Association between insulin-like growth factor-1, insulin-like growth factor-binding protein-1 and leptin levels with nutritional status in 1–3-year-old children, residing in the central region of Limpopo Province, South Africa

The present study evaluated levels of growth factors and their associations with nutritional status with emphasis on stunting in children at 1 and 3 years of age. A follow-up study on a birth cohort (n 219) of children from villages in the central region of the Limpopo Province was undertaken. Of the original cohort, 156 and 162 could be traced and assessed at ages 1 and 3 years, respectively. Data collected included socio-demographic characteristics, anthropometric measurements, dietary intake and fasting blood (collected from 116 and 145 children at 1 and 3 years, respectively) for growth factor analysis (insulin-like growth factor (IGF)-1, IGF binding protein (BP)-1, IGFBP-3, leptin, glucose and insulin). At 1 year it was found that stunted children had lower leptin levels while their IGFBP-1 levels were higher than that in normal children. These differences were, however, not observed at 3 years. Furthermore at 1 year the biochemical parameters were more related to length measures whereas at 3 years the parameters were more associated with weight measures. The observed stunting in this group of children may be a result of chronic undernutrition resulting in long-term growth faltering which is already evident at 1 year. Thus the observed phenomenon might be an adaptive mechanism adopted by children's metabolic processes as they grow up in an environment with inadequate essential nutrients due to poor weaning practices and consumption of a diet of poor quality, resulting in them gaining more weight at the expense of linear growth.