Small, dense low-density lipoprotein and C-reactive protein in obese subjects with and without other criteria for the metabolic syndrome

Although obesity is an important cardiovascular risk factor, growing evidence shows that a substantial portion of obese subjects can be considered metabolically healthy but obese (MHO). However the extent to which obese subjects manifest small, dense low-density lipoprotein (LDL) particles without other characteristics of the metabolic syndrome (MS) remains unknown. The purpose of this study was to determine the difference between MHO (only meeting the obesity criteria) and obese subjects meeting all the criteria for the MS with regard to LDL size and high-sensitivity C-reactive protein (hs-CRP), as a biomarker of inflammation. Two hundred obese subjects (168 women, mean age 36.5 ± 5 years [range, 20–60]; mean body mass index [BMI; calculated as kg/m2] 39 ± 5 [range, 30–80.4]) were studied for LDL particles size and hs-CRP levels. Of 200 enrolled obese subjects, 55 were defined MHO subjects meeting only obesity criteria. The other 145 met all five criteria and were defined as having MS. Although MHO and MS subjects had similar BMI, MHO subjects had a lower percentage of small LDL particles (8% vs 29%, P < 0.001), higher average LDL diameter (274 ± 5 vs 270 ± 7 Å, P < 0.001), and lower hs-CRP levels (P < 0.05) than MS patients. The major finding of this study is that MHO subjects compared to equally obese subjects meeting the criteria of the MS have statistically significant differences in size of LDL and concentration of hs-CRP. However, the absolute differences are very small and of uncertain clinical significance

Relation between epicardial adipose tissue and left ventricular mass

Visceral adiposity is a cardiovascular risk factor of growing interest. This study sought to evaluate the hypothesis of a relation between epicardial adipose tissue, the visceral adipose tissue deposited around the heart, and left ventricular morphology in healthy subjects with a wide range of adiposity. We found for the first time that an increase in epicardial fat is significantly related to an increase in left ventricular mass

Prevalence of uncomplicated obesity in an Italian obese population

The existence of healthy obese subjects has been suggested but not clearly reported. We sought to address the prevalence of uncomplicated obesity and adverse risk factors in a large Italian obese population. This was a cross-sectional study of a population of consecutive Italian obese subjects. We studied 681 obese subjects (514 women and 167 men), with a mean age of 41.1+/-13.9 years (range, 16 to 77 years), mean BMI of 40.2+/-7.6 kg/m2 (range, 30 to 89.8 kg/m2), and a history of obesity for 20.5+/-7 years (range, 10.5 to 30 years). Anthropometric, metabolic, cardiac, and obesity-related risk factors were evaluated. The prevalence of uncomplicated subjects was 27.5%, independent of BMI and duration of obesity. The youngest group of obese subjects showed a higher, but not statistically significantly higher, prevalence of uncomplicated obesity. No statistical difference for the prevalence of impaired fasting glucose, glucose intolerance, high triglycerides, high total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol among BMI categories (from mild to extremely severe obesity degree) was found. Obese subjects with BMI>50 kg/m2 showed a higher prevalence of high blood pressure only when they were compared with the group with a BMI of 30 to 35 kg/m2 (p40 kg/m2 showed a higher prevalence of hyperinsulinemia than subjects with BMI 30 to 35 kg/m2 (p<0.01). This study shows that a substantial part of an Italian obese population has uncomplicated obesity, and the prevalence of adverse risk factors in this sample is unexpectedly low and partially independent of obesity degree. Uncomplicated obesity could represent a well-defined clinical entity

Adapted changes in left ventricular structure and function in severe uncomplicated obesity

A massive amount of fat tissue, as that observed in obese subjects with BMI over 50 kg/m(2), could affect cardiac morphology and performance, but few data on this issue are available. We sought to evaluate cardiac structure and function in uncomplicated severely obese subjects. We studied 55 uncomplicated severely obese patients, 40 women, 15 men, mean age 35.5 +/- 10.2 years, BMI 51.2 +/- 8.8 kg/m(2), range 43 to 81 kg/m(2), with a history of fat excess of at least 10 years, and 55 age-matched normal-weight subjects (40 women, 15 men, mean BMI 23.8 +/- 1.2 kg/m(2)) as a control group. Each subject underwent an echocardiogram to evaluate left ventricular (LV) mass and geometry and systolic and diastolic function. Severely obese subjects showed greater LV mass and indexed LV mass than normal-weight subjects (p or = 50 kg/m(2) and those with BMI or = 50 kg/m(2) and those with BMI < or = 50 kg/m(2) was seen. Our data show that uncomplicated severe obesity, despite the massive fat tissue amount, is associated largely with adapted and appropriate changes in cardiac structure and function

Serum BDNF Levels Are Reduced in Patients with Disorders of Consciousness and Are Not Modified by Verticalization with Robot-Assisted Lower-Limb Training

Little is known about plastic changes occurring in the brains of patients with severe disorders of consciousness (DOCs) caused by acute brain injuries at rest and during rehabilitative treatment. Brain-derived neurotrophic factor (BDNF) is a neurotrophin involved in neurogenesis and synaptic plasticity whose production is powerfully modulated by physical exercise. In this study, we compared serum BDNF levels in 18 patients with unresponsive wakefulness syndrome (UWS) and in a minimally conscious state (MCS) with those in 16 sex- and age-matched healthy controls. In 12 patients, serum BDNF levels before and after verticalization with ErigoPro robot-assisted lower-limb training were compared. Serum BDNF levels were significantly lower in patients (median, 1141 pg/ml; 25th and 75th percentiles, 1016 and 1704 pg/ml) than in controls (median, 2450 pg/ml; 25th and 75th percentiles, 2100 and 2875 pg/ml; p<0.001). BDNF levels measured before and after verticalization with robot-assisted lower-limb training did not change (p=0.5). Moreover, BDNF levels did not differ between patients with UWS and MCS (p=0.2), or between patients with traumatic and nontraumatic brain injuries (p=0.6). BDNF level correlated positively with the time since brain injury (p=0.025). In conclusion, serum BDNF levels are reduced in patients with UWS and MCS and cannot be improved by verticalization associated with passive lower-limb training. Additional studies are needed to better understand the mechanisms underlying BDNF reduction in patients with DOCs and to determine the best rehabilitative strategies to promote restorative plastic changes in these patients

Non-invasive evaluation of endothelial dysfunction in uncomplicated obesity: Relationship with insulin resistance

Obesity is associated with increased cardiovascular morbidity and amortality. Endothelial dysfunction, involved in the pathogenesis of cardiovascular events, has been demonstrated in obese patients with invasive techniques requiring artery catheterization. The aim of our investigation was to evaluate, with a non-invasive method readily employable on clinical grounds, impaired vasodilatation and its relationship with insulin resistance in uncomplicated obesity. 15 uncomplicated obese subjects (BM I = 36.6 +/- 3.2) and 10 lean controls (BMI = 22.9 +/- 1.25) were enrolled in this study. All subjects underwent measurement of endothelium-dependent (FBFr) vasodilatation by forearm venous occlusion pletysmography after increasing times of ischemia, and measurement of insulin sensitivity by the euglycemic hyperinsulinemic clamp technique (M index), by fasting glucose and insulin (HOMA-IR) and by oral glucose tolerance test (ISI index). Endothelium-independent (N-FBFr) vasodilatation was assessed as well. The FBFr was markedly blunted in obese patients versus lean controls (30 s: 2.12 +/- 0.34 vs. 3.63 +/- 0.22, P < 0.01; 60 s: 2.34 +/- 0.42 vs. 3.82 +/- 0.53, P < 0.01; 180 s: 3.20 +/- 0.45 vs. 7.15 +/- 0.35, P < 0.01; 300 s: 4.08 +/- 0.94 vs. 14.1 +/- 0.82, P < 0.001). The N-FBFr was not different in the two groups. High correlation was found between M index and FBFr at all ischemia times. HOMA-IR and ISI were not related with FBFr. The non-invasive evaluation of endothelial dysfunction by a simple and reliable method based on venous occlusive plethysmography shows high correlation between impaired endothelium-dependent vasodilatation and insulin resistance in uncomplicated obesity. This non-invasive test of endothelial function may be routinely performed in the assessment of cardiovascular risk in uncomplicated obesity. (c) 2005 Elsevier Inc. All rights reserved

Influence of excess fat on cardiac morphology and function: study in uncomplicated obesity

To evaluate whether or not "uncomplicated" obesity (without associated comorbidities) is really associated with cardiac abnormalities. We evaluated cardiac parameters in obese subjects with long-term obesity, normal glucose tolerance, normal blood pressure, and regular plasma lipids. We selected 75 obese patients [body mass index (BMI) >30 kg/m(2)], who included 58 women and 17 men (mean age, 33.7 +/- 11.9 years; BMI, 37.8 +/- 5.5 kg/m(2)) with a > or =10-year history of excess fat, and 60 age-matched normal-weight controls, who included 47 women and 13 men (mean age, 32.7 +/- 10.4 years; BMI, 23.1 +/- 1.4 kg/m(2)). Each subject underwent an oral glucose tolerance test to exclude impaired glucose tolerance or diabetes mellitus, bioelectrical impedance analysis to calculate fat mass and fat-free mass, and echocardiography. Obese patients presented diastolic function impairment, hyperkinetic systole, and greater aortic root and left atrium compared with normal subjects. No statistically significant differences between obese subjects and normal subjects were found in indexed left ventricular mass (LVM/body surface area, LVM/height(2.7), and LVM/fat-free mass(kg)), and no changes in left ventricular geometry were observed. No statistically significant differences in cardiac parameters between extreme (BMI > 40 kg/m(2)) and mild obesity (BMI < 35 kg/m(2)) were observed. In conclusion, our data showed that obesity, in the absence of glucose intolerance, hypertension, and dyslipidemia, seems to be associated only with an impairment of diastolic function and hyperkinetic systole, and not with left ventricular hypertrophy

Epicardial fat from echocardiography: a new method for visceral adipose tissue prediction

To validate transthoracic echocardiography as an easy and reliable imaging method for visceral adipose tissue (VAT) prediction. VAT is recognized as an important indicator of high cardiovascular and metabolic risk. Several methods are applied to estimate VAT, with different results. We selected 60 healthy subjects (29 women, 31 men, 49.5 +/- 16.2 years) with a wide range of body mass indexes. Each subject underwent transthoracic echocardiogram and magnetic resonance imaging (MRI) to measure epicardial fat thickness on the right ventricle. Measurements of epicardial adipose tissue thickness were obtained from the same echocardiographic and MRI views and points. MRI was also used to measure VAT cross-sectional areas at the level of L4 to L5. Anthropometric indexes were also measured. Subjects with predominant visceral fat accumulation showed higher epicardial adipose tissue thickness than subjects with predominant peripheral fat distribution: 9.97 +/- 2.88 vs. 4.34 +/- 1.98 (p = 0.005) and 7.19 +/- 2.74 vs. 3.43 +/- 1.64 (p = 0.004) in men and women, respectively. Simple linear regression analysis showed an excellent correlation between epicardial adipose tissue and waist circumference (r = 0.895, p = 0.01) and MRI abdominal VAT (r = 0.864, p = 0.01). Multiple regression analysis showed that epicardial adipose tissue thickness (r(2) = 0.442, p = 0.02) was the strongest independent variable correlated to MRI VAT. Bland test confirmed the good agreement between the two methods. Epicardial adipose tissue showed a strong correlation with anthropometric and imaging measurements of VAT. Hence, transthoracic echocardiography could be an easy and reliable imaging method for VAT prediction

Relationship of insulin sensitivity and left ventricular mass in uncomplicated obesity

Objective: We studied uncomplicated obesity as a model to evaluate the influence of insulin sensitivity per se on left ventricular mass (LVM) and geometry. Research Methods and Procedures: We selected 50 obese subjects (BMI > 30 kg/m2; 38 women and 12 men; mean age, 38.4 ± 10 years; BMI, 36.4 ± 10.5 kg/m2) with normal blood pressure, glucose tolerance, and plasmatic lipid levels. Thirty lean subjects formed the control group. Each subject underwent euglycemic insulin clamp (7 pmol/min per kg) to evaluate whole body glucose use (M index) and echocardiogram to calculate LVM and indexed LVM. Results: Insulin-resistant obese subjects had higher LVM, LVM/h2,7, LVM/body surface area, and LVM/fat-free masskg (p = 0.001; p = <0.001 p = 0.001, and p = 0.04, respectively) than obese subjects with normal insulin sensitivity. Multivariate regression analysis showed that M index was the strongest independent correlate of LVM (r 2 = 0.34; p = 0.03). Discussion: Our findings showed that insulin resistance, in uncomplicated obesity, is associated with an increased LVM and precocious changes of left ventricular geometry, whereas preserved insulin sensitivity is not associated with increased LVM. Copyright © 2003 NAASO

Acute insulin infusion decreases plasma ghrelin levels in uncomplicated obesity

Background: Plasma ghrelin levels have been shown to decrease after insulin infusion in lean subjects. Nevertheless, the mechanism of the suggested inhibitory effect of insulin on ghrelin is still unclear and no data about the effect of acute insulin infusion on plasma ghrelin concentration in obese subjects are available. Objective: We sight to evaluate plasma ghrelin concentration during an hyperinsulinemic euglycemic clamp in uncomplicated obese subjects. Methods: 35 uncomplicated obese subjects, body mass index (BMI) 43.3 +/- 10.1 kg/m(2), 33 women and 2 men, mean age 34.9 +/- 10, with a history of excess fat of at least 10 years underwent euglycemic hyperinsulinemic clamp. Blood samples for ghrelin were performed at baseline and steady state of euglycemic insulin clamp. Results: Ghrelin concentrations decreased over time to 10.6 +/- 15% (range 2-39%) of baseline, from a mean of 205.53 +/- 93.79 pg/ml to 179.03 +/- 70.43 pg/ml during the clamp (95% Cl, 10.69 to 36.44, P<0.01). In a univariate linear regression analysis baseline plasma ghrelin levels were inversely correlated to BMI (r = - 0.564, P = 0.04). A linear positive trend between whole body glucose utilization (M-FFMkg index) and ghrelin reduction during the clamp was found (chi(2) 3.05, p = 0.05). Conclusions: Our data seem to suggest that hyperinsulinemia during a euglycemic clamp is able to suppress plasma ghrelin concentrations in uncomplicated obesity. This effect appears to be positively related to insulin sensitivity. (C) 2004 Elsevier B.V. All rights reserved