Plasma β-endorphin and insulin concentrations in relation to body fat and nutritional parameters in overweight and obese prepubertal children

To investigate the relationship between plasma beta-endorphin (beta-end) and insulin concentrations and 1) body fat, and 2) nutritional parameters in overweight or obese prepubertal children. Cross-sectional study on plasma beta-end and insulin concentrations, body fat, indirect parameters of appetite namely daily energy and macronutrient intake. 143 (67 boys and 76 girls) overweight or obese children (group I) and 48 (27 boys and 21 girls) healthy children with normal parameters of somatic development (group II). Age: 5.8-9.6 y. Weight, height and subcutaneous skinfold thicknesses, plasma beta-end and insulin concentrations, diet history for energy and macronutrient intake. Group I was characterised by significantly higher average concentrations of beta-end and insulin in comparison to the control group. The analysis of these concentrations in the subgroups in relation to the percentage of body fat indicates that beta-end concentrations increased more than insulin concentrations with increasing fatness. A significantly positive correlation between beta-end and insulin levels was only noted in group I. Also, only in this group was there a significant positive correlation between beta-end levels and energy and macronutrient intake. In both groups the percentage of energy intake which was fat, correlated positively with beta-end concentrations. Furthermore energy and fat intakes showed a significant positive correlation with insulin levels in both groups. beta-endorphin and insulin concentrations in overweight and obese prepubertal children are not only higher than in non-obese children but also are positively correlated with each other and with the percentage of body fat. The relationship between plasma beta-end levels and food intake shows that the beta-end level may be able to be used as an indicator of appetite in overweight and obese prepubertal children whose food intake is not restricted.