RESUMO
Background: Metabolic syndrome (MetS) in children is a rising health issue that is strongly associated with cardiovascular diseases and type 2 diabetes mellitus development. Low-affinity antibodies reactive to leptin and ghrelin are suggested to regulate hormone stability and function; nevertheless, the role of the leptin/ghrelin axis and antibodies reactive to both hormones in relation to MetS or its components in the pediatric population remains unknown. Methods: Fifty-eight children (7-12 years) were included and categorized according to the presence of one or more criteria for the diagnosis of MetS or according to body mass index. Body composition, biochemical variables, and metabolic risk indexes were determined. Antibodies reactive to leptin and ghrelin were quantified by an in-house enzyme-linked immunosorbent assay test. Ratios of leptin/ghrelin hormones and anti-leptin/anti-ghrelin immune complexes were obtained. Results: The biochemical variables glucose (P = 0.0009), insulin (P = 0.0001), leptin (P = 0.0036), HOMA-IR (homeostatic model assessment for insulin resistance) (P < 0.0001), and plasma atherogenic index (P < 0.0001) were significantly higher in children with two or three components of MetS (MetS 2-3) in comparison to children with none or one component (MetS 0-1). Ratios of leptin/ghrelin (P = 0.0307) and anti-leptin/anti-ghrelin immune complexes (P = 0.0338) were higher in MetS 2-3 group versus MetS 0-1 group. In MetS 2-3 group, both insulin (r = 0.4361, P = 0.0293) and HOMA-IR (r = 0.4761, P = 0.0161) were positively correlated with the leptin/ghrelin hormone ratio. Conclusions: The higher leptin/ghrelin hormone ratio scores observed in MetS 2-3 group, along with their correlation with insulin levels and HOMA-IR, highlight the role of leptin and ghrelin on insulin sensitivity and metabolic regulation. An increased ratio of anti-leptin/anti-ghrelin immune complexes suggests affinity changes in these antibodies that may lead to alterations in hormone function.
RESUMO
La evidencia científica sobre la caracterización de la conducta alimentaria señala que situaciones de privación de alimento, como el ayuno, aumentan el valor del alimento y modifican el patrón alimentario. En consecuencia se incrementa el consumo de alimentos y por ende el consumo calórico. La situación se agrava cuando los alimentos preferidos después del periodo de privación son poco saludables o se consumen en exceso convirtiéndose en detonadores de problemas de salud (Capaldi, 1993; Gottschalk, Libby & Graff, 2000; Vélez & Garcia, 2003). Con el objetivo de evaluar el efecto del ayuno sobre el consumo calórico y la modificación de las preferencias alimentarias, se diseñó un estudio en el cual participaron nueve jóvenes universitarios que fueron clasificados de acuerdo a su Índice de Masa Corporal (IMC) en tres grupos: Bajo-peso, Normo-peso y Sobre-peso. Fueron expuestos durante la línea base a ocho alimentos diferentes. Durante la fase experimental se expuso a los mismos participantes a un periodo de ayuno y posteriormente a los mismos alimentos registrando su consumo. Los resultados mostraron que el consumo calórico y la preferencia entre alimentos se modificaron. El grupo Bajo-peso aumentó su consumo de alimento mientras que en los grupos Normo-peso y Sobre-peso lo disminuyeron.
Scientific evidence on the characterization of eating behavior indicates that food deprivation situations, such as fasting, the food value increases and alter the feeding pattern. Consequently food consumption increases and therefore caloric intake. The situation worsens when after a deprivation period the preferred foods are unhealthy or consumed in excess becoming tiggers for health problems (Capaldi, 1993; Gottschalk , Libby & Graff , 2000; Velez & Garcia , 2003). The aim of this study was to evaluate the effect of fasting on caloric intake and changing food preferences. This study was conducted with the participation of 9 university students who were classified according to their Body Mass Index (BMI) into three groups: Low-weight, Normo-weight and Over-weight. At the baseline participants were exposed to eight different foods. Same participants during the experimental phase were exposed to a period of fasting, subsequently were exposed to the same foods and record their consumption. Results showed that caloric intake and food preferences were altered after the fasting condition, differential effects among participants were observed. Low-weight group increased their food consumption while Normal-weight and Over-weight groups decreased.