Low plasma levels of insulin-like factor-1 among children affected by trichuris dysentery syndrome

ABSTRACT

Children with the Trichuris Dysentery Syndrome (TDS) are both stunted and wasted. Following treatment, these children show rapid gain in height and weight. Levels of insulin-like growth factor-1 (IGF-1), the main mediator of growth hormone (GH) in plasma, have been related to growth velocity. We therefore looked at the relationship between IGF-1 and the anthropometric and biochemical indices of growth in a group of 14 children (2-10 years old) affected by TDS (cases). We also looked at the same indices in 28 unaffected (control) children matched by age, gender, neighbourhood and socio-economic status. The cases were admitted to the Tropical Metabolism Research Unit (TMRU) and treated with albendazole and iron. The following series of anthropometric measurements height (Ht), weight (Wt), head circumference (HC), mid-upper arm circumference (MCA), triceps and subscapular skinfold thicknesses were made at predetermined intervals for one year. On each measuring day, blood samples were drawn for plasma IGF-1 determination by radioimmunoassay (RIA). On admission, the mean levels of plasma IGF-1 were significantly lower in the cases than in the controls. More than half of the individual cases (57 percent) fell below the IGF-1 assay reference levels for their age and gender, the others were at the low end of the range. All of the control levels were within the reference range. Three weeks after hospital discharge (approximately 4 weeks after worm expulsion) the cases had a significant rise in levels of plasma IGF-1 mean = 13.09, SD = 2.97, SEM = 0.86, but were still significantly lower than the controls, 95 percent CI (-11.34, -2.19), p = 0.008. Three months after treatment, there was no significant difference in mean plasma IGF-1 levels between the cases and the controls. This study indicates that low circulating IGF-1 is associated with reduced collagen synthesis. Levels of plasma IGF-1 are correlated with the anthropometric indices of growth and nutrition and reflect the severity of disease in these children (AU)