Nutritional Status, Growth Dynamics, and the Insulin-Like Growth Factor-1 Axis in Children across the Nutritional Spectrum

Abstract

Linear growth in childhood is governed by a dense network of genetic, endocrine, and environmental signals, among which nutritional status occupies a central regulatory position. Body mass index, its standardised expression as a standard deviation score, height standard deviation score, and height growth velocity together form the clinical vocabulary through which paediatricians track this process, while the growth hormone–insulin-like growth factor-1 axis provides the principal hormonal mechanism translating nutrient availability into skeletal growth. This narrative review synthesises contemporary evidence describing how these anthropometric and biochemical parameters interact across the full nutritional spectrum, from severe undernutrition and stunting through normal growth to overweight and obesity. Undernutrition is associated with hepatic growth hormone resistance, reduced insulin-like growth factor-1 synthesis, and diminished height velocity, a state that is at least partially reversible with nutritional rehabilitation and that underlies catch-up growth phenomena observed in malabsorptive disease and after severe acute malnutrition. Obesity, in contrast, is characterised by a biphasic pattern: prepubertal linear growth acceleration accompanied by relatively preserved or elevated insulin-like growth factor-1, followed by blunted pubertal growth velocity, early pubertal onset in girls, and a convergence of final height toward the population mean. The relationship between body mass index standard deviation score and insulin-like growth factor-1 standard deviation score is non-linear, following an inverted U-shape with a threshold beyond which further adiposity is associated with declining hormone concentrations. These findings carry direct implications for the clinical interpretation of insulin-like growth factor-1 in short-statured children of divergent nutritional status, for growth hormone dosing decisions, and for anthropometric surveillance strategies addressing the global double burden of malnutrition. The review concludes by identifying priority areas for future longitudinal and mechanistic research.