Showing papers by "Antonio Esposito published in 2007"

Habitual Physical Activity Is Associated With Intrahepatic Fat Content in Humans

Abstract: OBJECTIVE —Fatty liver may be involved in the pathogenesis of type 2 diabetes. Physical exercise is a tool to improve insulin sensitivity, but little is known about its effect on intrahepatic fat (IHF) content. The purpose of this study was to examine the association of habitual physical activity, insulin resistance, and adiponectin with IHF content. RESEARCH DESIGN AND METHODS —Participants were 191 (77 female and 114 male) apparently healthy, nonalcoholic individuals (aged 19–62 years; BMI 17.0–35.5 kg/m2). IHF content was assessed in a quantitative fashion and noninvasively as a continuous variable by means of 1H magnetic resonance spectroscopy (MRS), and habitual physical activity was assessed by means of a questionnaire. Fatty liver was defined as IHF content of >5% wet weight, and insulin sensitivity was estimated using the computer homeostasis model assessment (HOMA)-2 indexes. RESULTS —A reduced prevalence of fatty liver in the quartile of the most physically active individuals (25, 11, 25, and 2% in quartile 1, 2, 3, and 4, respectively; χ2 = 15.63; P = 0.001) was found along with an inverse correlation between the physical activity index and the IHF content when plotted as continuous variables (Pearson’s r = −0.27; P < 0.000). This association was not attenuated when adjusted for age, sex, BMI, HOMA-2, and adiponectin (partial correlation r = −0.25; P < 0.001). CONCLUSIONS —This study demonstrated that a higher level of habitual physical activity is associated with a lower IHF content and suggested that this relationship may be due to the effect of exercise per se.

Abnormal left ventricular energy metabolism in obese men with preserved systolic and diastolic functions is associated with insulin resistance.

Abstract: OBJECTIVE —Perturbations in cardiac energy metabolism might represent early alterations in diabetes preceding functional and pathological changes. We evaluated left ventricular (LV) structure/geometry and function in relation to energy metabolism and cardiovascular risk factors in overweight/obese men using magnetic resonance techniques. RESEARCH DESIGN AND METHODS —We studied 81 healthy men (aged 22–55 years, with BMI between 19 and 35 kg/m2) by means of cardiac magnetic resonance imaging and 31P-magnetic resonance spectroscopy in the resting and fasted conditions and stratified them in quartiles of BMI (cut offs: 23.2, 25.5 and 29.0 kg/m2). RESULTS —LV mass increased across quartiles of BMI; meanwhile, the volumes did not differ. Parameters of LV systolic and diastolic function were not different among quartiles. The phosphocreatine-to-ATP ratio was reduced across increasing quartiles of mean ± SD BMI (2.25 ± 0.52, 1.89 ± 0.26, 1.99 ± 0.38, and 1.79 ± 0.29; P < 0.006) in association with insulin sensitivity (computer homeostasis model assessment 2 model); this relation was independent of age, BMI, blood pressure, wall mass, HDL cholesterol, triglycerides, smoking habits, and metabolic syndrome. CONCLUSIONS —Abnormal LV energy metabolism was detectable in obese men in the presence of normal function, supporting the hypothesis that metabolic remodeling in insulin resistant states precedes functional and structural/geometrical remodeling of the heart regardless of the onset of overt hyperglycemia.

Serum retinol-binding protein-4, leptin, and adiponectin concentrations are related to ectopic fat accumulation.

Abstract: Context: Serum retinol-binding protein 4 (RBP-4), leptin, and adiponectin concentrations identify insulin resistance in varied conditions, but their relationships with insulin sensitivity and ectopic fat accumulation are unclear. Objective: Our objective was to establish how these adipokines are related with intramyocellular lipid (IMCL) and intrahepatic lipid (IHL) content. Design and Setting: We assessed retrospectively serum fasting RBP-4 concentrations in 1) 53 nondiabetic individuals in which insulin sensitivity and IMCL content were assessed by means of the insulin clamp and of 1 H magnetic resonance spectroscopy of the calf muscles, and 2) 140 nondiabetic individuals in which insulin sensitivity and the IHL content were assessed by means of the updated homeostasis model assessment and of 1 H magnetic resonance spectroscopy. In both experiments, serum leptin and adiponectin concentrations were measured. Results: Fasting serum RBP-4, adiponectin, and leptin were associated with peripheral insulin sensitivity, were abnormal in the first-degreerelativesoftype2diabeticparents,andcorrelatedwith the soleus IMCL content and with the IHL content. The association of RBP-4 and adiponectin with insulin sensitivity was age, sex, and body mass index independent, but stepwise regression analysis suggested that RBP-4, but not adiponectin and leptin, was independently associated with insulin sensitivity. Adiponectin was independently associated with the IHL content, RBP-4, and leptin with the soleus IMCL content.

Myocarditis Associated with Clozapine Studied by Cardiovascular Magnetic Resonance

Abstract: Clozapine is a neuroleptic agent which has been classified as atypical due to its peculiar pharmacological characteristics; many clinical trials have proved its efficacy in schizophrenic patients which are refractory to typical neuroleptics (1,2). Unfortunately, clozapine administration may be associated with severe cardiac side effects, in particular cardiomyopathy and myocarditis (2-8). Myocarditis is an inflammatory disease of the myocardium which is most frequently caused by infectious agents, but may also be associated with various pharmacological therapies (9-12). We report the first case of clozapine-induced myocarditis documented by late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR).