Effect of Octreotide on Neuroenolase Levels in Patients with Small Cell Lung Cancer

Aims and Background

The somatostatin analog octreotide has an antiproliferative effect on small cell lung cancer lines in vitro and in experimental xenograft transplantation systems in vivo. Thus it is worth investigating octreotide activity in the clinical setting.

Methods

We studied the effect of octreotide (200 μg three times a day subcutaneously for seven days) on serum levels of the tumor marker neuroenolase in 13 patients with small cell lung cancer.

Results

A decrease in neuroenolase levels was observed at day 7 during octreotide treatment, with a mean ± SD of 32.6 ± 42.0 ng/ml compared to basal values of 44.4 ± 57.7 ng/ml and to washout values of 50.3 ± 65.7 ng/ml ( P < 0.03).

Conclusions

Our results indicate that octreotide is effective in reducing neuroenolase levels in small cell lung cancer patients. These data suggest a possible role for octreotide in the treatment of this kind of tumor.

Short- and long-term mortality in a prevalent cohort of morbidly obese patients in Italy

BACKGROUND

Morbid obesity has been associated with increased mortality.

AIM OF THE STUDY

We evaluated the risk of short- (2 years) and long-term (10 years) mortality in two consecutive series of Italian morbidly obese patients hospitalized in a Metabolic Unit.

METHODS

The vital status of 569 patients (435 females and 134 males, BMI 44.4 kg/m(2), age 46.1 years), first admitted for clinical treatment in two separate periods (1988 and 1996), was ascertained in 1999.

RESULTS

Twenty-seven deaths were identified and compared with expected deaths according to mortality rates in the Italian population, to estimate the standardized mortality ratio (SMR). In the first two years after admission only 3 deaths were observed and the SMR tended to be reduced (SMR = 0.5, 95 % CI 0.1-1.5). In contrast, the long-term follow-up showed a significantly elevated risk of death (SMR = 1.6, 95 % CI 1.1-2.4).

CONCLUSIONS

The follow-up of this Italian prevalent cohort confirm that morbid obesity is associated with increased mortality. The observed SMR might have been attenuated by inclusion in our study of subjects with relatively good health conditions, who are possibly more representative of the general obese population than subjects affected by important obesity-related complications, observed in other studies. The excess risk was not evident in the first two years after clinical treatment.

Lymphocytes and immunoglobulin patterns across the threshold of severe obesity

The proinflammatory state of metabolic disorders encompasses the alterations in leukocyte counts and acute-phase reactants, and thus, predisposes to acute and chronic cardiovascular events linked to fat accumulation. Leptin is a marker of adiposity and also yields regulatory effects on innate and adaptive immunity; however, its role on the immune function of obese subjects remains to be elucidated. The aim of this study is to determine the influence of obesity and the role of leptin concentrations on lymphocyte counts and immunoglobulin levels as broad markers of immune function. Cross-sectional analysis in 147 obese (64 M, BMI 43 ± 8.1 kg/m(2)) and 111 age- and sex-matched controls (36 M, BMI 22.5 ± 2.6 kg/m(2)) by assessment of peripheral leukocyte counts, immunoglobulin (Ig) A, G, M levels, leptin, glucose and lipid homeostasis, and acute-phase reactants. Compared to controls, all the leukocyte components were significantly increased in obesity (p < 0.0001 for all) except for basophils and eosinophils. While IgA and IgG levels were similar between groups, IgM levels were lower (p < 0.001) in obese individuals. A significant relationship was evident between leptin and leukocyte counts (p < 0.001), with this latter being correlated to insulin resistance, adiposity, and lipid profile. At the stepwise multiple regression analysis, leukocytes were best predicted by leptin (β = 0.43, p < 0.0001) and male gender (β = 0.15, p < 0.05), yet when obesity entered the equation, it acted as an independent predictor of leukocytes (β = 0.51, p < 0.0001). Leptin also acted as a predictor of IgA levels (β = 0.20, p < 0.01). Current results show that IgM levels are significantly decreased in patients with obesity in association to significant increments in leukocyte counts. These latter are markedly correlated to leptin levels, insulin resistance, lipid profile, and adiposity. This circumstance, and the significant correlation seen between leptin and IgA levels, may suggest an indirect intervention of leptin in the immunologic alterations consequent to obesity and related to its cardiovascular risk.

Molecular and morphologic characterization of superficial- and deep-subcutaneous adipose tissue subdivisions in human obesity

OBJECTIVE

Human abdominal subcutaneous white adipose tissue (SAT) is composed of two different subcompartments: a "superficial" SAT (SSAT), located between the skin and a fibrous-fascia plane; and a deeper SAT, located under this fibrous fascia plane, indicated as "deep" SAT (DSAT).

DESIGN AND METHODS

In order to investigate whether SSAT and DSAT have different molecular and morphological features, paired SSAT/DSAT biopsies were collected from 10 female obese patients and used for microarray and morphologic analysis. The stroma-vascular fraction cells were also isolated from both depots and cultured in vitro to assess the lipid accumulation rate.

RESULTS

SSAT and DSAT displayed different patterns of gene expression, mainly for metabolic and inflammatory genes, respectively. Detailed gene expression analysis indicated that several metabolic genes, including adiponectin, are preferentially expressed in SSAT, whereas inflammatory genes are over-expressed in DSAT. Despite a similar lipid accumulation rate in vitro, in vivo SSAT showed a significant adipocyte hypertrophy together with a significantly lower inflammatory infiltration and vascular vessel lumen mean size, when compared to DSAT.

CONCLUSIONS

These data show that, SSAT and DSAT are functionally and morphologically different and emphasize the importance of considering independent these two adipose depots when investigating SAT biology and obesity complications.

Meta-analysis of gene-level associations for rare variants based on single-variant statistics

Meta-analysis of genome-wide association studies (GWASs) has led to the discoveries of many common variants associated with complex human diseases. There is a growing recognition that identifying "causal" rare variants also requires large-scale meta-analysis. The fact that association tests with rare variants are performed at the gene level rather than at the variant level poses unprecedented challenges in the meta-analysis. First, different studies may adopt different gene-level tests, so the results are not compatible. Second, gene-level tests require multivariate statistics (i.e., components of the test statistic and their covariance matrix), which are difficult to obtain. To overcome these challenges, we propose to perform gene-level tests for rare variants by combining the results of single-variant analysis (i.e., p values of association tests and effect estimates) from participating studies. This simple strategy is possible because of an insight that multivariate statistics can be recovered from single-variant statistics, together with the correlation matrix of the single-variant test statistics, which can be estimated from one of the participating studies or from a publicly available database. We show both theoretically and numerically that the proposed meta-analysis approach provides accurate control of the type I error and is as powerful as joint analysis of individual participant data. This approach accommodates any disease phenotype and any study design and produces all commonly used gene-level tests. An application to the GWAS summary results of the Genetic Investigation of ANthropometric Traits (GIANT) consortium reveals rare and low-frequency variants associated with human height. The relevant software is freely available.

Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture

Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.

Serum adiponectin levels in advanced-stage Parkinson's disease patients

Patients with advanced Parkinson's disease (PD) experience body weight loss and reductions in the most common cardiovascular risk factors. At present, the pathogenetic mechanisms involved have not been elucidated. Increased serum concentrations of adiponectin, which possesses antiatherogenic and anti-inflammatory properties, are associated with a reduction in cardiovascular risk. The objective of this study was to determine adiponectin serum concentrations in PD patients. Thirty PD patients underwent a full nutritional status assessment, including the determination of adiponectin serum concentrations. Mean ± SD adiponectin concentrations were 9.59 ± 5.9 μg/mL (interquartile range: 5.92–12.9 μg/mL). In PD patients, adiponectin serum levels were similar to those in normal-weight, healthy, young subjects and significantly higher than that in an aged-matched group of morbidly obese subjects. Further studies are warranted to establish the role of adiponectin in the management of PD patients.

TECNOB Study: Ad Interim Results of a Randomized Controlled Trial of a Multidisciplinary Telecare Intervention for Obese Patients with Type-2 Diabetes

BACKGROUND

Obesity increases the risk of many health complications such as hypertension, coronary heart disease and type 2 diabetes, needs long-lasting treatment for effective results and involves high public and private care-costs. Therefore, it is imperative that enduring and low-cost clinical programs for obesity and related co-morbidities are developed and evaluated. Information and communication technologies (ICT) can help clinicians to deliver treatment in a cost-effective and time-saving manner to a large number of obese individuals with co-morbidities.

OBJECTIVE

To examine ad interim effectiveness of a 12-month multidisciplinary telecare intervention for weight loss provided to obese patients with type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

A single-center randomized controlled trial (TECNOB study) started in December 2008. At present, 72 obese patients with type 2 diabetes have been recruited and randomly allocated to the TECNOB program (n=37) or to a control condition (n=39). However, only 34 participants have completed at least the 3-month follow-up and have been included in this ad interim analysis. 21 out of them have reached also the 6-month follow-up and 13 have achieved the end of the program. Study is still on-going.

INTERVENTION

All participants attended 1-month inpatient intensive program that involved individualized medical care, diet therapy, physical training and brief psychological counseling. At discharge, participants allocated to the TECNOB program were instructed to use a weight-loss web-site, a web-based videoconference tool, a dietary software installed into their cellular phones and an electronic armband measuring daily steps and energy expenditure.

MAIN OUTCOME MEASURES

Weight and disordered eating-related behaviors and cognitions (EDI-2) at entry to hospital, at discharge from hospital, at 3,6 and 12 months.

RESULTS

Ad interim analysis of data from 34 participants showed no statistically significant difference between groups in weight change at any time-point. However, within-group analysis revealed significant reductions of initial weight at discharge from hospital, at 3 months, at 6 months but not at 12 months. Control group had higher scores in Interpersonal distrust at 12 months.

CONCLUSION

This ad interim findings revealed that the effect of the inpatient treatment was high and probably overwhelmed the effect of the TECNOB intervention. Much statistical power and long-term follow-up may enhance the probability to detect the TECNOB effect over and above the great one exerted by the inpatient program.

Rare melanocortin-3 receptor mutations with in vitro functional consequences are associated with human obesity

In contrast to the melanocortin 4 receptor, the possible role of the melanocortin 3 receptor (MC3R) in regulating body weight is still debated. We have previously reported three mutations in the MC3R gene showing association with human obesity, but these results were not confirmed in a study of severe obese North American adults. In this study, we evaluated the entire coding region of MC3R in 839 severely obese subjects and 967 lean controls of Italian and French origin. In vitro functional analysis of the mutations detected was also performed. The total prevalence of rare MC3R variants was not significantly different in obese subjects when compared with controls (P= 0.18). However, the prevalence of mutations with functional alterations was significantly higher in the obese group (P= 0.022). In conclusions, the results of this large study demonstrate that in the populations studied functionally significant MC3R variants are associated with obesity supporting the current hypothesis that rare variants might have a stronger impact on the individual susceptibility to gain weight. They also underline the importance of detailed in vitro functional studies in order to prove the pathogenic effect of such variants. Further investigations in larger cohorts will be needed in order to define the specific phenotypic characteristics potentially correlated with reduced MC3R signalling.

Investigations of thyroid hormones and antibodies in obesity: leptin levels are associated with thyroid autoimmunity independent of bioanthropometric, hormonal, and weight-related determinants

OBJECTIVES

Obesity can alter the thyroid hormone status as a result of a dysregulated endocrine loop between the hypothalamo-pituitary unit and adipose tissue. The adipocytokine leptin has been shown to promote autoimmunity; hence, we aimed to clarify whether leptin excess of obesity could increase the susceptibility to develop autoimmune thyroid disease (AITD).

STUDY DESIGN

This cross-sectional study was performed in a tertiary care center.

METHODS

Free thyroid hormones, TSH, thyroglobulin, and antithyroid antibodies levels were tested in 165 obese and 118 lean subjects. Results were plotted against variables related to body composition, leptin levels, glucose homeostasis, energy expenditure, and pattern of weight accrual.

RESULTS

Compared with controls, obese patients had lower free T3 levels and free T4 levels (P<0.01), greater prevalence of hypothyroidism (P<0.05), and higher commonness of antithyroid antibodies (P<0.05). As a marker of AITD, thyroid peroxidase antibodies were more frequent in the obese group (P<0.01). Correlation analysis showed that leptin levels were associated with AITD (P<0.01) independent of bioanthropometric variables. Multiple logistic regression analysis in pooled groups identified female sex and leptin as significant predictors of AITD.

CONCLUSIONS

Obesity increases the susceptibility to harbor AITD with an emerging role for leptin as a peripheral determinant, which needs to be confirmed in future investigations.

Obesity-related disability: key factors identified by the International Classification of Functioning, Disability and Health

PURPOSE

To identify obese patients' disability features considering the level of body impairments, activity limitations and participation restrictions in relation to environmental factors' effect.

METHOD

Adult obese inpatients (BMI > 35) were enrolled and were administered a set of 166 ICF categories. Count-based indexes were developed for each ICF component: correlations and regression on performance and capacity indexes were performed.

RESULTS

Fifty-one patients (62.7% females, mean age 38.1) entered in the study. Description of ICF-based disability components is reported. Capacity is better correlated with body functions (r = 0.619, P < 0.01) and body structures (r = 0.375, P < 0.01) than performance; on the contrary, environmental barriers are correlated better with performance (r = 0.531, P < 0.01) than with capacity. Impairments in body functions and environmental barriers are the best predictors of limitations both in capacity and in performance.

CONCLUSIONS

Through this multidisciplinary approach, supported by ICFs biopsychosocial model, we described functioning and disability in obese patients, highlighting the strong effect of body functions' impairments and the limited one of environmental factors. This approach can guide rehabilitation programmes, the promotion of positive health outcomes and the modification of patients' lifestyle, not only intended as an issue of barriers' elimination, but as the activation and maintenance of environmental facilitators.

TECNOB: study design of a randomized controlled trial of a multidisciplinary telecare intervention for obese patients with type-2 diabetes

BACKGROUND

Obesity is one of the most important medical and public health problems of our time: it increases the risk of many health complications such as hypertension, coronary heart disease and type 2 diabetes, needs long-lasting treatment for effective results and involves high public and private costs. Therefore, it is imperative that enduring and low-cost clinical programs for obesity and related co-morbidities are developed and evaluated.

METHODS/DESIGN

TECNOB (TEChnology for OBesity) is a comprehensive two-phase stepped down program enhanced by telemedicine for the long-term treatment of obese people with type 2 diabetes seeking intervention for weight loss. Its core features are the hospital-based intensive treatment (1-month), that consists of diet therapy, physical training and psychological counseling, and the continuity of care at home using new information and communication technologies (ICT) such as internet and mobile phones. The effectiveness of the TECNOB program compared with usual care (hospital-based treatment only) will be evaluated in a randomized controlled trial (RCT) with a 12-month follow-up. The primary outcome is weight in kilograms. Secondary outcome measures are energy expenditure measured using an electronic armband, glycated hemoglobin, binge eating, self-efficacy in eating and weight control, body satisfaction, healthy habit formation, disordered eating-related behaviors and cognitions, psychopathological symptoms and weight-related quality of life. Furthermore, the study will explore what behavioral and psychological variables are predictive of treatment success among those we have considered.

DISCUSSION

The TECNOB study aims to inform the evidence-based knowledge of how telemedicine may enhance the effectiveness of clinical interventions for weight loss and related type-2 diabetes, and which type of obese patients may benefit the most from such interventions. Broadly, the study aims also to have a effect on the theoretical model behind the traditional health care service, in favor of a change towards a new "health care everywhere" approach.

Heart rate behavior during an exercise stress test in obese patients

BACKGROUND AND AIMS

Heart rate (HR) response to exercise has not been fully described in the obese. We wanted to study the differences between obese and non-obese patients in HR behavior during an exercise stress test and to determine whether these differences influence exercise capacity.

METHODS AND RESULTS

We studied 554 patients (318 females) who underwent a treadmill exercise test. All subjects were in sinus rhythm. Patients with ischemic heart disease, with reduced ejection fraction and patients taking drugs that interfere with HR were excluded. The population included 231 patients with BMI<30 kg/m(2) (group 1), 212 patients who were unfit and obese (group 2) and 111 patients who were trained obese (group 3). Resting HR was similar in the various groups. Peak HR, HR recovery and chronotropic index were lower in obese subjects, regardless of their fitness level. Multivariate analysis showed that HR related variables were associated with age, BMI, height, hypertension and various pharmacologic treatments, while exercise capacity was strongly dependent on HR behavior, as well as on sex, age, BMI and diabetes.

CONCLUSION

Obese subjects have a marked impairment of HR behavior during exercise and in the recovery period, and the blunted increase in HR is the most important factor that influences exercise capacity.

Evaluation of rosiglitazone administration on cardiovascular function in severe obesity

BACKGROUND

Obese patients have myocardial structural and functional alterations related to insulin resistance.

HYPOTHESIS

The purpose of the study was to analyze the effects of rosiglitazone, an insulin sensitizer agent, on cardiac morphometry and functioning.

METHODS

In 2 groups of sex- and age-matched, nondiabetic, obese patients (5 men and 7 women, age 19-51 y; group A: body mass index [BMI] 40.6 +/- 3.4 kg/m(2); group B: BMI 42.6 +/- 2.7 kg/m(2)), we evaluated the basal insulin sensitivity index (HOMA[IS]), body composition by bioelectrical impedance analysis and 24-h blood pressure monitoring. Furthermore, all patients underwent conventional 2-Dimensional and color Doppler echocardiography, and pulsed-wave tissue Doppler imaging (TDI). After the baseline evaluation, all patients were put on a hypocaloric diet (70% basal metabolic rate) plus placebo if they were in group A, or plus rosiglitazone (4 mg twice daily; Avandia [GlaxoSmithKline plc., Brentford, Middlesex, United Kingdom]) if they were in group B, for 6 mo.

RESULTS

Significant decreases in body weight, total fat mass, BMI, and systolic blood pressure were registered in both groups. Rosiglitazone administration appeared more efficient in improving HOMA(IS) (mean difference: 0.30 +/- 0.19 versus 0.11 +/- 0.21, p < 0.05). Left ventricular (LV) diastolic diameter (49.4 +/- 7.7 versus 52.3 +/- 5.4 mm, p < 0.05) and E wave (0.89 +/- 0.18 versus 0.99 +/- 0.20 m/sec, p < 0.05) increased in the rosiglitazone group due to a rise in preload and water content without peripheral edema. The increase in systolic (Sa) wave velocity in both groups was probably a result of the general improvement in insulin metabolism and the decrease in blood pressure.

CONCLUSIONS

We confirmed the positive effect of rosiglitazone on glucose metabolism in obese, nondiabetic patients, but changes in insulin sensitivity did not explain the cardiac effects produced by further mechanisms.

Growth hormone therapy improves exercise capacity in adult patients with Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is associated with an inappropriate proportion of fat mass (FM) to non-FM compared to simple obesity. Altered body composition in PWS resembles that seen in subjects with GH deficiency, in which a reduction of lean body mass (LBM) is observed. The low LBM may contribute to the reduced motor skills seen in PWS patients.

AIM

The objective of the study was to investigate the effects of GH therapy on exercise capacity and body composition in a group of adult subjects with PWS.

SUBJECTS AND METHODS

Twelve PWS adults (7 males and 5 females, aged 26.4+/-4.4 yr, body mass index 44.3+/-4.6 kg/m2) participated in the study. Body composition analysis and exercise stress test were carried out throughout the 12 months GH therapy. Body composition was measured by Dual Energy X-ray Absorptiometry. Physical performance was evaluated using treadmill exercise test. Exercise intensity was expressed as metabolic equivalents (MET, 1 MET= 3.5 ml O2 kg(-1) min(-1)). Statistical analysis was performed by repeated-measures analysis of variance followed by post-hoc analysis with t test for paired data for comparisons among the different follow ups.

RESULTS

Compared to baseline GH therapy increased LBM at 6 (p<0.0001) and 12 months (p<0.005) (45.3+/-7.7 kg vs 48.6+/-6.7 kg vs 48.2+/-7.5 kg). FM% was significantly reduced both after 6 and 12 months (p<0.02) (56.1+/-4.8% vs 53.7+/-4.2% vs 53.3+/-4.8%). Attained MET were found to be improved by 16% after 6 months and by 19% after 12 months of GH (p<0.001), while the small further rise between 6 and 12 months was not significant.

CONCLUSIONS

Our findings seem to support the view that GH therapy has beneficial effects on physical activity and agility as well as on body composition of adult patients with PWS.

Subcutaneous abdominal adipose tissue subcompartments: potential role in rosiglitazone effects

Abdominal visceral tissue (VAT) and subcutaneous adipose tissue (SAT), comprised of superficial-SAT (sSAT) and deep-SAT (dSAT), are metabolically distinct. The antidiabetic agents thiazolidinediones (TZDs), in addition to their insulin-sensitizing effects, redistribute SAT suggesting that TZD action involves adipose tissue depot-specific regulation. We investigated the expression of proteins key to adipocyte metabolism on differentiated first passage (P1) preadipocytes treated with rosiglitazone, to establish a role for the diverse depots of abdominal adipose tissue in the insulin-sensitizing effects of TZDs. Adipocytes and preadipocytes were isolated from sSAT, dSAT, and VAT samples obtained from eight normal subjects. Preadipocytes (P1) left untreated (U) or treated with a classic differentiation cocktail (DI) including rosiglitazone (DIR) for 9 days were evaluated for strata-specific differences in differentiation including peroxisome proliferator-activated receptor-gamma (PPAR-gamma) and lipoprotein lipase (LPL) expression, insulin sensitivity via adiponectin and glucose transport-4 (GLUT4), glucocorticoid metabolism with 11 beta-hydroxysteroid dehydrogenase type-1 (11 beta HSD1), and alterations in the adipokine leptin. While depot-specific differences were absent with the classic differentiation cocktail, with rosiglitazone sSAT had the most potent response followed by dSAT, whereas VAT was resistant to differentiation. With rosiglitazone, universal strata effects were observed for PPAR-gamma, LPL, and leptin, with VAT in all cases expressing significantly lower basal expression levels. Clear dSAT-specific changes were observed with decreased intracellular GLUT4. Specific sSAT alterations included decreased 11 beta HSD1 whereas secreted adiponectin was potently upregulated in sSAT with respect to dSAT and VAT. Overall, the subcompartments of SAT, sSAT, and dSAT, appear to participate in the metabolic changes that arise with rosiglitazone administration.

Rosiglitazone is more effective than metformin in improving fasting indexes of glucose metabolism in severely obese, non-diabetic patients

AIM

In obese patients, the diet-induced weight loss markedly improves glucose tolerance with an increase in insulin sensitivity and a partial reduction of insulin secretion. The association with metformin treatment might potentiate the effect of diet alone.

METHODS

From patients admitted to our Nutritional Division for diet programme, we selected obese, non-diabetic, uncomplicated patients with age 18-65 years and body mass index 35-50 kg/m(2) and studied the effects of a 6-month pharmacological treatment with either metformin (850 mg twice daily) or rosiglitazone (4 mg twice daily) on possible changes in body weight, fat mass, glucose and lipids metabolism.

RESULTS

A significant weight loss and reduction of fat mass was demonstrated with metformin (-9.7 +/- 1.8 kg and -6.6 +/- 1.1 kg) and also with rosiglitazone (-11.0 +/- 1.9 kg and -7.2 +/- 1.8 kg), without fluid retention in either treatment group. Rosiglitazone administration induced a significant decrease in glucose concentration (4.7 +/- 0.1 vs. 4.4 +/- 0.1 mmol/l, p < 0.005) and insulin-circulating level (13.6 +/- 1.5 vs. 8.0 +/- 0.,7 microU/ml, p < 0.005), an increase in insulin sensitivity as measured by homeostatic model assessment (HOMA) of insulin sensitivity (68.9 +/- 8.8 vs. 109.9 +/- 10.3, p < 0.005) with a concomitant decrease in beta-cell function as measured by HOMA of beta-cell function (163.2 +/- 16.1 vs. 127.4 +/- 8.4, p < 0.005). In contrast, metformin did not produce any significant effect on blood glucose concentration, insulin level and HOMA2 indexes. No adverse events were registered with pharmacological treatments.

CONCLUSION

Our study shows that in severely obese, non-diabetic, hyperinsulinaemic patients undergoing a nutritional programme, rosiglitazone is more effective than metformin in producing favourable changes in fasting-based indexes of glucose metabolism, with a reduction of both insulin resistance and hyperinsulinaemia. In spite of previous studies reporting rosiglitazone-induced body weight gain, in our study the joint treatment with diet and rosiglitazone was accompanied by weight loss and fat mass reduction.

Short-term effects of a hypocaloric diet and a physical activity programme on weight loss and exercise capacity in obese subjects with chronic ischaemic heart disease: a study in everyday practice

OBJECTIVE

The objective of this paper is to describe the effects of a rehabilitation programme in obese patients affected with chronic ischaemic heart disease; to identify the factors that influence weight loss and improvement in exercise capacity in everyday practice.

METHODS AND RESULTS

We studied 562 white patients (381 men) who followed a 23.3 +/- 3.9 days in-hospital programme. They attended daily sessions of aerobic activity (cycloergometer, walking, and strength exercise); a low-calorie diet was set at approximately 80% of resting energy expenditure. By the end of the programme BMI decreased from 38.0 +/- 4.9 to 36.7 +/- 4.8 kg/m2 (P < 0.001 ). Attained metabolic equivalents (METs) increased from 6.2 +/- 2.5 METs to 7.3 +/- 2.7 (P < 0.001). Age, sex, presence of diabetes and education level were significantly related to the outcomes. Patients who took beta-blockers and statins had less BMI improvement: -1.2 +/- 0.7 kg/m2 vs. -1.4 +/- 0.6 (P = 0.013) and -1.3 +/- 0.6 vs. -1.4 +/- 0.7 (P = 0.023), respectively. Patients that took diuretics and angiotensin receptor blockers (ARB) had less improvement in exercise capacity: 0.9 +/- 1.0 METS vs. 1.3 +/- 1.3 (P < 0.001) and 0.8 +/- 1.3 vs. 1.2 +/- 1.3 (P = 0.011 ), respectively. After a median interval of 358 days, 152 patients were seen at a follow-up visit: their BMI increased by 1.0 +/- 2.4 kg/m2 and only 21% of patients lost weight.

CONCLUSIONS

Rehabilitation improves exercise capacity and induces significant weight loss in obese patients with stable IHD, but women, diabetic, elderly and poorly educated subjects obtained unsatisfactory results. Use of diuretics and ARB seem to worsen the results. At follow-up only a small percentage of patients further improves BMI.

Deep subcutaneous adipose tissue: a distinct abdominal adipose depot

OBJECTIVE

Abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) display significant metabolic differences, with VAT showing a functional association to metabolic/cardiovascular disorders. A third abdominal adipose layer, derived by the division of SAT and identified as deep subcutaneous adipose tissue (dSAT), may play a significant and independent metabolic role. The aim of this study was to evaluate depot-specific differences in the expression of proteins key to adipocyte metabolism in a lean population to establish a potential physiologic role for dSAT.

RESEARCH METHODS AND PROCEDURES

Adipocytes and preadipocytes were isolated from whole biopsies taken from superficial SAT (sSAT), dSAT, and VAT samples obtained from 10 healthy normal weight patients (7 women and 3 men), with a mean age of 56.4 +/- 4.04 years and a mean BMI of 23.1 +/- 0.5 kg/m2. Samples were evaluated for depot-specific differences in insulin sensitivity using adiponectin, glucose transport protein 4 (GLUT4), and resistin mRNA and protein expression, glucocorticoid metabolism by 11beta-hydroxysteroid dehydrogenase type-1 (11beta-HSD1) expression, and alterations in the adipokines leptin and tumor necrosis factor-alpha (TNF-alpha).

RESULTS

Although no regional differences in expression were observed for adiponectin or TNF-alpha, dSAT whole biopsies and adipocytes, while intermediary to both sSAT and VAT, reflected more of the VAT expression profile of 11beta-HSD1, leptin, and resistin. Only in the case of the intracellular pool of GLUT4 proteins in whole biopsies was an independent pattern of expression observed for dSAT. In an evaluation of the homeostatic model, dSAT 11beta-HSD1 protein (r = 0.9573, p = 0.0002) and TNF-alpha mRNA (r = 0.8210, p = 0.0236) correlated positively to the homeostatic model.

DISCUSSION

Overall, dSAT seems to be a distinct abdominal adipose depot supporting an independent metabolic function that may have a potential role in the development of obesity-associated complications.

Conditional cardiovascular response to growth hormone therapy in adult patients with Prader-Willi syndrome

CONTEXT

In Prader-Willi syndrome (PWS), an altered GH secretion has been related to reduced cardiac mass and systolic function when compared with controls.

OBJECTIVES

The objective of the study was to evaluate the cardiovascular response to GH therapy in adult PWS patients.

STUDY PARTICIPANTS

Thirteen obese PWS adults (seven males and six females, aged 26.9+/-1.2 yr, body mass index 46.3+/-1.6 kg/m2) participated in the study.

METHODS

Determination of IGF-I, metabolic parameters, echocardiography, and cardioscintigraphy with dobutamine stimulation was made during 12 months GH therapy, with results analyzed by repeated-measures ANOVA.

RESULTS

GH therapy increased IGF-I (P<0.0001); decreased C-reactive protein levels (P<0.05); and improved lean mass (P<0.001), fat mass (P<0.05), and visceral fat (P<0.001). Echocardiography showed that 6- and 12-month GH therapy increased left ventricle mass in 76 and in 61% of patients, respectively (P<0.05), did not change diastolic function, and slightly decreased the left ventricle ejection fraction (LVEF) (P=0.054). Cardioscintigraphy documented stable values of LVEF throughout the study, whereas right ventricle ejection fraction decreased significantly (P<0.05) being normally responsive to dobutamine infusion. A positive association between IGF-I z-scores and LVEF occurred at the 6- and 12-month follow-up (P<0.05).

CONCLUSIONS

In PWS, GH therapy increased cardiac mass devoid of diastolic consequences. The observation of a slight deterioration of right heart function as well as the association between IGF-I and left ventricular function during GH therapy suggest the need for appropriate cardiac and hormonal monitoring in the therapeutic strategy for Prader-Willi syndrome.

Evaluation of a multisensor armband in estimating energy expenditure in obese individuals

OBJECTIVE

To examine the reliability and validity of the SenseWear Pro 2 Armband (SWA; Body Media, Pittsburgh, PA) during rest and exercise compared with indirect calorimetry (IC) in obese individuals.

RESEARCH METHODS AND PROCEDURES

Energy expenditure was assessed during rest with the SWA and IC in 142 obese adults (37 men and 105 women, BMI = 42.3 +/- 7.0) and in 25 lean and overweight adults (BMI = 25.3 +/- 3.2) who were used as a comparison group. Twenty-nine of the obese adults also participated in three separate short exercise sessions including cycle ergometry, stair stepping, and treadmill walking.

RESULTS

The repeatability of SWA estimates in obese subjects was high (r = 0.88, p < 0.001). The SWA generally underestimated the resting energy expenditure (REE) (1811 +/- 346 vs. 1880 +/- 382 kcal/d) and highly overestimated the energy expenditure during the exercise sessions in obese individuals. REE estimations by SWA were significantly correlated with fat-free mass (r = 0.88, p < 0.001). Bland-Altman plots based statistical analysis for the estimated REE, and measured IC showed a low agreement (Total Error > 20% but Systematic Error < 5%) between the two methods in obese subjects, although they showed a high correlation and a very good agreement in lean and overweight patients.

DISCUSSION

The SWA is an easy to handle, practical, new portable device for measuring energy expenditure. The accuracy of the SWA appeared to be poor in the obese subjects we examined, especially those with high REE both in rest and exercise. We believe that it is necessary to incorporate new, obesity-specific algorithms in the relative software.

Predictors of postabsorptive ghrelin secretion after intake of different macronutrients

CONTEXT

Release of ghrelin, a gastrointestinal hormone regulating feeding and energy balance, is blunted in obesity, a condition associated with insulin resistance.

OBJECTIVE

The objective was to identify anthropometric and metabolic predictors of postabsorptive ghrelin secretion.

DESIGN

We evaluated ghrelin, insulin, glucose, and leptin secretion overnight and after intake of different macronutrients.

SUBJECTS

Ten obese subjects (age, 31.8 +/- 2.5 yr; body mass index, 43.4 +/- 0.8 kg/m(2)) and six lean subjects (age, 33.5 +/- 2.4 yr; body mass index, 21.8 +/- 1.4 kg/m(2)) participated in the study.

MAIN OUTCOME MEASURES

The main outcome measures were resting energy expenditure (REE); fat mass; nighttime approximate entropy (ApEn) and synchronicity (cross-ApEn) of ghrelin, insulin, and leptin; insulin sensitivity by homeostatic model approach insulin-sensitivity (HOMA-S%); postabsorptive area under the curve (AUC); and Delta of ghrelin, insulin, glucose, and leptin after carbohydrate-, lipid-, and protein-rich test meals.

RESULTS

Nighttime ApEn scores were higher in obese than lean subjects (P < 0.01). Cross-ApEn revealed a synchronicity between ghrelin-insulin, ghrelin-leptin, and insulin-leptin in both groups. Compared with baseline, ghrelin decreased significantly (P < 0.01) in lean and obese subjects after carbohydrates (42.2 vs. 28.5%; P < 0.05), lipids (40.2 vs. 26.2%; P < 0.01), and proteins (42.2 vs. 26.3%; P < 0.01) devoid of between-meal ghrelin differences. Significant associations occurred between nocturnal ghrelin ApEn and insulin (r = 0.53; P < 0.05), postmeal ghrelin AUCs and REE (r = -0.57; P < 0.05), and HOMA-S% (r = 0.52; P < 0.05), postmeal ghrelin Delta and HOMA-S% (r = 0.60; P < 0.05). REE (beta = -0.57; P = 0.02) and ghrelin ApEn (beta = -0.62; P = 0.01) were predictors of postmeal ghrelin AUC and Delta, respectively.

CONCLUSIONS

Obesity determined a decreased orderliness of ghrelin secretion and a relative loss of ghrelin-insulin synchrony. Postabsorptive ghrelin secretion decreased significantly both in obese and lean subjects, was related to insulin sensitivity, and was predicted by energy expenditure and hormone pulsatility.

Impairment of GH responsiveness to combined GH-releasing hormone and arginine administration in adult patients with Prader-Willi syndrome

OBJECTIVE

It is unclear if poor health outcomes of adult patients with Prader-Willi syndrome (PWS) are influenced by GH deficiency (GHD). Few studies have been focused on PWS adults, but further information on the concomitant role of obesity on GH/IGF-I axis function is needed. The aim of our study was to investigate the prevalence of GHD in a large group of adult subjects with genetically confirmed PWS.

DESIGN AND SUBJECTS

We studied the GH response to a combined administration of GHRH (1 microg/kg i.v. at 0 minutes) and arginine (ARG) (30 g i.v., infused from 0 to 30 minutes) as well as the baseline IGF-I levels, in a group of 44 PWS adults (18 males, 26 females) aged 18-41.1 years. The same protocol was carried out in a control group of 17 obese subjects (7 males, 10 females) aged 21.8-45.8 years.

MEASUREMENTS

Blood samples were taken at -15 and 0 minutes and then 30, 45, 60, 90 and 120 minutes after GHRH administration. Serum GH and total IGF-I concentrations were measured by chemioluminescence. Statistical analysis was performed by Student's t-test for unpaired data, and using analysis of variance for parametric and nonparametric (Mann-Whitney test) data, where appropriate. The relationship between pairs of variables was assessed by Pearson's correlation. Independent variables influencing GH secretion were tested by multiple linear regression analysis.

RESULTS

The GH response to GHRH + ARG was significantly lower in PWS patients (GH peak (mean +/- SE) 8.4 +/- 1.2 microg/l; AUC: 471.4 +/- 77.8 microg/l/h) than obese subjects (GH peak 15.7 +/- 2.9 microg/l, P < 0.02; AUC 956 +/- 182.9 microg/l/h, P < 0.005). When considered individually, 17 of 44 PWS individuals (38.6%) were severely GHD, according to the cut-off limit of 4.1 microg/l for obese individuals, and low IGF-I-values were present in 33 PWS patients. Moreover, impaired GH response was combined with subnormal IGF-I levels in all PWS patients with GHD.

CONCLUSIONS

Adult subjects with PWS had a reduced responsiveness to GHRH + ARG administration associated with reduced IGF-I levels. In addition, a severe GHD for age was demonstrated in a significant percentage of PWS subjects. These findings are in agreement with the hypothesis that a complex derangement of hypothalamus-pituitary axis occurred in PWS, and suggested that impaired GH secretion is not an artefact of obesity.

Lack of association between the tetranucleotide repeat polymorphism in the 3'-flanking region of the leptin gene and hypertension in severely obese patients

Conflicting data suggest an association between leptin gene polymorphisms and essential hypertension independently of obesity. The aim of this study was to evaluate, in severely obese subjects, the role of one of these polymorphic markers in relation to the development of hypertension. The study included 325 obese patients with mean body mass index (BMI) of 46+/-6.94 kg/m2. One hundred sixty-six were hypertensive and 159 normotensive. In both groups, the presence of a tetranucleotide repeat in the 3' flanking region of the Ob gene was investigated using polymerase chain reaction (PCR). Due to the genetic variant, in the region studied it is possible to distinguish two alleles with different size distribution: Class I (shorter one) and Class II (longer one). Class I and Class II allele frequencies were not significantly different in obese patients when analyzed according to the presence or absence of hypertension. The results presented herein do not support a significant association of this Ob gene polymorphism with hypertension. These findings are in contrast with that reported in other populations. However, we cannot rule out that different ethnicity and/or phenotypic variability might mask small effects.

A simple tool to predict exercise capacity of obese patients with ischaemic heart disease

OBJECTIVE

To define an equation that predicts exercise capacity taking into account body mass index (BMI).

DESIGN

Retrospective analysis and validation study of a multidisciplinary programme aimed at weight loss and physical rehabilitation.

SETTING

Tertiary referral hospital.

PATIENTS AND METHODS

372 consecutive obese participants (249 men) with stable ischaemic heart disease, aged mean 60.1 (SD 8.7) years, underwent a treadmill exercise test. BMI was 37.8 (4.5) kg/m(2). In the validation study the model was tested in 87 patients with similar characteristics.

RESULTS

Mean exercise intensity was 6.6 (SD 2.4) metabolic equivalents (METs). Multivariate linear regression analysis defined two simple models that considered exercise intensity as the dependent variable and a set of independent variables such as anthropometric measures, age and sex in the first one, plus associated clinical conditions and drug treatment in the second one. The correlation coefficients of the two models were R = 0.630 and R = 0.677, respectively. Age, BMI and sex were the strongest predictors of exercise capacity. The first derived equation efficiently predicted exercise capacity: in the validation study predicted exercise intensity was 6.3 (1.6) METs and attained exercise intensity was 6.3 (2.4) METs (p = 0.903) with a highly significant correlation (R = 0.534, p < 0.001).

CONCLUSION

BMI is an important determinant of exercise capacity of obese people with ischaemic heart disease. The use of a simple equation may help in predicting exercise capacity, in individualising exercise protocol and in setting up rehabilitation programs for obese patients.

Abdominal fat index by ultrasound does not estimate the metabolic risk factors of cardiovascular disease better than waist circumference in severe obesity

OBJECTIVE

To evaluate by ultrasound the ratio between preperitoneal (P) and subcutaneous (S) fat (AFI), in quantifying the cardiovascular risk in 258 obese patients (BMI 41.2+/-6.3 kg/m2; age 45.1 +/- 13.6 years).

RESEARCH METHODS AND PROCEDURES

Glucose, insulin, lipid profile, uric acid and fibrinogen were measured. HOMA-IR, waist girth, AFI and quartiles of BMI were calculated.

RESULTS

AFI lowered with increasing BMI and showed a positive correlation with TGL (r=0.37, P<0.01) and uric acid (r=0.40, P<0.001) in the 1st quartile of BMI (30.2-36.4) and a negative correlation with HDL (r=- 0.32, P<0.001) in the 3rd quartile (40.6-45.1). When BMI exceeded the value of 45.2 kg/m2 these correlations were no longer significant. In all subjects S correlated positively with uric acid (r=0.64, P<0.001), and negatively with HOMA-IR (r=- 0.41, P<0.001) and TGL (r=- 0.35, P=0.02); P correlated positively with CHOL (r=0.48, P=0.04) and TGL (r=0.33, P=0.03), and negatively with HDL (r=- 0.46, P=0.03). Waist girth showed more significant correlations than AFI in the lower quartiles of BMI, but not at the highest one.

DISCUSSION

AFI, P and S, as waist girth do not seem to quantify the metabolic risk factors of cardiovascular disease in severe obese subjects, but AFI is probably useful in obese populations with BMI<45 kg/m2, even though not as strong as waist girth.

The impact of growth hormone/insulin-like growth factor-I axis and nocturnal breathing disorders on cardiovascular features of adult patients with Prader-Willi syndrome

CONTEXT

Adult patients with Prader-Willi syndrome (PWS) are prone to develop obesity, GH deficiency (GHD), and their related complications, with cardiopulmonary failure explaining more than half of PWS fatalities. OBJECTIVE AND STUDY PARTICIPANTS: This study was undertaken to examine the effect of GHD and sleep breathing disorders on cardiovascular risk factors and heart features of 13 PWS (age 26.9 +/- 1.2 yr) and 13 age-, gender-, and body mass index-matched obese individuals (age 26.2 +/- 0.8 yr).

RESULTS

Compared with controls, PWS patients had lower GH response to arginine+GHRH, IGF-I levels, triglycerides, total and LDL-cholesterol, insulin, and insulin resistance measured by a homeostatic model approach. Dual-energy x-ray absorptiometry, abdominal computed tomography scans, and polysomnography revealed a greater fat mass, similar abdominal fat, but greater sleep breathing disorders in PWS than obese subjects. Echocardiography showed no systolic or diastolic alteration, although PWS had lower left ventricle (LV) mass (135.7 +/- 7.7 vs. 163.5 +/- 8.4 g, P < 0.05) and near significantly lower values of LV end-diastole diameter (P = 0.08), compared with obese controls. Baseline radionuclide angiography documented comparable values of systolic and diastolic values between groups. However, adrenergic stimulation with dobutamine caused a lower increase of LV ejection fraction (71.9 +/- 1.9 vs. 76.3 +/- 1.2%, P < 0.05) and heart rate (103 +/- 6.9 vs. 128 +/- 2.8 beats/min, P < 0.05) in PWS than obese individuals. By multivariate analysis, nocturnal oxygen desaturation and IGF-I levels were main significant predictors of LV mass and heart rate in PWS patients.

CONCLUSIONS

PWS differs from simple obesity by a healthier metabolic profile, impaired nocturnal breathing, decreased heart geometry, and systolic and chronotropic performance. GHD and the predictive role of IGF-I on structural and functional heart parameters suggest a GH/IGF-I-mediated control of cardiac risk in PWS.

Safety and efficacy of therapy with botulinum toxin in obesity: a pilot study

BACKGROUND

Botulin toxin (BTX) has been proposed as a potential obesity treatment.

METHODS

In a pilot study, the short-term efficacy and safety of BTX was assessed in eight subjects (four men, four women; median age, 46 years; range, 35-57 years) with severe obesity (median body mass index [BMI], 47.1 kg/m(2); range 38.2-56.7 kg/m(2)) and multiple dietary treatment failures. In a single endoscopic session, 500 UI of BTX-A was injected in the gastric antral region.

RESULTS

No clinically significant side effects were observed. In all patients, despite their not being on a specific diet, a reduction of body weight was observed at 1 month (median baseline weight, 124.4 kg vs 121.8 kg at 1 month; P < 0.05). Two treatment-unrelated dropouts were observed. At 4 months, three of the six patients had a further weight loss. The treatment effect was apparently independent of changes in hunger or satiety, or of changes in fasting and postprandial plasma ghrelin and serum leptin, thus suggesting a different pharmacological mechanism.

CONCLUSIONS

BTX-A treatment appears to be safe and well tolerated by obese patients, while its short-term efficacy varied widely.

Paraoxonase activity in high-density lipoproteins: a comparison between healthy and obese females

Paraoxonase, an enzyme associated with high-density lipoprotein (HDL-PON), exerts a protective effect against oxidative damage of circulating cells and lipoproteins, modulates the susceptibility of HDL to atherogenic modifications such as glycation and homocysteinylation, and even exerts an antiinflammatory role. The aim of the present study was to investigate the relationship between lipoprotein oxidative stress and the activity of HDL-PON in healthy and obese subjects. Therefore, the activity of HDL-PON and the levels of lipid hydroperoxides in HDL and low-density lipoprotein (LDL) isolated from plasma of obese females (n = 12) and age-sex-matched controls (n = 31) were compared. Our results demonstrated for the first time that the activity of HDL-PON in obese subjects was significantly lower compared with that in controls (P < 0.001). Moreover, our results showed a significant increase in the levels of lipid hydroperoxides in HDL and LDL isolated from obese subjects (P < 0.001). The negative correlations established between HDL-PON activity and the levels of lipid hydroperoxides associated with HDL and LDL confirm the relationship between paraoxonase activity and lipid peroxidation of lipoproteins. Plasma levels of leptin correlated negatively with HDL-PON activity and positively with levels of lipid hydroperoxides in HDL and LDL of obese subjects, suggesting a relationship between leptin and oxidative damage of lipoproteins. In conclusion, our study demonstrated that the increase in oxidative stress in LDL and HDL of obese subjects is associated with a decrease in HDL-PON activity. The lower paraoxonase activity and the compositional changes in HDL and LDL could contribute to the greater risk of cardiovascular disease associated with obesity.

Free and bound plasma leptin in normal weight and obese men and women: relationship with body composition, resting energy expenditure, insulin-sensitivity, lipid profile and macronutrient preference

OBJECTIVE

The adipose-borne hormone leptin circulates in free and protein-bound forms but little information is available about their biological significance. Free leptin (FL) levels are related to changes in fat mass, whereas bound leptin (BL) appears to be associated with resting energy expenditure (REE). Our aim was to assess FL and BL levels in normal weight and obese subjects and correlate them with metabolic and nutritional variables.

DESIGN AND PATIENTS

The partitioning of plasma leptin between FL and BL was evaluated in a population (n = 44) including both genders and different degrees of adiposity [body mass index (BMI) range 18.6-79.6 kg/m2].

MEASUREMENTS

Total leptin and FL and BL concentrations were measured by fast protein liquid chromatography (FPLC) followed by radioimmunoassay (RIA). Body composition, REE, insulin sensitivity, lipid parameters associated with cardiovascular risk and macronutrient preference were also assessed.

RESULTS

The BL/FL ratio was significantly reduced in obese subjects due to a major increase in FL compared with BL. Consequently, the gender difference of the %BL/%FL ratio present in lean subjects (35/65 in women; 65/35 in men) was lost in obese subjects. REE was negatively correlated with total leptin (P < 0.0001) and %FL (P < 0.0001), and positively with %BL (P < 0.001). Total leptin and FL were correlated with the diet carbohydrate content in all subjects.

CONCLUSIONS

FL increases with the amount of fat mass; the prevalence of FL in normal weight women in comparison to men suggests that this fraction is particularly linked to the amount of subcutaneous fat. Moreover, the correlation of BL with REE and the relationship of FL with food intake favours the view of different biological activities for the two circulating forms of leptin.

Weight cycling and cardiovascular risk factors in obesity

OBJECTIVE

To assess the relationship between weight cycling and some cardiovascular risk factors in a wide sample of obese subjects.

DESIGN

Cross-sectional study with retrospective evaluation of weight and dieting history.

SUBJECTS

In all, 459 obese subjects, 340 women and 119 men (age: 19-65 y; BMI: 30-69 kg/m2).

MEASUREMENTS

Body composition and fat distribution (by bioelectrical impedance analysis and anthropometry), systolic and diastolic blood pressure, plasma glucose, total and HDL cholesterol, triglycerides, insulin and insulin resistance by HOMAir, various weight cycling indices.

RESULTS

A positive correlation between weight cycling indices, BMI and percent body fat was found in both genders. Also, the maximum absolute amount of weight regained following a single diet episode was significantly associated to insulin and HOMAir in both genders. However, these correlations disappeared when the data were controlled for age and BMI.

CONCLUSION

In obese subjects of both genders weight cycling, and in particular weight regain, does not appear to be associated with adverse effects on body composition, fat distribution or cardiovascular risk factors in an independent manner, but rather in relation to fat accumulation over years.

The relationship between active ghrelin levels and human obesity involves alterations in resting energy expenditure

Ghrelin is a gastric hormone that exerts a stimulatory effect on appetite and fat accumulation. Ser(3) octanoylation is regarded as a prerequisite for ghrelin biological activity, although des-octanoylated forms may retain biological functions in vitro. Circulating ghrelin levels are usually low in obesity and in states of positive energy balance. Hence, the aim of our study was to analyze plasma active and serum total ghrelin levels in 20 obese (ages, 22-42 yr; body mass index, 41.3 +/- 1.1 kg/m(2)) and 20 lean subjects (ages, 22-43 yr; body mass index, 22.4 +/- 0.6 kg/m(2)) as well as their relationship to measures of glucose homeostasis, body fat, and resting energy expenditure (REE). The measured/predicted REE percentage ratio was calculated to subdivide groups into those with positive (> or = 100% ) and negative (<100%) ratio values. In obese patients, plasma active (180 +/- 18 vs. 411 +/- 57 pg/ml; P < 0.001) and serum total ghrelin levels (3650 +/- 408 vs. 5263 +/- 643 pg/ml; P < 0.05) were significantly lower when compared with lean subjects. Hence, ghrelin activity, defined as the proportion of active over total ghrelin levels, was similarly reduced in the obese state (6.1 +/- 0.9% vs. 8.4 +/- 1%; P < 0.05). There was a significant correlation between active and total ghrelin (r = 0.62; P < 0.001), and between total ghrelin and insulin (r = -0.53; P < 0.001) or insulin resistance using the homeostatis model of assessment-insulin resistance (r = -0.49; P < 0.001) approach. Significantly higher active ghrelin levels (214 +/- 22 vs. 159 +/- 30 pg/ml; P < 0.05) and ghrelin activity (8 +/- 1.7% vs. 4.9 +/- 0.9%; P < 0.05) were observed in patients with positive compared with negative measured/predicted REE ratio values. Our study shows that obesity is associated with an impairment of the entire ghrelin system. The observation that ghrelin is further decreased in cases of abnormal energy profit adds new evidence to the relationship between ghrelin activity and energy balance in obesity.

Lack of association between UCP2 gene polymorphisms and obesity phenotype in Italian Caucasians

The importance of the genetic component on adipose tissue accumulation has been clearly demonstrated. Among the candidate genes investigated, there are those that regulate thermogenesis and, thus, can affect energy expenditure. The uncoupling proteins (UCPs) are a family of proteins that uncouple respiration leading to generation of heat and increased energy expenditure. Contradictory data indicate that allelic variants in their coding genes might be associated with obesity. In this study we evaluated the role of two allelic variants of the UCP2 gene in obesity and the association with its sub-phenotypic characteristics. To this aim, 360 morbidly obese patients [age: 45 +/- 15 yr, body mass index (BMI): 46 +/- 7 kg/m2] and 103 normal weight subjects (BMI < 24 kg/m2) were genotyped for the 45 bais-pair (bp) insertion/deletion (I/D) in the 3'-untraslated region of exon 8 of the UCP2 gene while the presence of an Ala/Val substitution at codon 55 (Ala55Val) of the same gene was studied in 104 obese and 50 lean subjects. Patients also underwent a study protocol including measurements of BMI, waist-to-hip ratio (WHR), resting energy expenditure (REE), energy intake, fat mass (FM) and free fat mass (FFM), total cholesterol (TCH), high density lipoprotein (HDL) cholesterol, triacylglyceroles (TG), leptin levels, basal glucose, immunoreactive insulin (IRI), glycated haemoglobin (HbA1c), insulin sensitivity and thyroid hormones. No significant association between the two polymorphisms studied and the clinical, metabolic and anthropometric parameters characteristic of the obese phenotype was found. These results, in accordance with similar findings previously obtained in other ethnic groups, suggest that these two UCP2 allelic variants may not have a direct role in the pathogenesis and development of obesity.

Feasibility of air plethysmography (BOD POD) in morbid obesity: a pilot study

The assessment of body composition (BC) in morbidly obese patients is a difficult procedure. Air-displacement plethysmography (ADP), which measures body density, is a very promising technique for BC assessment in health and disease. However, there are very few data about the feasibility of applying ADP on morbidly obese patients, which theoretically could be affected by large body size and difficulty in lung volume measurements. The main aim of this pilot study was to evaluate the feasibility of using ADP for BC assessment in morbidly obese patients. We studied nine subjects (6 males and 3 females) who had a mean age (+/-SD) of 47.0+/-13.5 years and body mass index (BMI) of 46.6+/-7.7 kg/m(2) (range 36.4-58.8). All patients could fit into the instrument chamber and perform the manoeuvre for pulmonary plethysmography. Mean lung volume was 3.9+/-1.2 l and mean percent body fat was 53.1+/-6.6 (range 46.0-67.5). These results indicate that ADP appears to be suitable for patients with BMI over 40 kg/m(2) and produces realistic BC data.

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.

Effect of chronic treatment with beta-blockers on resting energy expenditure in obese hypertensive patients during a low-calorie and physical training program

BACKGROUND AND AIM

To evaluate whether chronic treatment with beta-blockers influences resting energy expenditure (REE) and weight loss after a period of diet and physical activity in obese hypertensive patients.

METHODS AND RESULTS

Seventy-eight obese hypertensive patients (24 males and 54 females) aged 53.7 +/- 11.1 years with mean BMI of 42.4 +/- 5.8 kg/m2 were enrolled. Thirty-eight patients were using beta-blockers while 40 patients who had not received beta-blockers in the past 6 months were the control group. REE was measured with indirect calorimetric method. Total body fat mass, total body fat-free mass (FFM) and total body water (W) were determined by bioelectrical impedance analysis. Patients and controls underwent a structured physical training program and a hypocaloric diet for a period of 31.6 +/- 10.6 days. Measured REE in patients taking beta-blockers was 1818 +/- 309 kcal/24 h and 1853 +/- 348 kcal/24 h in patients not taking beta-blockers; p = non significant. Weight and BMI loss were similar between the two groups and were respectively -6.43 +/- 2.62 kg and -2.42 +/- 0.91 kg/m2 in the beta-blocker group and -7.49 +/- 3.10 kg, -2.78 +/- 1.03 kg/m2 in the non beta-blocker group. Body composition was similar in the two groups. In the comparison between patients treated with selective beta 1-adrenoceptors blockers and non selective beta-blockers we found a significant difference in REE (1704 +/- 283 vs 1974 +/- 278; p = 0.012) and in weight loss (-5.6 +/- 2.4 vs -7.5 +/- 2.7; p = 0.048) at the end of study.

CONCLUSIONS

Beta-blockers are not associated with a lower REE in obese subjects compared to other antihypertensive treatment. Use of non selective beta-adrenergic blockers is associated with a higher REE and weight loss compared to use of selective beta 1-adrenergic blockers. Non selective beta-blockers could be indicated among first choice drugs in hypertensive severely obese subjects without contraindications to beta-blockade.

The relation between two polymorphisms in the glucocorticoid receptor gene and body mass index, blood pressure and cholesterol in obese patients

OBJECTIVE

We have recently reported that, in healthy elderly Dutch individuals, a N363S polymorphism in the glucocorticoid receptor (GR) gene is associated with higher sensitivity to low-dose dexamethasone (0.25 mg), evaluated as both cortisol suppression and insulin response, and with an increased body mass index (BMI). In the present study we investigated the role of the N363S polymorphism, and a BclI restriction site polymorphism in a group of Italian patients with severe obesity.

DESIGN

Two hundred and seventy-nine patients (mean BMI 45.9 +/- 0.9 kg/m2) were genotyped using both PCR-restriction fragment length polymorphism analysis and Taqman Sequence Detection System. Determination of several metabolic and antropometric parameters was also performed in order to correlate them to the genotype.

RESULTS

In this group of obese patients, 13 subjects (eight female, five males) were heterozygous for the N363S variant (allelic frequency 2.3%) and had significantly higher BMI (P < 0.04), resting energy expenditure (P < 0.03) and food intake (P < 0.01) when compared to wild-type homozygotes. When the data were analysed according to sex, female heterozygotes for the N363S allele had significantly higher BMI (P = 0.04), resting energy expenditure (P = 0.03) and food intake (P = 0.008) than obese women with the wild-type 363 GR gene. Male carriers of this variant also had higher values for these variables although the differences did not reach statistical significance. A case-control study with homozygous wild-type obese subjects which were age-, sex- and BMI-matched, revealed no difference in resting energy expenditure and food intake. The allele frequency of the BclI variant was 27% (89 females and 41 males out of 269 subjects). No differences in anthropometric and metabolic parameters were found between subjects heterozygous or homozygous for this variant GR in this obese population. However, when we studied the effect of the presence of the BclI polymorphism and the N363S variant in the same individual, we found that the subjects who carried both polymorphisms had a tendency towards higher systolic and diastolic blood pressure and significantly higher total and LDL-cholesterol levels (P = 0.005 and P = 0.05, respectively).

DISCUSSION

Taking the results of this study and those obtained in the Dutch population, we speculate that heterozygous carriers of the N363S variant who develop obesity, may become even more obese, possibly because they have a hypersensitive insulin response and thus, via activation of lipogenesis, store fat more efficiently. Furthermore, these data suggest that N363S carriers who carry the BclI polymorphism as well, tend to have a slightly unfavourable cardiovascular profile.

Bone mineral density in acromegaly: the effect of gender, disease activity and gonadal status

OBJECTIVE

Data on bone mineral density (BMD) in acromegaly are conflicting as most previous studies collectively evaluated eugonadal and hypogonadal patients of both sexes, with or without active disease. We have evaluated BMD in 152 acromegalic patients of both sexes with varying disease activity and gonadal status.

DESIGN

Cross-sectional, retrospective.

PATIENTS

We studied 152 acromegalic patients (99 women aged 26-72 years, and 53 men aged 21-75 years), 107 with active and 45 with controlled disease. Eighty-five patients had normal gonadal status and 67 were hypogonadal.

MEASUREMENTS

In all patients we measured serum GH levels by immunoenzimometric assay, and serum IGF-I levels by radioimmunoassay. BMD was assessed at spine L2-L4 (LS) and at femoral neck (FN) by dual energy X-ray absorptiometry; results are expressed as Z-values.

RESULTS

We evaluated the effect of GH excess on bone at different sites in relation to gonadal status, disease activity and gender. At LS, in respect to the reference population, BMD (mean +/- SE) values were higher in eugonadal patients (active: 0.71 +/- 0.29, P < 0.02; controlled: 0.65 +/- 0.28, P < 0.05) and lower in hypogonadal ones (active: -0.64 +/- 0.35, 0.1 < P < 0.05; controlled: -1.05 +/- 0.36, P < 0.01), regardless of disease activity. On the contrary, at FN, BMD was higher than in the reference population, both in eugonadal (1.01 +/- 0.22, P < 0.001) and hypogonadal (0.63 +/- 0.17, P < 0.001) patients only in subjects with active disease, but not in those in which the disease was controlled (eugonadal: 0.31 +/- 0.23, P = ns; hypogonadal 0.04 +/- 0.28, P = ns). We did not observe any difference in BMD values according to gender both at LS (males vs. females -0.02 +/- 0.30 vs. 0.01 +/- 0.24, P = ns) or at FN (0.77 +/- 0.19 vs. 0.63 +/- 0.15, P = ns).

CONCLUSIONS

The anabolic effect of GH excess on bone in acromegalic patients is: (i) gender-independent; (ii) evident at the spine only in eugonadal regardless of disease activity; (iii) evident at femoral neck only in the presence of active disease regardless of gonadal status.

PRL-secreting pituitary adenomas in pregnancy

Dopamine-agonists have significantly increased the number of pregnancies in women with micro- and macro-prolactinomas, as ovulation can be restored in the great majority of these patients. Thus, the main questions regard the possible consequences of high estrogen levels on tumor volume and the possible effects of D2-agonists on fetal development. While the risk of tumor increase is low in patients with prolactin secreting micro-adenoma (MIP), in PRL secreting macro-adenoma (MAP) patients the possibility of tumor growth is enhanced and influenced by previous treatment. Moreover, while it is well known that the exposition for only the first 4 weeks to bromocriptine (BRC) therapy does not affect the outcome of pregnancy, data on the use of BRC during the whole gestation are limited to just over 100 cases. Female pregnant patients with MIP, therefore, must be reassured and medical therapy suspended, with successive clinical follow-up. In the case of pregnant MAP subjects, the best approach from pre-pregnancy debulking, dopamine-agonist therapy interruption and BRC therapy continuation must be agreed on with the patient, and a careful follow-up instituted.

Prevalence of thyroid diseases in patients with acromegaly: results of an Italian multi-center study

Acromegaly is frequently associated with the presence of thyroid disorders, however the exact prevalence is still controversial. An Italian multicenter study was performed on 258 patients with active acromegaly (high levels of IGF-I and lack of suppression of serum GH levels below 2 microg/l after an OGTT). The control group was represented by 150 patients affected by non-functioning and PRL-secreting pituitary adenomas. Two hundred and two out of 258 acromegalic patients (78%) were affected by thyroid disorders with a significantly higher prevalence with respect to the control group (27%, p<0.0001). One hundred and three patients presented (39.9%) non-toxic nodular goiter, 46 (17.8%) non-toxic diffuse goiter, 37 (14.3%) toxic nodular goiter, 1 toxic diffuse goiter (0.4%), 12 (4.6%) Hashimoto's thyroiditis, 3 (1.2%) thyroid cancer. Two patients presented a co-secreting TSH pituitary adenoma. Thirty-six patients had been previously treated for various thyroid abnormalities. Among the 222 acromegalic patients never treated for thyroid disorders thyroid ultrasonography was performed on 194 subjects. Thyroid volume in patients with thyroid abnormalities was 28+/-17.5 ml (median 23) while it was 10.8+/-3.6 ml (median 10) in patients without thyroid disorders (p<0.0001). Thyroid volume was correlated with the estimated duration of acromegaly (r=0.7, p<000.1), but not with age or with serum GH, IGF-I and TSH concentrations. Thyroid volume was higher in acromegalic patients than in the above control population (23.5+/-16.9 ml vs 13.9+/-12.8 ml, p<0.0001). In 62 acromegalic patients 101 fine-needle biopsies of thyroid nodules were performed; 7 nodules were suspicious and the patients were submitted to thyroid surgery: papillary thyroid carcinoma was found in 3 patients. In conclusion, in a large series of acromegalic patients an increased prevalence of thyroid disorders (78%), particularly non-toxic nodular goiter, has been observed. Thyroid volume, evaluated by ultrasonography, was correlated to the estimated duration of acromegaly. Finally, the prevalence of thyroid carcinoma was slightly increased than in the general population.