RESUMEN
BACKGROUND AND AIMS: The role of the different factors associated with fatty liver is still poorly defined. We evaluated the relationships between liver fat content (LF) and metabolic, inflammatory and nutritional factors in a homogeneous cohort of individuals at high cardio-metabolic risk. METHODS AND RESULTS: In 70 individuals with high waist circumference and at least one more criterion for metabolic syndrome enrolled in a nutritional intervention study, LF was evaluated at baseline by hepatic/renal echo intensity ratio (H/R), together with dietary habits (7-day dietary record), insulin sensitivity and ß-cell function (fasting and OGTT-derived indices), fasting and postprandial plasma GLP-1 and lipoproteins, and plasma inflammatory markers. H/R correlated positively with fasting and OGTT plasma glucose and insulin concentrations, HOMA-IR and ß-cell function, and IL-4, IL-17, IFN-γ, TNF-α, FGF and GCSF plasma concentrations (p < 0.05 for all), and negatively with insulin sensitivity (OGIS), dietary, polyphenols and fiber (p < 0.05 for all). By multiple stepwise regression analysis, the best predictors of H/R were OGIS (ß = -0.352 p = 0.001), postprandial GLP-1 (ß = -0.344; p = 0.001), HDL-cholesterol (ß = -0.323; p = 0.002) and IFN-γ (ß = 0.205; p = 0.036). CONCLUSION: A comprehensive evaluation of factors associated with liver fat, in a homogeneous population at high cardio-metabolic risk, indicated a pathogenic combination of the same pathways underlying the atherosclerotic process, namely whole body insulin sensitivity and inflammation. The higher predictive value of postprandial variables suggests that liver fat is essentially a postprandial phenomenon, with a relevant role possibly played by GLP-1. REGISTRATION NUMBER FOR CLINICAL TRIALS: NCT01154478.
Asunto(s)
Inmunidad Adaptativa , Enfermedades Cardiovasculares/etiología , Péptido 1 Similar al Glucagón/sangre , Resistencia a la Insulina , Hígado/metabolismo , Síndrome Metabólico/etiología , Enfermedad del Hígado Graso no Alcohólico/etiología , Periodo Posprandial , Adulto , Anciano , Biomarcadores/sangre , Glucemia/metabolismo , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/inmunología , Enfermedades Cardiovasculares/prevención & control , HDL-Colesterol/sangre , Estudios Transversales , Registros de Dieta , Conducta Alimentaria , Femenino , Humanos , Mediadores de Inflamación/sangre , Insulina/sangre , Interferón gamma/sangre , Italia , Hígado/diagnóstico por imagen , Hígado/inmunología , Hígado/fisiopatología , Masculino , Síndrome Metabólico/sangre , Síndrome Metabólico/dietoterapia , Síndrome Metabólico/inmunología , Persona de Mediana Edad , Análisis Multivariante , Enfermedad del Hígado Graso no Alcohólico/sangre , Enfermedad del Hígado Graso no Alcohólico/dietoterapia , Enfermedad del Hígado Graso no Alcohólico/inmunología , Estado Nutricional , Análisis de Regresión , Medición de Riesgo , Factores de Riesgo , Factores de TiempoRESUMEN
BACKGROUND AND AIM: Until recently, very few intervention studies have investigated the effects of whole-grain cereals on postprandial glucose, insulin and lipid metabolism, and the existing studies have provided mixed results. The objective of this study was to evaluate the effects of a 12-week intervention with either a whole-grain-based or a refined cereal-based diet on postprandial glucose, insulin and lipid metabolism in individuals with metabolic syndrome. METHODS AND RESULTS: Sixty-one men and women age range 40-65 years, with the metabolic syndrome were recruited to participate in this study using a parallel group design. After a 4-week run-in period, participants were randomly assigned to a 12-week diet based on whole-grain products (whole-grain group) or refined cereal products (control group). Blood samples were taken at the beginning and end of the intervention, both fasting and 3 h after a lunch, to measure biochemical parameters. Generalized linear model (GLM) was used for between-group comparisons. Overall, 26 participants in the control group and 28 in the whole-grain group completed the dietary intervention. Drop-outs (five in the control and two in the whole-grain group) did not affect randomization. After 12 weeks, postprandial insulin and triglyceride responses (evaluated as average change 2 and 3 h after the meal, respectively) decreased by 29% and 43%, respectively, in the whole-grain group compared to the run-in period. Postprandial insulin and triglyceride responses were significantly lower at the end of the intervention in the whole-grain group compared to the control group (p = 0.04 and p = 0.05; respectively) whereas there was no change in postprandial response of glucose and other parameters evaluated. CONCLUSIONS: A twelve week whole-grain cereal-based diet, compared to refined cereals, reduced postprandial insulin and triglycerides responses. This finding may have implications for type 2 diabetes risk and cardiovascular disease.