Association between weight perception and socioeconomic status among adults in the Seychelles.

BACKGROUND: Few studies have examined the association between weight perception and socioeconomic status (SES) in sub-Saharan Africa, and none made this association based on education, occupation and income simultaneously. METHODS: Based on a population-based survey (n = 1255) in the Seychelles, weight and height were measured and self-perception of one's own body weight, education, occupation, and income were assessed by a questionnaire. Individuals were considered to have appropriate weight perception when their self-perceived weight matched their actual body weight. RESULTS: The prevalence of overweight and obesity was 35% and 28%, respectively. Multivariate analysis among overweight/obese persons showed that appropriate weight perception was directly associated with actual weight, education, occupation and income, and that it was more frequent among women than among men. In a model using all three SES indicators together, only education (OR = 2.5; 95% CI: 1.3-4.8) and occupation (OR = 2.3; 95% CI: 1.2-4.5) were independently associated with appropriate perception of being overweight. The OR reached 6.9 [95% CI: 3.4-14.1] when comparing the highest vs. lowest categories of SES based on a score including all SES indicators and 6.1 [95% CI: 3.0-12.1] for a score based on education and occupation. CONCLUSIONS: Appropriately perceiving one's weight as too high was associated with different SES indicators, female sex and being actually overweight. These findings suggest means and targets for clinical and population-based interventions for weight control. Further studies should examine whether these differences in weight perception underlie differences in cognitive skills, healthy weight norms, or body size ideals.

Exercise and postprandial thermogenesis in obese women before and after weight loss.

The magnitude of thermogenesis induced by a test meal (17% protein, 54% CHO, and 29% fat) was assessed using indirect calorimetry in six obese women before and after weight loss (mean loss: 11.2 kg) and compared with six nonobese matched controls at rest for 5 h and during and following graded moderate exercise on a bicycle ergometer at three workloads. The test meal contained 60% of the energy expended in basal state over 24 h (736-1020 kcal/meal according to the group). In obese subjects the net absolute increase in energy expenditure (delta EE) in response to the meal was similar between exercising and resting conditions (delta EE = 0.27 vs 0.32 kcal/min, respectively) but tended to be lower in obese women after weight loss (delta EE = 0.19 kcal/min while exercising and 0.25 kcal/min while resting, p less than 0.05) and in control subjects (delta EE = 0.16 vs. 0.25 kcal/min, respectively: p less than 0.05). These results show that the thermogenic response to a meal is not potentiated by moderate exercise.

Hypolipidemic therapeutics and muscle metabolism

Summary : Lipid metabolism disorders, leading to obesity and cardiovascular diseases, are a major public health issue worldwide. These diseases have been treated by drugs and surgery, leading to tremendous costs and secondary morbidity. The aim of this thesis work is to investigate the mechanisms of actions of a new, micronutrition-based, approach to prevent obesity and cardiovascular diseases. This specific combination of micronutrients, Lipistase, incorporated into any dietary ail can be used in the daily food. Micronutrients are substances used by the living organism in small quantities to maintain physiological homeostasis. However, the human body is not able to produce them and has to obtain them from dietary sources. The combination of micronutrients investigated here, is composed of 26 compounds including trace elements, vitamins, minerals, ails and plant extracts, known to have individually a beneficial effect on lipid metabolism regulation. These specific micronutrients are used for the first time in a combinatorial mode targeting several metabolic pathways for better homeostasis control as opposed to a single target treatment, either chemical or natural. Short and long term studies, in different mouse strains, showed a significant decrease in plasma triglycerides, body weight gain and body fat mass in animals that were fed with a standard diet containing Lipistase. Additionally, a greatly reduced fat accumulation was observed in adipose tissue and liver of Lipistase-treated animals, while lipid and glucose utilization by skeletal muscle was enhanced. Moreover, the size of atherosclerotic plaques was significantly reduced in mice whose masher was treated during pregnancy and suckling, without showing any adverse effect. Finally, Lipistase has been shown to increase longevity by 20%. The control mice that did not receive Lipistase in their diet did not show all these beneficial effects. These micronutrients are used at the lowest dosage ever reported for treating Lipid disorders, resulting in far much lower costs as well as probably a higher safety. This is the first approach being very suitable for an effective large scale prevention policy for obesity and cardiovascular diseases, like iodine in dietary salt has been for goiter. Résumé : Les dysrégulations du métabolisme des lipids, à l'origine d'obésité et de maladies cardiovasculaires, sont un problème de santé publique majeur et mondial. Ces maladies impliquent des traitements médicamenteux et chirurgicaux dont le coût la morbidité secondaire sont très important. Le but de ce travail de thèse est d'étudier les mécanismes d'action d'une nouvelle approche préventive, basée sur la micronutrition. Cette combinaison spécifique de micronutriments, Lipistase, peut être incorporée dans n'importe quelle huile alimentaire et utilisée dans l'alimentation quotidienne. Les micronutrirnents sont des substances essentielles, à très faibles doses, pour le maintien de l'homéostasie physiologique des organismes vivants. Cependant, étant incapable de les synthétiser, le corps humain est dépendant en cela de l'apport alimentaire. La combinaison de micronutriments que nous avons étudié contient 26 composants, incluant des extraits de plantes, des huiles, des vitamines, des métaux et des minéraux, tous connus pour avoir individuellement des effets bénéfiques sur la régulation du métabolisme des lipides. Ces micronutriments spécifiques sont utilisés pour la première fois en mode combinatoire, ciblant ainsi plusieurs voies métaboliques pour un meilleur control de l'homéostasie, par opposition monothérapies chimiques ou naturelles. Des expériences de court et long terme, avec divers modèles de souris, ont montré une diminution significative des taux de triglycérides plasmatiques, de la prise de poids et de la masse graisseuse corporelle chez les animaux qui ont reçu Lipistase dans la nourriture standard. Une accumulation significativement moins importante des graisses a été observée dans le tissu adipeux et hépatique des souris traitées, alors que l'utilisation des lipides et glucose a été favorisée dans le muscle. En outre, la taille des plaques d'athérosclérose aété significativement réduite chez les souris dont la mère a été traitée pendant la grossesse et l'allaitement, sans montrer aucun effet indésirable. Enfin, les souris traitées par Lipistase ont vécu 20% plus longtèmps. Les souris contrôles qui n'ont pas reçu Lipistase dans la nourriture n'ont montré aucun de ces effets bénéfiques. Ces micronutriments sont utilisés au dosage le plus faible jamais rapporté pour le traitement des maladies du métabolisme lipidique, permettant ainsi un coût plus faible et surtout une meilleure sécurité. C'est une approche adéquate pour une politique de prévention de santé publique à large échelle de l'obésité et des maladies cardiovasculaires. C'est en cela et sous bien d'autres aspects, une première dans la prise en charge des maladies du métabolisme lipidique et pourrait même être pour ces dernières ce que l'iode du sel de cuisine a été pour le goitre.

Introducing systematic dispatcher-assisted cardiopulmonary resuscitation (telephone-CPR) in a non-Advanced Medical Priority Dispatch System (AMPDS): implementation process and costs.

OBJECTIVE: In order to improve the quality of our Emergency Medical Services (EMS), to raise bystander cardiopulmonary resuscitation rates and thereby meet what is becoming a universal standard in terms of quality of emergency services, we decided to implement systematic dispatcher-assisted or telephone-CPR (T-CPR) in our medical dispatch center, a non-Advanced Medical Priority Dispatch System. The aim of this article is to describe the implementation process, costs and results following the introduction of this new "quality" procedure. METHODS: This was a prospective study. Over an 8-week period, our EMS dispatchers were given new procedures to provide T-CPR. We then collected data on all non-traumatic cardiac arrests within our state (Vaud, Switzerland) for the following 12months. For each event, the dispatchers had to record in writing the reason they either ruled out cardiac arrest (CA) or did not propose T-CPR in the event they did suspect CA. All emergency call recordings were reviewed by the medical director of the EMS. The analysis of the recordings and the dispatchers' written explanations were then compared. RESULTS: During the 12-month study period, a total of 497 patients (both adults and children) were identified as having a non-traumatic cardiac arrest. Out of this total, 203 cases were excluded and 294 cases were eligible for T-CPR. Out of these eligible cases, dispatchers proposed T-CPR on 202 occasions (or 69% of eligible cases). They also erroneously proposed T-CPR on 17 occasions when a CA was wrongly identified (false positive). This represents 7.8% of all T-CPR. No costs were incurred to implement our study protocol and procedures. CONCLUSIONS: This study demonstrates it is possible, using a brief campaign of sensitization but without any specific training, to implement systematic dispatcher-assisted cardiopulmonary resuscitation in a non-Advanced Medical Priority Dispatch System such as our EMS that had no prior experience with systematic T-CPR. The results in terms of T-CPR delivery rate and false positive are similar to those found in previous studies. We found our results satisfying the given short time frame of this study. Our results demonstrate that it is possible to improve the quality of emergency services at moderate or even no additional costs and this should be of interest to all EMS that do not presently benefit from using T-CPR procedures. EMS that currently do not offer T-CPR should consider implementing this technique as soon as possible, and we expect our experience may provide answers to those planning to incorporate T-CPR in their daily practice.

Cost-effectiveness of low-molecular-weight heparin for treatment of pulmonary embolism.

BACKGROUND: Low-molecular-weight heparin (LMWH) appears to be safe and effective for treating pulmonary embolism (PE), but its cost-effectiveness has not been assessed. METHODS: We built a Markov state-transition model to evaluate the medical and economic outcomes of a 6-day course with fixed-dose LMWH or adjusted-dose unfractionated heparin (UFH) in a hypothetical cohort of 60-year-old patients with acute submassive PE. Probabilities for clinical outcomes were obtained from a meta-analysis of clinical trials. Cost estimates were derived from Medicare reimbursement data and other sources. The base-case analysis used an inpatient setting, whereas secondary analyses examined early discharge and outpatient treatment with LMWH. Using a societal perspective, strategies were compared based on lifetime costs, quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio. RESULTS: Inpatient treatment costs were higher for LMWH treatment than for UFH (dollar 13,001 vs dollar 12,780), but LMWH yielded a greater number of QALYs than did UFH (7.677 QALYs vs 7.493 QALYs). The incremental costs of dollar 221 and the corresponding incremental effectiveness of 0.184 QALYs resulted in an incremental cost-effectiveness ratio of dollar 1,209/QALY. Our results were highly robust in sensitivity analyses. LMWH became cost-saving if the daily pharmacy costs for LMWH were < dollar 51, if > or = 8% of patients were eligible for early discharge, or if > or = 5% of patients could be treated entirely as outpatients. CONCLUSION: For inpatient treatment of PE, the use of LMWH is cost-effective compared to UFH. Early discharge or outpatient treatment in suitable patients with PE would lead to substantial cost savings.

Postprandial thermogenesis in obese children before and after weight reduction.

The thermic effect of a meal (TEM) was measured in a group of 10 prepubertal obese children before (OB) and after (OA) weight reduction, and in a group of 10 age-matched control children (C) of normal body weight. Following a hypocaloric balanced diet for 6 +/- 1 months, the obese children lost 5.2 +/- 1.3 kg i.e. 11% of their initial body weight. The thermic response to the mixed liquid meal - fed at an energy level corresponding to 30% of the 24 h premeal resting metabolic rate - was found to be significantly lower in OB than in C children (61 +/- 25 kJ.3h-1 vs 79 +/- 21 kJ.3h-1, P less than 0.05), despite their higher test meal energy. After slimming, the TEM of obese children increased towards the controls' values (73 +/- 30 kJ.3h-1). These results support the hypothesis of the existence of a moderate thermogenic defect in some obese children which represents a consequence rather than an aetiological factor of obesity.

Effect of weight loss on resting energy expenditure in obese prepubertal children.

To assess the effect of weight loss on resting metabolic rate (RMR), the energy expenditure of eight obese prepubertal children (age 9 +/- 1 years; weight 48.7 +/- 9.1 kg; BMI 25.3 +/- 3.9) and of 14 age-matched children of normal body weight (age 9 +/- 1 years; weight 28.8 +/- 5.6 kg; BMI 16.5 +/- 1.7) was measured by indirect calorimetry. The obese children were reinvestigated after a mean weight loss of 5.4 +/- 1.2 kg induced by a six-months mixed hypocaloric diet. Before slimming, the obese group showed a higher daily energy intake than the control group (10.40 +/- 3.45 MJ/day vs 7.97 +/- 2.02 MJ/day respectively; P less than 0.05) but a similar value was observed per unit fat-free mass (FFM) (0.315 +/- 0.032 MJ/kgFFM/day vs 0.329 +/- 0.041 MJ/kgFFM/day respectively). The average RMR of the obese children was greater than that of the control group (5217 +/- 531 kJ/day vs 4477 +/- 506 kJ/day) but similar after adjusting for FFM (4728 +/- 3102 kJ/day vs 4899 +/- 3102 kJ/day). Weight loss resulted in a reduction in RMR (5217 +/- 531 kJ/day vs 4874 +/- 820 kJ/day), each kg of weight loss being accompanied by a decrease of RMR of 64 kJ (15.3 kcal) per day. The changes in RMR induced by weight loss paralleled the changes in FFM. No difference was found in average RQ in obese children vs controls (0.85 +/- 0.03 vs 0.87 +/- 0.03 respectively) and in the obese children before and after weight loss (0.87 +/- 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

The costs of crossing paths and switching tasks between audition and vision.

Switching from one functional or cognitive operation to another is thought to rely on executive/control processes. The efficacy of these processes may depend on the extent of overlap between neural circuitry mediating the different tasks; more effective task preparation (and by extension smaller switch costs) is achieved when this overlap is small. We investigated the performance costs associated with switching tasks and/or switching sensory modalities. Participants discriminated either the identity or spatial location of objects that were presented either visually or acoustically. Switch costs between tasks were significantly smaller when the sensory modality of the task switched versus when it repeated. This was the case irrespective of whether the pre-trial cue informed participants only of the upcoming task, but not sensory modality (Experiment 1) or whether the pre-trial cue was informative about both the upcoming task and sensory modality (Experiment 2). In addition, in both experiments switch costs between the senses were positively correlated when the sensory modality of the task repeated across trials and not when it switched. The collective evidence supports the independence of control processes mediating task switching and modality switching and also the hypothesis that switch costs reflect competitive interference between neural circuits.

Physical activity in free-living, overweight white and black women: divergent responses by race to diet-induced weight loss.

BACKGROUND: Black women are at greater risk of obesity than are white women, perhaps because of their lower levels of physical activity. OBJECTIVE: We compared free-living activity energy expenditure (AEE) in sedentary white and black women (in overweight and normal-weight states) and in never-overweight control subjects. DESIGN: Subjects included 46 women (23 white, 23 black) studied while overweight and after reaching a normal weight and 38 female control subjects (23 white, 15 black). Diet, without exercise training, resulted in a mean weight loss of 13 kg and a body mass index (in kg/m(2)) < 25. Body composition, sleeping energy expenditure, free-living total energy expenditure, and the energy cost of activity and aerobic capacity were assessed before and after weight loss under 4-wk, diet-controlled, weight-stable conditions and in the control subjects. AEE was defined as above-sleep energy expenditure. RESULTS: No significant racial differences in body composition, before or after weight loss, were found. After weight loss, AEE and aerobic capacity increased in the white women and decreased in the black women (P < 0.05 and P < 0.02, respectively). After weight loss, but not before, the white women had a significantly higher mean AEE than did the black women (2448 +/- 979 and 1728 +/- 1373 kJ/d, respectively; P < 0.05), approximating AEEs in the white (2314 +/- 1105) and black (2310 +/- 1251) control subjects. CONCLUSIONS: Relative to the responses of the white women to diet-induced weight loss, the black women became less fit and less physically active. Induction of a normal body weight in overweight black women appeared to produce a more obesity-prone state, favoring weight relapse.

Energy expenditure and postprandial thermogenesis in obese women before and after weight loss.

In six young obese women (mean weight 85 +/- 3 kg) with a childhood history of obesity, and in six young nonobese women (mean weight 55 +/- 2 kg), the energy expenditure was measured during 24 h in a respiratory chamber with a maintenance energy intake. The next day, the thermogenic response to a mixed meal was investigated by using an open circuit indirect calorimetry hood system. In addition, five of the same obese women were similarly studied after a mean weight loss of 12.1 kg (14% of initial body weight) consecutive to an 11-wk hypocaloric diet (protein-supplemented modified fast). Expressed in absolute terms, the total 24 h and basal energy expenditures were found to be significantly greater in the obese (2208 +/- 105 and 1661 +/- 56 kcal/24 h, respectively) than in the controls (1746 +/- 61 and 1230 +/- 40 kcal/24 h, respectively). After weight loss, both the total 24-h and the basal energy expenditures were significantly reduced (2009 +/- 99 kcal/24 h and 1423 +/- 43 kcal/24 h respectively), but both values were still greater than that of the control subjects. The thermogenic response to the mixed meal (a liquid diet containing 17, 54, and 29% as protein, carbohydrate, and lipid calories, respectively, and an energy level determined to cover 60% of the basal energy expenditure computed for 24 h) was found to be significantly reduced in the obese as compared to controls (ie, 7.6 +/- 0.4% versus 9.5 +/- 0.4% of the energy content of the load, respectively, p less than 0.025). After weight loss, the postprandial thermogenesis of the obese was still markedly reduced (ie, 6.2 +/- 0.8%). Both before and after weight loss, the relative increase in diurnal urinary norepinephrine excretion was found to be lower in the obese than in controls, when compared to the nocturnal values. These results show that the greater 24 h energy expenditure of obese women is entirely due to their higher basal metabolic rate. The lower thermogenic response to the meal in the obese supports the concept of a thermogenic defect which can favor energy gain; furthermore, the unchanged response after weight loss in the obese suggests that the thermogenic defect may be a cause rather than a consequence of obesity.

Metabolic predictors of obesity. Contribution of resting energy expenditure, thermic effect of food, and fuel utilization to four-year weight gain of post-obese and never-obese women.

This prospective study was designed to identify abnormalities of energy expenditure and fuel utilization which distinguish post-obese women from never-obese controls. 24 moderately obese, postmenopausal, nondiabetic women with a familial predisposition to obesity underwent assessments of body composition, fasting and postprandial energy expenditure, and fuel utilization in the obese state and after weight loss (mean 12.9 kg) to a post-obese, normal-weight state. The post-obese women were compared with 24 never-obese women of comparable age and body composition. Four years later, without intervention, body weight was reassessed in both groups. Results indicated that all parameters measured in the post-obese women were similar to the never-obese controls: mean resting energy expenditure, thermic effect of food, and fasting and postprandial substrate oxidation and insulin-glucose patterns. Four years later, post-obese women regained a mean of 10.9 kg while control subjects remained lean (mean gain 1.7 kg) (P < 0.001 between groups). Neither energy expenditure nor fuel oxidation correlated with 4-yr weight changes, whereas self-reported physical inactivity was associated with greater weight regain. The data suggest that weight gain in obesity-prone women may be due to maladaptive responses to the environment, such as physical inactivity or excess energy intake, rather than to reduced energy requirements.

Common variants near MC4R are associated with fat mass, weight and risk of obesity.

To identify common variants influencing body mass index (BMI), we analyzed genome-wide association data from 16,876 individuals of European descent. After previously reported variants in FTO, the strongest association signal (rs17782313, P = 2.9 x 10(-6)) mapped 188 kb downstream of MC4R (melanocortin-4 receptor), mutations of which are the leading cause of monogenic severe childhood-onset obesity. We confirmed the BMI association in 60,352 adults (per-allele effect = 0.05 Z-score units; P = 2.8 x 10(-15)) and 5,988 children aged 7-11 (0.13 Z-score units; P = 1.5 x 10(-8)). In case-control analyses (n = 10,583), the odds for severe childhood obesity reached 1.30 (P = 8.0 x 10(-11)). Furthermore, we observed overtransmission of the risk allele to obese offspring in 660 families (P (pedigree disequilibrium test average; PDT-avg) = 2.4 x 10(-4)). The SNP location and patterns of phenotypic associations are consistent with effects mediated through altered MC4R function. Our findings establish that common variants near MC4R influence fat mass, weight and obesity risk at the population level and reinforce the need for large-scale data integration to identify variants influencing continuous biomedical traits.

Body fat distribution in white and black women: different patterns of intraabdominal and subcutaneous abdominal adipose tissue utilization with weight loss.

BACKGROUND: Intraabdominal adipose tissue (IAAT) is the body fat depot most strongly related to disease risk. Weight reduction is advocated for overweight people to reduce total body fat and IAAT, although little is known about the effect of weight loss on abdominal fat distribution in different races. OBJECTIVE: We compared the effects of diet-induced weight loss on changes in abdominal fat distribution in white and black women. DESIGN: We studied 23 white and 23 black women, similar in age and body composition, in the overweight state [mean body mass index (BMI; in kg/m(2)): 28.8] and the normal-weight state (mean BMI: 24.0) and 38 never-overweight control women (mean BMI: 23.4). We measured total body fat by using a 4-compartment model, trunk fat by using dual-energy X-ray absorptiometry, and cross-sectional areas of IAAT (at the fourth and fifth lumbar vertebrae) and subcutaneous abdominal adipose tissue (SAAT) by using computed tomography. RESULTS: Weight loss was similar in white and black women (13.1 and 12.6 kg, respectively), as were losses of total fat, trunk fat, and waist circumference. However, white women lost more IAAT (P < 0.001) and less SAAT (P < 0.03) than did black women. Fat patterns regressed toward those of their respective control groups. Changes in waist circumference correlated with changes in IAAT in white women (r = 0.54, P < 0.05) but not in black women (r = 0.19, NS). CONCLUSIONS: Despite comparable decreases in total and trunk fat, white women lost more IAAT and less SAAT than did black women. Waist circumference was not a suitable surrogate marker for tracking changes in the visceral fat compartment in black women.

A multicentre, retrospective case-control study assessing the role of trabecular bone score (TBS) in menopausal Caucasian women with low areal bone mineral density (BMDa): Analysing the odds of vertebral fracture.

INTRODUCTION: The trabecular bone score (TBS) is a new parameter that is determined from grey level analysis of DXA images. It relies on the mean thickness and volume fraction of trabecular bone microarchitecture. This was a preliminary case-control study to evaluate the potential diagnostic value of TBS, both alone and combined with bone mineral density (BMDa), in the assessment of vertebral fracture. METHODS: Out of a subject pool of 441 Caucasian, postmenopausal women between the ages of 50 and 80 years, we identified 42 women with osteoporosis-related vertebral fractures, and compared them with 126 age-matched women without any fractures (1 case: 3 controls). Primary outcomes were BMDa and TBS. Inter-group comparisons were undertaken using Student's t-tests and Wilcoxon signed ranks tests for parametric and non-parametric data, respectively. Odds ratios for vertebral fracture were calculated for each incremental one standard deviation decrease in BMDa and TBS, and areas under the receiver operating curve (AUC) calculated and sensitivity analysis were conducted to compare BMDa alone, TBS alone, and the combination of BMDa and TBS. Subgroup analyses were performed specifically for women with osteopenia, and for women with T-score-defined osteoporosis. RESULTS: Across all subjects (n=42, 126) weight and body mass index were greater and BMDa and TBS both less in women with fractures. The odds of vertebral fracture were 3.20 (95% CI, 2.01-5.08) for each incremental decrease in TBS, 1.95 (1.34-2.84) for BMDa, and 3.62 (2.32-5.65) for BMDa + TBS combined. The AUC was greater for TBS than for BMDa (0.746 vs. 0.662, p=0.011). At iso-specificity (61.9%) or iso-sensitivity (61.9%) for both BMDa and TBS, TBS + BMDa sensitivity or specificity was 19.1% or 16.7% greater than for either BMDa or TBS alone. Among subjects with osteoporosis (n=11, 40) both BMDa (p=0.0008) and TBS (p=0.0001) were lower in subjects with fractures, and both OR and AUC (p=0.013) for BMDa + TBS were greater than for BMDa alone (OR=4.04 [2.35-6.92] vs. 2.43 [1.49-3.95]; AUC=0.835 [0.755-0.897] vs. 0.718 [0.627-0.797], p=0.013). Among subjects with osteopenia, TBS was lower in women with fractures (p=0.0296), but BMDa was not (p=0.75). Similarly, the OR for TBS was statistically greater than 1.00 (2.82, 1.27-6.26), but not for BMDa (1.12, 0.56-2.22), as was the AUC (p=0.035), but there was no statistical difference in specificity (p=0.357) or sensitivity (p=0.678). CONCLUSIONS: The trabecular bone score warrants further study as to whether it has any clinical application in osteoporosis detection and the evaluation of fracture risk.