De quelques maux de la prévention contemporaine. Le cas de l’obésité et du surpoids

Overweight and obesity are considered major public health issues, and many preventive campaigns are designed to prevent unhealthy eating habits among the French. But these campaigns may be ineffective, and even sometimes counterproductive. Firstly, because prevention is a moral enterprise that can lead to stigmatizing targeted people. Secondly, because the ‘merchandization’ of prevention fuels a ‘dietary cacophony’. Thirdly, the medicalisation of overweight/obesity involves some shortcomings: it can prevent us from understanding eating habits, and many general physicians are insufficiently trained to take care of overweight or obese patients.     

Détection centrale des acides gras et contrôle du bilan d’énergie

Nutrient sensitive neurons (glucose and fatty acids (FA) are present in many sites throughout the brain, including the hypothalamus and brainstem, and play a key role in the neural control of energy and glucose homeostasis. Through neuronal output, FA may modulate feeding behaviour as well as both insulin secretion and action. For example, central administration of oleate inhibits food intake and glucose production in rats. This suggests that daily variations in plasma FA concentrations might be detected by the central nervous system as a signal, which contributes to the regulation of energy balance. At the cellular level, subpopulations of neurons in the ventromedial and arcuate hypothalamic nuclei are selectively either inhibited or activated by FA. Possible molecular effectors of these FA effects likely include chloride or potassium ion channels. While intracellular metabolism and activation of the ATP-sensitive K⁺ channel appear to be necessary for some of the signaling effects of FA, at least half of the FA responses in ventromedial hypothalamic neurons are mediated by interaction with FAT/CD36, a FA transporter/receptor that does not require intracellular metabolism to activate downstream signaling. Thus, FA or their metabolites can modulate neuronal activity as a means of directly monitoring ongoing fuel availability by brain nutrient-sensing neurons involved in the regulation of energy and glucose homeostasis. Besides these physiological effects, FA overload or metabolic dysfunction might impair neural control of energy homeostasis and contribute to obesity and/or type 2 diabetes in predisposed subjects.     

Comportements alimentaires de l’enfant et attitudes parentales: le point de vue de la psychologie expérimentale

Children show a clear preference, throughout development, for high energy density foods, and particularly for sweet and/or fat products. Most parents disapprove of this behavior, in the present context of high obesity prevalence and widespread acceptance of thinness as a model. Children’s appetite for such foods has adaptive value, so far as the growing child has not lost his/her ability for energy adjustment. A few studies suggest that excessive control over children’s food choices contributes to a loss of the child’s capacity to energy adjustment. Education models that include both the teaching of rules and adjustments to the child’s requests seem to facilitate the acquisition of adequate eating behaviors, which favor a varied diet and body weight control.     

Les acides gras : molécules informatives du contrôle nerveux de l’homéostasie énergétique

Free fatty acids (FFA) are not fuel for neurons and do not cross “easily” blood brain barrier. However, it is know well established that FFA could act as informative molecules and any change in plasma FFA concentration are detected at the level of central nervous system (CNS) structure such as hypothalamus and brainstem, where FFA sensitive neurons are located. These neurons control in turn energy homeostasis including food behaviour, hepatic glucose production or insulin secretion. Sub-populations of FFA sensitive neurons (either excited or inhibited) are now described in hypothalamus. Regarding, cell signaling, both acyl-CoA and malonyl-CoA could be major factor to mediate FFA effect. Indeed, increased intracellular concentration of malonyl-CoA in hypothalamus induce food intake inhibition. Such effects are partly related to decrease in NPY gene expression, as well as increase in alpha-MSH expression. Finally, dysregulation of FFA sensing in CNS could lead to development of metabolic diseases such as obesity or type 2 diabetes, in predisposed subject.     

Rôles physiologiques des endocannabinoïdes dans le contrôle de l’homéostasie énergétique

Endocannabinoids are endogenous lipids which modulate the release of neurotransmitters and activate different signaling pathways, through the binding to cannabinoïd receptors, CB1 and CB2. Endocannabinoids are involved in the control of a variety of behavioural and neuroendocrine functions, including feeding behaviour. In the central nervous system, they essentially modulate the expression of orexigen or anorexigen neuropeptides thus resulting in the stimulation of food intake. Their peripheral targets are mainly the liver and the white adipose tissue where they stimulate lipogenesis, through the modulation of several enzymes and proteins expressions. Cannabinoïd receptor agonists are nowadays prescribed to improve appetite of people suffering from cancer or AIDS. In the same way, CB1 antagonist, such as Rimonabant, could provide efficient treatment of obesity.     

Développement et validation d’une échelle de qualité de vie axée sur l’alimentation pour la population française

Dietary modifications are hard to achieve and maintain over time. They may affect the subject's quality of life. Very few scales have been developed and validated in French to measure the quality of life of healthy subjects. None of them are designed to specifically analyze quality of life as it relates to diet. Within the framework of the ELPAS study, an original scale (QV-AF) was developed to measure the effects of dietary coaching on food-related quality of life in healthy subjects. This scale underwent linguistic and psychometric validation. It may be freely used; scoring parameters are available upon request.     

La mesure du métabolisme de base reste fondamentale pour établir les apports énergétiques conseillés aux patients obèses

Three methods for evaluating the resting metabolic rate (RMR) in obese patients have been compared with the reference technique measurement: indirect calorimetry. The methods were the calculation of RMR by Harris and Benedict's and Black's formulas, and by bioelectrical impedance analysis (BIA). In the same patients, the level of recommended energetic intakes obtained from the dietetic evaluation was compared with the ideal level given by the calorimetric RMR. Bioelectrical impedance analysis and Harris and Benedict's formulas gave mean results non significantly different from indirect calorimetry, but with a high risk of dispersion, and they were consequently unusable in daily practice. Black's formulas significantly underestimated RMR. The dietetic evaluation proposed a too high level of energetic intakes, with a risk for the patients of inefficiency. The calorimetric RMR measurement is still a base for obtaining the level of energetic intakes recommended to obese patients.     

Fréquence et gravité des troubles du comportement alimentaire chez les jeunes diabétiques de type 1 : revue de la littérature

Eating disorders (ED) of young diabetics have been the subject of many publications for the last twenty years. They have been especially studied in the case of young girls in the pre-adolescent period or during adolescence. These eating disorders are part of DSM-IV classification: anorexia nervosa, bulimia nervosa or non other specified disorders (NOSD) where a clinical sign in the above mentioned diseases is lacking. An example of NOSD is “binge eating disorder”. Other more moderate ED, not classified in the DSM-IV have also been described. Ten case-control studies showed that anorexia nervosa does not appear frequently with diabetes, but when it does appear, mortality is very frequent. All the other ED are statistically more frequent with diabetes, especially binge eating disorder and the moderate ED which are not included in the DSM-IV. Purging behaviour, including insulin omission is equally frequent with young diabetics when weight must be controlled. This, will result in an increase of the HbA₁C and more of chronic complications, especially retinopathy. Two principal factors seem to enter into the appearance of the ED. First, weight, often higher than in control cases, where regulation can contribute to the apparition of ED to compensate for insulin omission. Then, bad familial environment, without really knowing if this is found more often with diabetes, or with ED control subjects. Several studies have shown that a follow up of ED is possible and efficient, but also, that ED are not always necessary in a certain number of cases, when more care is taken with young diabetics when the metabolic control is and continues to be mediocre.     

Place du diététicien dans l’équipe de soutien nutritionnel : évolution d’une profession

Recognised 30 years ago, hospital nutritional depletion remains a major problem of public health which concerns from 30% to 50% of all patients at admission. The circular DHOS/E 1 n? 2002-186 of the 29 March 2002, recommending the implementation of both the committee for food-nutrition (CLAN: Comité de Liaison Alimentation Nutrition) and the nutrition support team within the hospital, is the result of 10 years effort in regard to food-nutrition and the accreditation process in health care. The dietician, previously accountable for the quality of food and dietary services, has now the opportunity to play a leading role within the nutritional care team for the screening and treatment of nutritional depletion. However, the initial training and the present status of the dietician don’t allow him to follow this evolution effectively. Updating of his training and the redefinition of his missions seem indispensable to respond to today's health care needs. This will help to ensure that above legal recommendation can be applied.     

Connaissances nutritionnelles relatives aux lipides et croyances de santé chez 1 595 sujets hypercholestérolémiques

There is still a paucity of data analysing the specific features of representations of cholesterol and nutrition knowledge among hypercholesterolemic subjects. The knowledge and personal opinions of 1579 hypercholesterolemic patients (58% males; mean age: 58.3 years), recruited by their general practitioners, were analysed on the basis of the responses to a self-administered questionnaire. In a list of 11 foods, patients were asked to choose among three proposals: the food directly brings cholesterol to the body, the food is rich in fat which increases serum cholesterol levels and the food neither brings cholesterol nor contains fat which increases serum cholesterol levels.Correct answers were frequent for butter, meat, vegetables whereas incorrect answers were frequent for oils, and peanuts (which were considered as cholesterol rich foods). We did not find any strong correlations between the level of nutrition knowledge and gender, age and risk factors. In contrast, there was a strong relationship between educational level and nutrition knowledge. In comparison with subjects with a good nutrition knowledge, those who gave the highest percentage of wrong answers expressed the most misconceptions concerning hypercholesterolemia and its attendant risks and were the least convinced by and motivated for treatment. Finally we also identified health locus control as a major determinant of nutrition knowledge.Our findings attest to the need to support educational and informational messages. In order to heighten the impact of such efforts, it would seem necessary to target specific messages according to educational level and health locus control.     

La néoglucogenèse intestinale: un nouvel acteur du contrôle de la prise alimentaire

Introduction: The interactions between glucose and energy homeostasis are well known, especially regarding the suppressing role on food intake of glucose into the portal vein.Material and Methods: The expression of genes of gluconeogenesis was characterized at the level of mRNA, protein, and enzymatic activity. Intestinal glucose production was quantified using a combination of (3-³H) glucose tracer dilution and arterio-venous glucose balance. The effect of portal glucose on food intake was studied using conscious rats with indwelling catheters into the portal vein. The effect of infusions at the hypothalamus level was studied by immunodetection of the protein c-Fos.Results: All regulatory genes of gluconeogenesis are expressed in the small intestine from rat and human. They are strongly induced in rat: during fasting; and by protein-enriched diet. In both cases, this promotes glucose release in the portal vein, lasting after the postprandial period for the protein-enriched regimen. The infusion of glucose at comparable rates into the portal vein decreases food intake in rat, and activates the hypothalamic regions involved in the control of food intake, just as does the protein enriched diet.Conclusion: These results provide a mechanistic explanation for the effect of satiety induced by diet protein, well known to occur in animals and humans, but unsolved up to now.     

Un colis de référence pour une aide alimentaire équilibrée

Practical and specific guidelines are needed to design nutritionally adequate food baskets for food aid. Since the weight of foods is the only information on food easily available and understandable by non nutritionist field-workers, weight-based guidelines were presently developed. They are compatible with the French food-based dietary guidelines and take into account that food-insecure individuals have limited access to some foods, such as meat, fish, fruit and vegetables, while refined cereals are the main component of their diets. These guidelines can also be used to evaluate the dietary quality of existing food aid. factual food baskets delivered by food aid agencies in France were compared to the recommended food basket. The results show that fruit and vegetables are severely lacking (only 10% of total food basket weight instead of 33% recommended) while staples, mainly refined cereals, are given in excess (40% instead of 15%), as well as sugar- or salt-containing food products (9% instead of 2%). This results show that it is necessary to improve the dietary quality of food aid in France and suggest that simple weight-based recommendations can be helpful.     

Les systèmes et niveaux de détermination du comportement alimentaire

Eating behaviours are ruled simultaneously by physiological; psychological, technical, social, and economic systems. In practice, human subjects manage the complexity of these multiple determinants by following mental and technical routines, which progressively incorporate the results of experience. Social representations are a key mode of transmission and guidance of behaviour; a kind of user’s manual of everyday objects. To modify behaviour, one has to act simultaneously upon all levels of determination in order to open new behavioural paths, and this can be done only in collaborative process involving all stakeholders.     

L’endothéliopathie : son risque et rôle des facteurs métaboliques

Endothelial dysfunction (ED) has been demonstrated in diabetics, insulin resistant obese patients, patients with hypercholesterolemia or hypertension, and also in smokers. The role played by hyperglycemia, and an excess in free fatty acids and leptin has been evoked. ED may be considered as a vascular integrator of various metabolic disorders and some nutritional factors. Evidence for ED is based on pharmacological tests using acetylcholine in particular, or functional tests like the forearm-mediated vasodilation, but also on the measurement of blood markers or microalbuminuria. ED plays a pathophysiological role in atherothrombosis, tissue ischemia, hypertension and microangiopathic complications of diabetes. ED is an ubiquitous disorder which involves the whole artery network and microcirculation. ED may also contribute to insulin resistance. It may be reversed when improving metabolic disorders and lowering blood pressure. In addition, some oral hypoglycemic agents, lipid or blood pressure lowering drugs are able to improve endothelium function through pleiotropic effects. Various antioxidant agents exert also short-term beneficial effects on the endothelium but their therapeutic effects remain to be defined.     

Transmission du cytomégalovirus chez les enfants prématurés par le lait maternel cru

This study evaluated the kinetics of CMV load in breastmilk and the rate of postnatal CMV transmission via breastmilk from mothers to their preterm infants.

Methods

Prospective study of mother-child pairs after preterm delivery before 33 weeks. Material used was maternal CMV serostatus, ear swab of the infant at birth, weekly screened breastmilk and children’s urine by rapid viral culture.

Results

During a 5 month period 28 mother-infant pairs with 34 preterm infants were studied. Eighteen women (64.3%) were CMV-seronegative at birth; breastmilk samples and the infants’ urine remained CMV-negative. Eight of the 10 seropositive mothers, who had 11 preterm infants, excreted CMV into breastmilk (80%). Out of the 7 CMV-exposed infants, CMV transmission was confirmed in only one asymptomatic case.

Conclusion

In CMV-seropositive mothers of preterm infants a high incidence of CMV excretion into breastmilk was detected. Despite this high rate, symptomatic infection did not occur. Because breastfeeding is beneficial, new procedures for gentle virus inactivation of seropositive breastmilk should be assessed.     

Mesure de l’efficacité et de l’observance du traitement antirétroviral chez des patients infectés par le VIH au Cameroun

Objective

The aim of the study was to identify the most useful clinical criteria to measure effectiveness and adherence to antiretroviral treatment in a rural area of Cameroon.

Patients and method

All patients under antiretroviral therapy followed for at least 3 months at the Tokombéré UPEC hospital were eligible. Therapeutic failure was defined according to clinical criteria including weight, Karnofsky's index, or occurrence of WHO stage IV conditions. The criteria for drug adherence were based on patient statement (drugs taken over the last 4 days) and pharmacy-controlled drug delivery. Patient sociodemographic characteristics were collected via a questionnaire.

Results

Fifty-six patients were included, most of whom were at AIDS stage on treatment initiation. The mean duration of antiretroviral therapy was 1 year. 21, 10, and 19% of patients were in therapeutic failure according to “weight”, “Karnofsky's index”, and “WHO stage IV”, respectively. Non-adherence was reported in 5% of patients according to the declarative method and 20% according to pharmacy controlled drug delivery. Weight modification during treatment was significantly correlated with the evolution of Karnofsky's index (p = 0.03). A significant correlation between therapeutic failure and non-observance was only found when using the weight criterion and the declarative method (p = 0.004).

Conclusion

The effectiveness and adherence to antiretroviral therapy can be evaluated by simple clinical criteria. Using these criteria can be recommended in rural areas until access to biological follow-up becomes available in developing countries.     

Consommation de produits laitiers et facteurs de risque cardiovasculaire dans l′étude MONICA

The aim of this study was to assess the associations between dairy products and cardiovascular risk factors in a representative sample of the French population. A sample of 912 men aged 45-64 years was randomly selected from the general population in Northern (Lille), Eastern (Strasbourg) and South-Western (Toulouse) regions of France. Risk factors were evaluated in each participant who completed a three-consecutive-day food record. In statistical analysis, subjects were separated according to quintiles of daily dairy product consumption. From the lowest quintile to the highest quintile of dairy product consumption and after adjustment for center, age, energy intake, alcohol, sodium, magnesium, and antihypertensive and antidiabetic treatments, systolic blood pressure significantly decreased. The prevalence of the metabolic syndrome decreased significantly from 32.6% to 25.0%, 21.8%, 18.3% and 19.9% (p=0.02 after adjustment for center, age, energy intake, alcohol, sodium, magnesium, and antihypertensive and antidiabetic treatments). In conclusion, high consumption of dairy products is associated with lower levels of blood pressure and a lower prevalence of the metabolic syndrome.     

Quelques aspects de la motivation à manger en fonction de l’index de masse corporelle (de la maigreur à l’obésité massive) dans un groupe de 2 509 adultes

This study examines how chronic dietary restraint, disinhibition, and hunger, as assessed by the Eating Inventory (also called the “Three Factor Eating Questionnaire”), vary over a broad range of Body Mass Index (BMI) values from leanness to massive obesity, in subjects with family obesity. EI factors were also studied as a function of personal weight history. Subjects were 2509 participants in a genetic study of obesity. BMIs ranged from 15 to 87kg/m². Multivariate analyses showed that restraint and disinhibition were significantly associated with the BMI in men, while only disinhibition was in women. Further analyses were performed after subdividing the population in 6 BMI groups. Disinhibition scores correlated strongly with hunger scores in both genders in all BMI categories; dietary restraint tended to correlate with the other two factors positively in leaner subjects, and negatively in highest BMI categories. The highest restraint scores were observed in nonobese adult women with previous obesity in childhood and/or adolescence, suggesting a beneficial influence of restraint on body weight loss. The role of behaviors associated with disinhibition in the development of body adiposity deserves further investigation.     

Pauvreté, monoparentalité et alimentation: Une étude de cas dans le nord de la France

The survey was carried out in the North of France. Its purpose was to examine the link between poverty and food. The results underline that the marital and social situations of the interviewed persons were more important to understand their meal patterns, than their low level of resources. When the spouse is left, there is no more familial interest to have meal together, and then we observed that women spend less time to cook. On the opposite, food can, in other cases, play a positive role in dealing with poverty. Thus, provisioning and cooking appear as social activities which allow isolated people to keep a social life. In both cases, the meal is maintained, and the difference sets at the level of preparation. In conclusion, the article invites to reconsider the ways of cooking in poverty situations. It suggests that we should change the representations of an elaborate meal which doesn’t necessarily needs fresh products, but also appertized and frozen products. In this way, we should partly solve the constraint of cost and time of preparation.     

Effets d’âge et de génération : transformation du modèle alimentaire

The traditional food model of French resting on user-friendliness, food diversity, the regularity of the schedules of the meals… is less and less followed by the younger generations. By these generational changes, one attends not with a disappearance of the French food model or with a destructuration of the meals but a modification of this model: reduction in the number of dishes and the make-ready times, irregularity of the schedules of meal, increase in the tray meals and rise of products the processed and flat exotics with the detriment of the basic commodities. This evolution answers the modifications of the ways of life which require saving of time, praticity and convenience. This basic trend is accompanied by a concern growing with respect to the health which gains all the generations and results in a strong growth of the market segments of the food health. The third dimension of the food triptych is the basic base of the French food which perdure in new forms: pleasure in the food. It results in the development of the invitations at home in the form of aperitifs dînatoires and of the kitchen leisures which takes form through the courses of kitchen.