Effects of a Weight Loss Program on Metabolic Syndrome, Eating Disorders and Psychological Outcomes: Mediation by Endocannabinoids?

OBJECTIVE: To evaluate the effects of weight loss on endocannabinoids, cardiometabolic and psychological parameters, eating disorders (ED) as well as quality of life (QoL) and to elucidate the role of endocannabinoids in metabolic syndrome (MS). METHODS: In total, 114 patients with obesity were prospectively included in a 12-month weight loss program. Plasma endocannabinoids were measured by mass spectrometry; ED, psychological and QoL-related parameters were evaluated by self-reported questionnaires; physical activity was measured by accelerometer. Nutritional assessment was done by a 3-day food diary. RESULTS: Among completers (n = 87), body weight decreased in 35 patients (-9.1 ± 8.6 kg), remained stable in 39 patients, and increased in 13 patients (+5.8 ± 3.4 kg). 75% of patients with MS at baseline were free of MS at follow-up, and their baseline plasma N-palmitoylethanolamide (PEA) values were significantly lower when compared to patients with persisting MS. At baseline, there was a positive relationship between PEA and waist circumference (p = 0.005, R2 = 0.08), fasting glucose (p < 0.0001, R2 = 0.12), total cholesterol (p = 0.001, R2 = 0.11), triglycerides (p = 0.001, R2 = 0.11), LDL-cholesterol (p = 0.03, R2 = 0.05) as well as depression score (p = 0.002, R2 = 0.29). CONCLUSION: Plasma PEA might play a role in metabolic improvement after weight loss. Even in subjects without weight loss, a multidisciplinary intervention improves psychological outcomes, ED, and QoL.

Involvement of dietary Fatty acids in multiple biological and psychological functions, in morbidly obese subjects.

BACKGROUND: Fatty acid (FA) profile is often altered, in morbidly obese subjects, both before and after bariatric surgery. We measured FA plasma levels before and 6 months after Roux-en-Y gastric bypass (RYGB), in order to evaluate their relationship with different biological and psychological parameters and the impact of RYGB on the FA plasma levels. METHODS: Thirty eight morbidly obese patients were investigated before RYGB, and 28 of them were reexamined 6 months postoperatively. Anxiety, depression, and quality of life were evaluated by validated questionnaires. Plasma FA (saturated, monounsaturated, polyunsaturated ω-6 and ω-3), vitamins A and E, fasting insulinemia, and high-sensitive C-reactive protein (hs-CRP) were measured. RESULTS: Before surgery, ω-3 polyunsaturated FA and vit A showed significant negative relationship with fasting insulinemia (γ-linolenic p = 0.03, eicosapentaenoic, vit A p = 0.01) and hs-CRP (eicosapentaenoic p = 0.03, vit A p = 0.02) and a positive link with HDL cholesterol (γ-linolenic p = 0.03, vit A p = 0.02). Depression score was significantly and negatively linked with palmitoleic (p = 0.03), γ-linolenic (p = 0.006), dihomo-γ-linolenic (p = 0.02), and α-linolenic (p = 0.03) acids. After surgery, FA and both vit A and E were significantly reduced. Vit A levels were below 2.4 µmol/l in 63 % of the patients, preoperatively, and in 79 % after surgery. Preoperative levels of linoleic acid were significantly related with the postoperative weight reduction (p = 0.0006). CONCLUSIONS: FA are involved in several biological and psychological functions. The RYGB-induced reduction of FA could have deleterious consequences on vitamin absorption, metabolism, and depression. Thus, the surveillance of FA levels is of primary importance both before and after RYGB.

Off-label prescriptions: how to identify them, frame them, announce them and monitor them in practice?

Following the Mediator crisis and the passage of the Health and Safety Law of December 2011, off-label prescriptions are a real concern shared by all those involved in healthcare system. Off-label, in the strictest sense of the term, is defined as all prescriptions that do not correspond to the summary of product characteristics (SPC), particularly those that fail to comply with the indications and dosage regimens defined by the marketing authorization (MA) for clear safety reasons. There are various rasons for off-label prescriptions, both conscious and unconscious. They are intended to respond to unmet medical needs, the needs of poorly studied populations or not studied at all in trials, but in relation to whom it is reasonable to extrapolate that MA would be given (common-sense prescriptions) and, additionally, to urgent public health needs (such as baclofen, pregnant women, and HIV drugs). All these prescriptions would deserve to be studied for a potential MA. However, there are off-label prescriptions that need to be restricted or even penalized in the case of compassionate prescriptions or unjustified prescriptions or prescriptions not based on any scientific grounds. Off-label prescriptions are not easy to track down because if the prescriber has to write "off-label" on his prescription, then clearly, in practice, he will only do so in exceptional cases. Neither the pharmacists who dispense the drug nor the Social Security that reimburses it, have access to the diagnosis (or targeted indication). Thus, in order to identify the off-label prescription, we must be able to cross reference the available databases (such as pharmacovigilance database, medicalized information system program [programme de médicalisation des systèmes d'information, PMSI], hospital drug formularies, general sample of beneficiaries [échantillon généraliste de bénéficiaires, EGB] or national inter-regional Health Insurance Information System [système national d'informations inter-régions d'Assurance maladie, SNIIRAM], sales data, and data from market surveys). The shared computerized patient file may resolve this problem. The temporary use recommendation (TUR) proposed by the Drug Safety Law will only partially deal with this problem for recently marketed molecules. This temporary and exceptional mechanism will authorize a recognized off-label prescription, which may be reimbursed and monitored for 3 years. These TURs will only concern a small portion of "off-label" drugs having yet a positive risk/benefit ratio (conditional MA) but this is far from matching with majority of off-label prescriptions. As such, and in order to improve the use of drugs, it is important to propose a control system for all "off-label" prescriptions with a dedicated committee: the "off-label" committee which would determine the frame of the "off-label" prescriptions.

[The endocannabinoid system in obesity]. / Le système endocannabinoïde dans l'obésité.

The endocannabinoid system is involved in the regulation of energy balance and metabolism. Endocannabinoids have central effects with raising appetite and hunger. On the other hand, different components of the endocannabinoid system are also found in peripheral organs and tissues and they could impact the lipid and glucose metabolism. Obesity is associated with an overactivity of the endocannabinoid system with increased both plasmatic and visceral adipose tissue levels. The amount of the intra-abdominal fat mass is an indicator of the peripheral endocannabinoid system dysregulation. Endocannabinoids-like molecules with more pronounced peripheral effects on lipids and glucose metabolism could be a new target of obesity treatment.

[Micronutrient deficiency in obesity]. / Déficiences micronutritionnelles chez les patients obèses.

Obesity is frequently associated with micronutrient deficiency due to unhealthy diet, lack of antioxidants and polyunsaturated fat on one side and abundance of saturated fat on the other side. The micronutrients play an important role in inflammation, metabolic syndrome and insulin resistance and could influence the weight loss. The screening of micronutrient deficiency should therefore be systematic in order to improve the management of obesity. This is of particular importance for bariatric surgery patients.

Effect of obesity on growth-related oncogene factor-alpha, thrombopoietin, and tissue inhibitor metalloproteinase-1 serum levels.

We have recently identified several adipokines as oversecreted by omental adipose tissue (AT) of obese subjects: two chemokines (growth-related oncogene factor-alpha (GRO-alpha), macrophage inflammatory protein-1 beta (MIP-1 beta)), a tissue inhibitor of metalloproteinases-1 (TIMP-1), an interleukin-7 (IL-7) and a megakaryocytic growth-factor (thrombopoietin (TPO)). These adipokines are involved in insulin resistance and atherosclerosis. The objectives of this study were to determine whether the circulating levels of these adipokines were increased in obesity and to identify the responsible factors. A cross-sectional study including 32 lean (BMI (kg/m(2)) <25), 15 overweight (BMI: 25-29.9), 11 obese (BMI: 30-39.9), and 17 severely obese (BMI >40) age-matched women was carried out. Serum adipokine levels, insulin sensitivity, and substrate oxidation were measured by ELISA, euglycemic-hyperinsulinemic clamp, and indirect calorimetry, respectively. Circulating levels of GRO-alpha, TPO, and TIMP-1 were higher in obese and/or severely obese women than in lean ones (+30, 55, and 20%, respectively). Serum levels of these adipokines positively correlated with insulinemia or glycemia, and negatively with insulin sensitivity. TIMP-1 also positively correlated with blood pressure, and TPO with triglyceride levels. Multiple regression analysis showed that fat mass per se was an independent determinant of GRO-alpha, TPO, and TIMP-1 levels, suggesting that hypertrophied adipocytes and recruited macrophages in expanded AT mainly contribute to this hyperadipokinemia. Insulinemia, glycemia and resistance of glucose oxidation to insulin were additional predictors for TPO. Circulating GRO-alpha, TPO, and TIMP-1 levels are increased in obesity. This may be partially due to augmented adiposity per se and to hyperinsulinemia/insulin resistance. These high systemic levels may in turn worsen/promote insulin resistance and cardiovascular disease.

Role of intraoperative neuromonitoring of the recurrent laryngeal nerve in high-risk thyroid surgery.

BACKGROUND: Thyroid surgeries associated with an elevated incidence of recurrent laryngeal nerve (RLN) injury are considered high-risk thyroidectomies. These high-risk operations include surgery for thyroid cancer, Graves disease, and recurrent goitre. In addition, the size of the goitre is an important risk factor for RLN injury. OBJECTIVE: In our retrospective study, we tried to evaluate the role of intraoperative neuromonitoring of RLN specifically in high-risk thyroid surgery with 421 nerves at risk. METHOD: Thyroid surgeries in our study were done by experienced surgeons in a high-volume provider centre.The overall percentage of RLN injury was 8.8% in the monitored group in comparison with 9.1% in the unmonitored group. The percentage of permanent nerve palsy in the monitored group was 3.9% of nerves at risk in comparison with 3.8% in the unmonitored group. No statistically significant difference was found between groups. CONCLUSION: Routine visual identification of the nerve by meticulous dissection is the best method to avoid RLN injury. The benefit of RLN neuromonitoring could be further assessed by performing a multicentre prospective study to compare the role of RLN neuromonitoring in high-risk thyroid surgeries.

[Gut microbiota, responsible for our body weight?]. / La flore intestinale, responsable de notre poids?

Obesity is a multifactorial disease and often considered as an imbalance between energy intake and energy expenditure. However, the gut microbiota could have an impact on the development of excess body weight. According to the type of diet, this black box of the bowel could contribute to modifications of both the caloric extraction and the energy expenditure. The gut microbiota is linked with intermediary metabolism and inflammation, and could be involved in physiopathogenesis of type 1 and 2 diabetes, metabolic syndrome and obesity. Fiber enriched diet and Mediterranean type of diet could induce gut microbiota modifications with consecutive weight loss and improvement of both metabolic syndrome and diabetes.

Analyzing stochastic transcription to elucidate the nucleoid's organization.

BACKGROUND: The processes of gene transcription, translation, as well as the reactions taking place between gene products, are subject to stochastic fluctuations. These stochastic events are being increasingly examined as it emerges that they can be crucial in the cell's survival. In a previous study we had examined the transcription patterns of two bacterial species (Escherichia coli and Bacillus subtilis) to elucidate the nucleoid's organization. The basic idea is that genes that share transcription patterns, must share some sort of spatial relationship, even if they are not close to each other on the chromosome. We had found that picking any gene at random, its transcription will be correlated with genes at well-defined short - as well as long-range distances, leaving the explanation of the latter an open question. In this paper we study the transcription correlations when the only transcription taking place is stochastic, in other words, no active or "deterministic" transcription takes place. To this purpose we use transcription data of Sinorhizobium meliloti. RESULTS: Even when only stochastic transcription takes place, the co-expression of genes varies as a function of the distance between genes: we observe again the short-range as well as the regular, long-range correlation patterns. CONCLUSION: We explain these latter with a model based on the physical constraints acting on the DNA, forcing it into a conformation of groups of a few successive large and transcribed loops, which are evenly spaced along the chromosome and separated by small, non-transcribed loops. We discuss the question about the link between shared transcription patterns and physiological relationship and come to the conclusion that when genes are distantly placed along the chromosome, the transcription correlation does not imply a physiological relationship.

Comments on selected fundamental aspects of microarray analysis.

Microarrays are becoming a ubiquitous tool of research in life sciences. However, the working principles of microarray-based methodologies are often misunderstood or apparently ignored by the researchers who actually perform and interpret experiments. This in turn seems to lead to a common over-expectation regarding the explanatory and/or knowledge-generating power of microarray analyses. In this note we intend to explain basic principles of five (5) major groups of analytical techniques used in studies of microarray data and their interpretation: the principal component analysis (PCA), the independent component analysis (ICA), the t-test, the analysis of variance (ANOVA), and self organizing maps (SOM). We discuss answers to selected practical questions related to the analysis of microarray data. We also take a closer look at the experimental setup and the rules, which have to be observed in order to exploit microarrays efficiently. Finally, we discuss in detail the scope and limitations of microarray-based methods. We emphasize the fact that no amount of statistical analysis can compensate for (or replace) a well thought through experimental setup. We conclude that microarrays are indeed useful tools in life sciences but by no means should they be expected to generate complete answers to complex biological questions. We argue that even well posed questions, formulated within a microarray-specific terminology, cannot be completely answered with the use of microarray analyses alone.

Decoding the nucleoid organisation of Bacillus subtilis and Escherichia coli through gene expression data.

BACKGROUND: Although the organisation of the bacterial chromosome is an area of active research, little is known yet on that subject. The difficulty lies in the fact that the system is dynamic and difficult to observe directly. The advent of massive hybridisation techniques opens the way to further studies of the chromosomal structure because the genes that are co-expressed, as identified by microarray experiments, probably share some spatial relationship. The use of several independent sets of gene expression data should make it possible to obtain an exhaustive view of the genes co-expression and thus a more accurate image of the structure of the chromosome. RESULTS: For both Bacillus subtilis and Escherichia coli the co-expression of genes varies as a function of the distance between the genes along the chromosome. The long-range correlations are surprising: the changes in the level of expression of any gene are correlated (positively or negatively) to the changes in the expression level of other genes located at well-defined long-range distances. This property is true for all the genes, regardless of their localisation on the chromosome. We also found short-range correlations, which suggest that the location of these co-expressed genes corresponds to DNA turns on the nucleoid surface (14-16 genes). CONCLUSION: The long-range correlations do not correspond to the domains so far identified in the nucleoid. We explain our results by a model of the nucleoid solenoid structure based on two types of spirals (short and long). The long spirals are uncoiled expressed DNA while the short ones correspond to coiled unexpressed DNA.

Familial correlations and inter-relationships of four asthma-associated quantitative phenotypes in 320 French EGEA families ascertained through asthmatic probands.

Asthma is a complex disease, associated with biological and physiological phenotypes including immunoglobulin E (IgE) levels, sum of positive skin prick tests to allergens (SPTQ), eosinophil counts (EOS) and percent predicted forced expiratory volume in 1 s (%FEV1). We investigated the patterns of familial correlations and the inter-relationships of these four quantitative phenotypes, using the general class D regressive model, in 320 French EGEA nuclear families ascertained through 204 offspring (set A) and 116 parents (set B). Familial correlations of IgE and SPTQ were consistent with a model including no spouse correlation and equal parent-offspring and sib-sib correlations (rhoPO = rhoSS = 0.25 for IgE and 0.15 for SPTQ), this model being compatible with an additive polygenic model in the whole sample and the two family subsets A and B. Different patterns of familial correlations of EOS and %FEV1 were observed in these two sets. In set A, the best fitting model included no spouse correlation and equality of parent-offspring and sib-sib correlations (rhoPO = rhoSS = 0.14 for EOS and 0.23 for %FEV1). In set B, EOS had only a significant rhoSS of 0.28, while %FEV1 had significant rhoMO of 0.28 and rhoSS of 0.16. Analysis of shared familial determinants between these phenotypes indicated an overlap of at most 30% in rhoFO for IgE and SPTQ and in both rhoFO and rhoMO for IgE and EOS, while determinants of %FEV1 and atopy-related phenotypes appear distinct. These results may have implications for further linkage and association studies with genetic markers.

The operons, a criterion to compare the reliability of transcriptome analysis tools: ICA is more reliable than ANOVA, PLS and PCA.

The number of statistical tools used to analyze transcriptome data is continuously increasing and no one, definitive method has so far emerged. There is a need for comparison and a number of different approaches has been taken to evaluate the effectiveness of the different statistical tools available for microarray analyses. In this paper, we describe a simple and efficient protocol to compare the reliability of different statistical tools available for microarray analyses. It exploits the fact that genes within an operon exhibit the same expression patterns. In order to compare the tools, the genes are ranked according to the most relevant criterion for each tool; for each tool we look at the number of different operons represented within the first twenty genes detected. We then look at the size of the interval within which we find the most significant genes belonging to each operon in question. This allows us to define and estimate the sensitivity and accuracy of each statistical tool. We have compared four statistical tools using Bacillus subtilis expression data: the analysis of variance (ANOVA), the principal component analysis (PCA), the independent component analysis (ICA) and the partial least square regression (PLS). Our results show ICA to be the most sensitive and accurate of the tools tested. In this article, we have used the protocol to compare statistical tools applied to the analysis of differential gene expression. However, it can also be applied without modification to compare the statistical tools developed for other types of transcriptome analyses, like the study of gene co-expression.