RESUMEN
OBJECTIVE: Insulin resistance (IR) and white adipose tissue (WAT) dysfunction frequently are associated with nonalcoholic fatty liver disease (NAFLD); however, the pathogenic mechanisms contributing to their clustering are not well defined. The aim of this study was to define some nutritional, anthropometric, metabolic, and genetic mechanisms contributing to their clustering. METHODS: Forty-five (20 men, 25 women) patients (age 45.7 ± 11.1 y) with recent diagnosis of NAFLD were grouped according to IR state. Energy balance was assessed using a food questionnaire and indirect calorimetry, and body composition with anthropometry and dual-energy x-ray absorptiometry. Biochemical and hormonal parameters combined with adipose tissue gene expression were determined. Microarray analysis of gene expression was performed in a subset of WAT samples from IR patients (n = 9), in the fasted state, after specific test meals (monounsaturated fatty acid [MUFA], saturated fat [SAT], and carbohydrate-rich) and after being challenged with insulin. RESULTS: IR patients exhibited higher trunk fat to leg fat ratio (P < 0.05) and had a higher ratio of SAT/MUFA fat intake (P < 0.05) than insulin-sensitive (IS) individuals. Deposition of fat in the trunk but not in the leg was directly related to liver enzyme levels (P < 0.05). IR patients also had lower adiponectin serum levels and leptin (LEP) mRNA expression in WAT compared with IS patients (P < 0.01 and P < 0.05, respectively). Microarray analysis after insulin challenge confirmed that insulin treatment induces the expression of PPARG gene and LEP and decreases GCGR gene (P < 0.05 for all) in WAT. No changes in these genes were observed in the postprandial state induced after the acute effect of specific diets. CONCLUSIONS: Patients exhibiting NAFLD and IR had preferential central fat deposition directly related to their serum alanine aminotransferase levels. These patients showed peripheral adipose tissue dysfunction and exhibited inappropriately low LEP biosynthesis that could be partially restored after anabolic conditions induced by insulin signaling.
Asunto(s)
Tejido Adiposo Blanco/metabolismo , Hígado Graso/genética , Conducta Alimentaria , Expresión Génica , Resistencia a la Insulina/genética , Obesidad Abdominal/genética , Absorciometría de Fotón , Adiponectina/sangre , Adulto , Composición Corporal , Índice de Masa Corporal , Estudios Cruzados , Carbohidratos de la Dieta/administración & dosificación , Metabolismo Energético , Ácidos Grasos/administración & dosificación , Ácidos Grasos Monoinsaturados/administración & dosificación , Hígado Graso/dietoterapia , Femenino , Humanos , Insulina/sangre , Interleucina-6/sangre , Leptina/sangre , Masculino , Persona de Mediana Edad , Enfermedad del Hígado Graso no Alcohólico , Estado Nutricional , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ensayos Clínicos Controlados Aleatorios como Asunto , Encuestas y Cuestionarios , Factor de Necrosis Tumoral alfa/sangreRESUMEN
Phantom-limb pain (PLP) is a phenomenon that may appear among people with amputation. Some studies reveal that 70% of people with amputation experience PLP years postamputation. There is a lack of scientific evidence about the cause of PLP. It has been hypothesized that the autonomic nervous system (ANS) could be involved in the mechanism that triggers PLP, but this hypothesis remains unclear. The aim of this study was to correlate ANS function, through heart rate variability (HRV) analysis, with PLP in adult males with amputation. The study population comprised 35 subjects, with 27 reporting PLP often or always. The rest of the subjects did not report any PLP. In order to calculate linear and nonlinear parameters of HRV, all subjects underwent 10 min of resting heart rate monitoring. The study did not find correlations between HRV parameters and PLP. Most of the subjects showed decreased values in linear parameters of HRV while nonlinear values were normal. HRV is not implicated in PLP. Linear and nonlinear methods for HRV analysis might reflect different physiological phenomena; while linear values place people with amputation at cardiovascular risk, nonlinear values indicate normality.