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Frida Leonetti

Publications and source records attributed to Frida Leonetti.

30 records · Page 2Linked to original sources

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

OBJECTIVE: 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. RESEARCH METHODS AND PROCEDURES: 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. RESULTS: 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. DISCUSSION: 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.

Adipose Tissue↗

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/m(2); 38 women and 12 men; mean age, 38.4 +/- 10 years; BMI, 36.4 +/- 10.5 kg/m(2)) 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/h(2.7), LVM/body surface area, and LVM/fat-free mass(kg) (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.

Adult↗

Glucose homeostasis in acromegaly: effects of long-acting somatostatin analogues treatment.

OBJECTIVE: Acromegaly is a syndrome with a high risk of impaired glucose tolerance (IGT) and diabetes mellitus (DM). Somatostatin analogues, which are used for medical treatment of acromegaly, may exert different hormonal effects on glucose homeostasis. Twenty-four active acromegalic patients were studied in order to determine the long-term effects of octreotide-LAR and SR-lanreotide on insulin sensitivity and carbohydrate metabolism. DESIGN: Prospective study. PATIENTS: We studied 24 patients with active acromegaly, 11 males and 13 females, aged 50.7 +/- 12.7 years, body mass index (BMI) 30.1 +/- 4.8 (kg/m2). MEASUREMENTS: All patients underwent an oral glucose tolerance test (OGTT) and 12 also had an euglycaemic hyperinsulinaemic clamp. All patients were evaluated at baseline and after 6 months of somatostatin analogues therapy. RESULTS: Acromegalic patients showed low M-values in respect to the control group at baseline (P<0.05), followed by a significant improvement after 6 months of therapy (P<0.005 vs. baseline). Serum glucose levels at 120 min during OGTT worsened (P<0.05) during somatostatin analogs therapy in patients with normal glucose tolerance, but not in those with impaired glucose tolerance or diabetes mellitus. This was associated with a reduced (P<0.05) and 30 min delayed insulin secretion during OGTT. Also, HbA1c significantly deteriorated in all subjects after treatment (4.7 +/- 0.6% and 5.1 +/- 0.5%, basal and after six months, respectively, P<0.005). CONCLUSION: In acromegalic patients, somatostatin analogues treatment reduces insulin resistance, and also impairs insulin secretion. This may suggest that the use of oral secretagogue hypoglycaemic agents and/or insulin therapy should be considered rather than insulin sensitizers, as the treatment of choice in acromegalic patients who develop frank hyperglycaemia during somatostatin analogues therapy.

Acromegaly↗

Different plasma ghrelin levels after laparoscopic gastric bypass and adjustable gastric banding in morbid obese subjects.

Gastric bypass has been reported to be associated with markedly suppressed plasma ghrelin levels, suggesting that it is one of the possible weight-reducing factors related to this procedure. The aim of this study was the evaluation of plasma ghrelin levels in patients who had undergone laparoscopic Roux-en-Y gastric bypass (LRYGBP) and laparoscopic adjustable silicone gastric banding (LASGB). Normoweight, obese subjects and patients who had undergone total gastrectomy were used as controls. In this cross-sectional study, we selected 10 subjects who underwent LASGB, 11 subjects with LRYGBP, 10 obese subjects, eight patients with total gastrectomy, and eight normoweight subjects. Plasma ghrelin, insulin, and glucose profiles were determined before and after breakfast and lunch. Obese subjects showed a ghrelin plasma level significantly lower than normoweight subjects (407.3 +/- 21.6 vs. 813 +/- 72.4 pg/ml, P < 0.01). Patients with LRYGBP showed baseline ghrelin levels lower than LASGB (213.5 +/- 73.9 vs. 314.2 +/- 84.3 pg/ml, P = 0.04). Both groups of patients who underwent bariatric surgical procedures also had ghrelin lower than normoweight and obese subjects (P < 0.01 and P < 0.05, respectively). Patients with total gastrectomy showed plasmatic ghrelin levels extremely lower than those in all other groups (32.6 +/- 18.7 pg/ml, P < 0.001 for all). The ghrelin profile in both groups of subjects who underwent LRYGBP and LASGB did not show any meal-related changes as observed in obese and normoweight control groups. Significant difference in plasma ghrelin levels between LRYGBP and LASGB was found, suggesting that both procedures could induce weight loss by different mechanisms in which ghrelin could be involved.

Adipose Tissue↗

Echocardiographic epicardial adipose tissue is related to anthropometric and clinical parameters of metabolic syndrome: a new indicator of cardiovascular risk.

Metabolic syndrome is related to multiple cardiovascular risk factors. Visceral adipose tissue (VAT) plays a key role in metabolic syndrome. Easy detection of VAT could be an important tool to increase knowledge of metabolic syndrome. The objective of this study was to study the relationship of echocardiographic epicardial adipose tissue to anthropometric and clinical parameters of metabolic syndrome. We selected 72 consecutive subjects, 46.5 +/- 17.4 yr of age, with a body mass index between 22 and 47 kg/m(2). Each subject underwent transthoracic echocardiogram to measure epicardial fat thickness on right ventricle and magnetic resonance imaging to calculate visceral adipose tissue. Anthropometric, metabolic, and cardiac parameters were also evaluated. Echocardiographic epicardial adipose tissue showed a very good correlation with magnetic resonance imaging abdominal VAT and epicardial fat measurement (Bland-Altman plot and linear regression). Multiple regression analysis showed that waist circumference (r(2) = 0.428; P = 0.01), diastolic blood pressure (r(2) = 0. 387; P = 0.02), and fasting insulin (r(2) = 0.387; P = 0.03) were the strongest independent variables correlated with epicardial adipose tissue. Echocardiographic epicardial adipose tissue could be applied as an easy and reliable imaging indicator of VAT and cardiovascular risk.

Adipose Tissue↗

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

OBJECTIVE: To evaluate whether or not "uncomplicated" obesity (without associated comorbidities) is really associated with cardiac abnormalities. RESEARCH METHODS AND PROCEDURES: 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. RESULTS: 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. DISCUSSION: 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.

Adipose Tissue↗

Relationship between plasma free fatty acids and uncoupling protein-3 gene expression in skeletal muscle of obese subjects: in vitro evidence of a causal link.

OBJECTIVE: To investigate whether skeletal muscle uncoupling protein-2 (UCP2) and uncoupling protein-3 (UCP3) gene expression is altered in massive obesity and whether it correlates with in vivo insulin sensitivity and with metabolic and hormonal status. DESIGN: Quantification of UCP2 and UCP3 gene expression in skeletal muscle of obese and lean subjects displaying different degrees of insulin sensitivity. PATIENTS: Fourteen obese and 10 age- and sex-matched healthy control subjects with a mean body mass index (BMI) of 43.6 +/- 1.4 and 22.8 +/- 1.8 (+/- SEM), respectively. MEASUREMENTS: Insulin sensitivity by glucose clamp, body composition by bio-impedance, fasting plasma glucose, insulin, leptin and free fatty acids (FFA). Skeletal muscle UCP2 and UCP3 mRNA levels by quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: No significant differences in UCP2 or UCP3 mRNA levels were found between obese and control subjects. No significant correlation was observed, in both groups, between UCP2 or UCP3 mRNA levels and both anthropometrical and metabolic parameters. In contrast, a highly significant correlation was observed between skeletal muscle UCP3, but not UCP2, mRNA levels and plasma FFA in the obese, but not in the lean, group. Furthermore, exposure of human myocytes to FFA for 24 h strongly induced both UCP3 and peroxisome proliferator-activated receptor-gamma (PPARgamma) but not UCP2 gene expression. CONCLUSIONS: FFA levels correlate strongly with skeletal muscle UCP3 mRNA levels in obese, but not in lean, subjects; in addition, in human myocytes, high FFA concentrations promote UCP3 expression. Our studies therefore provide evidence that supports a role for increased plasma FFA concentrations in the regulation of human skeletal muscle UCP3 gene expression.

Adult↗

Human resistin gene, obesity, and type 2 diabetes: mutation analysis and population study.

The hormone resistin has been suggested to link obesity to type 2 diabetes by modulating steps in the insulin-signaling pathway and inducing insulin resistance. Thus, the resistin gene represents a potential candidate for the etiology of insulin resistance and type 2 diabetes. In this study, we analyzed the coding sequence of the three exons of the resistin gene, together with its 5' regulatory region and 3' untranslated region (UTR), by single-strand conformation polymorphism (SSCP) in 58 type 2 diabetic subjects, 59 obese subjects, and 60 normal subjects. Only one sequence variant was detected in the resistin gene. Sequencing of this variant revealed the presence of a single nucleotide substitution (SNP) in the 3'-UTR of exon 3 (G1326A) [corrected]. Because 3'-UTR SNPs have been shown to affect gene expression, we examined the frequency of this SNP in 591 subjects (198 obese subjects, 207 diabetic subjects, and 186 control subjects) by PCR amplification and BseRI digestion. No significant association was found between the G1326A [corrected] variant and diabetes and obesity. Comparison of clinical and metabolic parameters between G1326A [corrected] carriers and noncarriers again showed no significant difference. In conclusion, our data suggest that genetic defects of the resistin gene are unlikely to play a role in the etiology of these common disorders in our population.

3' Untranslated Regions↗

Continuous subcutaneous glucose monitoring in diabetic patients: a multicenter analysis.

OBJECTIVE: To evaluate the accuracy of a new subcutaneous glucose sensor (Glucoday; A. Menarini Diagnostics) compared with venous blood glucose measurement in type 1 and type 2 diabetic patients. RESEARCH DESIGN: A multicenter study was performed in 70 diabetic patients. A microdialysis fiber was inserted subcutaneously into the periumbelical region and perfused with a buffer solution. Glucose concentrations in the dialysate were then measured every 3 min by the glucose sensor over a 24-h period, during which nine venous blood samples were also collected throughout the day. RESULTS: Both the insertion of the fiber and the wearing of the device were well tolerated by the patients. Subcutaneous glucose levels were well correlated with venous glucose measurements (r = 0.9, P < 0.001) over a wide range (40-400 mg/dl) for up to 24 h, with a single-point calibration. An analysis of 381 data pairs showed a linear relationship between the GlucoDay and serial venous blood glucose levels, and 97% of the data fell in the A and B regions of the error grid analysis. Percentage bias between the GlucoDay and the blood venous levels was -2.0% in the hypoglycemic range (<70 mg/dl), 6.9% in the euglycemic range (70-180 mg/dl), and 11.2% in the hyperglycemic range (>180 mg/dl). CONCLUSIONS: The GlucoDay system demonstrated high reliability and reported values that closely agreed with venous blood glucose measurements. The system was well tolerated and thus constitutes a relatively easy method to monitor glucose excursions in diabetic patients.

Adult↗

Exercise training can modify the natural history of diabetic peripheral neuropathy.

BACKGROUND: Diabetes is the most important cause of peripheral neuropathy (DPN). No definitive treatment for DPN has been established, and very few data on the role of exercise training on DPN have been reported. AIM OF THE STUDY: We sought to examine the effects of long-term exercise training on the development of DPN in both Types 1 and 2 diabetic patients. PARTICIPANTS AND METHODS: Seventy-eight diabetic patients without signs and symptoms of peripheral DPN were enrolled, randomized, and subdivided in two groups: 31 diabetic participants [15 f, 16 m; 49+/-15.5 years old; body mass index (BMI)=27.9+/-4.7], who performed a prescribed and supervised 4 h/week brisk walking on a treadmill at 50% to 85% of the heart rate reserve (exercise group: EXE), and a control group of 47 diabetic participants (CON; 24 f, 23 m; 52.9+/-13.4 years old; BMI=30.9+/-8.4). Vibration perception threshold (VPT), nerve distal latency (DL), nerve conduction velocity (NCV), and nerve action potential amplitude (NAPA) in the lower limbs were measured. RESULTS: We found significant differences on Delta (delta) in NCV for both peroneal and sural motor nerve between the EXE and CON groups during the study period (P<.001, for both). The percentage of diabetic patients that developed motor neuropathy and sensory neuropathy during the 4 years of the study was significantly higher in the CON than the EXE group (17% vs. 0.0%, P<.05, and 29.8% vs. 6.45%, P<.05, respectively). In addition, the percentage of diabetic patients who developed increased VPT (25 V) during the study was significantly higher in the CON than the EXE group (21.3% vs. 12.9%, P<.05). Change on Hallux VPT from baseline to the end of the study was significantly different between the EXE and CON groups (P<.05); no significant change in Malleolus VPT between the two groups occurred. CONCLUSIONS: This study suggests, for the first time, that long-term aerobic exercise training can prevent the onset or modify the natural history of DPN.

Adult↗