undergo postnatal catch-up growth are at increased risk of obesity and metabolic disturbances, which may be related to impaired ghrelin regulation. This study assessed fasting and post-glucose ghrelin responses during an oral glucose tolerance test (OGTT) in prepubertal SGA children in relation to obesity and metabolic syndrome components. Ninety-eight children aged 5–9 years were included. Anthropometry, blood pressure, fasting lipids, glucose, insulin, and ghrelin were measured; BMI SDS and HOMA-IR were calculated. Ghrelin concentrations were assessed at baseline and 120 min after glucose ingestion. Ghrelin levels declined significantly during OGTT. Obese SGA children showed lower fasting and post-load ghrelin levels and a smaller decline compared with non-obese peers. Fasting and post-load ghrelin correlated inversely with BMI SDS, waist circumference, and insulin levels. In regression analyses, fasting ghrelin and its suppression were independently associated with HOMA-IR, whereas post-load ghrelin was determined by post-load insulin. These findings indicate that ghrelin dynamics in SGA children are more closely related to insulin sensitivity than adiposity and are blunted in the presence of obesity.

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