Assessment of pixel-oriented k-NN machine learning algorithm performance for the interannual remote sensing monitoring of eelgrass beds at the mouth of the Romaine

Eelgrass cover extent is among the most reliable indicators for measuring changes in coastal ecosystems. Eelgrass has colonized the mouth of the Romaine River and has become a part of environmental monitoring there since 2013. The presence of eelgrass in this area is an essential factor for the early detection of changes in the Romaine coastal ecosystem. This will act as a trigger for an appropriate environmental response to preserve ecosystem health. In this paper, a cost- and time-efficient workflow for such spatial monitoring is proposed using a pixel-oriented k-NN algorithm. It can then be applied to multiple modellers to efficiently map the eelgrass cover. Training data were collected to define key variables for segmentation and k-NN classification, providing greater edge detection for the presence of eelgrass. The study highlights that remote sensing and training data must be acquired under similar conditions, replicating methodologies for collecting data on the ground. Similar approaches must be used for the zonal statistic requirements of the monitoring area. This will allow a more accurate and reliable assessment of eelgrass beds over time. An overall accuracy of over 90% was achieved for eelgrass detection for each year of monitoring.

Newfound Coding Potential of Transcripts Unveils Missing Members of Human Protein Communities

Recent proteogenomic approaches have led to the discovery that regions of the transcriptome previously annotated as non-coding regions [i.e., untranslated regions (UTRs), open reading frames overlapping annotated coding sequences in a different reading frame, and non-coding RNAs] frequently encode proteins, termed alternative proteins (altProts). This suggests that previously identified protein-protein interaction (PPI) networks are partially incomplete because altProts are not present in conventional protein databases. Here, we used the proteogenomic resource OpenProt and a combined spectrum- and peptide-centric analysis for the re-analysis of a high-throughput human network proteomics dataset, thereby revealing the presence of 261 altProts in the network. We found 19 genes encoding both an annotated (reference) and an alternative protein interacting with each other. Of the 117 altProts encoded by pseudogenes, 38 are direct interactors of reference proteins encoded by their respective parental genes. Finally, we experimentally validate several interactions involving altProts. These data improve the blueprints of the human PPI network and suggest functional roles for hundreds of altProts.

Corticospinal Responses Following Gait-Specific Training in Stroke Survivors: A Systematic Review

Corticospinal excitability is subject to alterations after stroke. While the reversal of these alterations has been proposed as an underlying mechanism for improved walking capacity after gait-specific training, this has not yet been clearly demonstrated. Therefore, the objective of this review is to evaluate the effect of gait-specific training on corticospinal excitability in stroke survivors. We conducted an electronic database search in four databases (i.e., Medline, Embase, CINAHL and Web of Science) in June 2022. Two authors screened in an independent way all the studies and selected those that investigated the effect of gait-specific training on variables such as motor-evoked potential amplitude, motor threshold, map size, latency, and corticospinal silent period in stroke survivors. Nineteen studies investigating the effect of gait-specific training on corticospinal excitability were included. Some studies showed an increased MEP amplitude (7/16 studies), a decreased latency (5/7studies), a decreased motor threshold (4/8 studies), an increased map size (2/3 studies) and a decreased cortical silent period (1/2 study) after gait-specific training. No change has been reported in terms of short interval intracortical inhibition after training. Five studies did not report any significant effect after gait-specific training on corticospinal excitability. The results of this systematic review suggest that gait-specific training modalities can drive neuroplastic adaptation among stroke survivors. However, given the methodological disparity of the included studies, additional clinical trials of better methodological quality are needed to establish conclusions. The results of this review can therefore be used to develop future studies to better understand the effects of gait-specific training on the central nervous system.

POS0403 RISK FACTORS FOR PROGRESSION OF RHEUMATOID ARTHRITIS-ASSOCIATED INTERSTITIAL LUNG DISEASE: REASSURING IMPACT OF METHOTREXATE

Background:

Factors associated with rheumatoid arthritis-associated interstitial lung disease (RA-ILD) progression and prognosis are not well identified, especially the impact of methotrexate.

Objectives:

Identify risk factors of ILD progression in RA-ILD patients in a longitudinal study.

Methods:

RA patients with ILD confirmed in 2 high resolution computed tomography (HRCT) chest scans spaced at least 6 months apart (T0: date of the first HRCT chest scan describing ILD; Tx: date of the last HRCT chest scan available) were consecutively included in this retrospective multi-centric study from 2010 to 2020. HRCT chest scans were analyzed for each patient at T0 and Tx by 2 independent radiologists to determinate ILD pattern (definite UIP, probable UIP, indeterminate UIP, non-UIP) and progression during the follow-up including variation of the fibrosis score (aggravated or non-aggravated). Characteristics of patients (demographic-clinical-biological findings, respiratory function tests, and treatments exposure) at ILD diagnosis and during the follow-up (T0-Tx) were analyzed as potential determinants of ILD progression through multivariable logistic regression analysis. Overall survival was analyzed using Kaplan-Meier method.

Results:

74 RA-ILD patients were included. During a mean duration between T0-Tx of 2.8 years ± 2.4, 26 patients (35%) had ILD progression. Thirty-three patients (45%) were treated by methotrexate at ILD diagnosis (T0) and 29 of them (39%) continued methotrexate during T0-Tx. Logistic regression in multivariate analysis revealed that a treatment by methotrexate at ILD diagnosis was protective against ILD progression (OR=0.14 [0.04-0.52]; p=0.0031). Non-UIP pattern at ILD diagnosis was also protective against ILD progression (OR=0.09 [0.02-0.36]; p=0.0005). The follow-up for survival analysis was 5.1 years ± 2.9. Thirty-three patients (31%) died, and the 3-year survival rate was 80%. Survival was better for non-aggravated ILD patients (HR=3.5 [1.46-8.4]; p=0.004) and for patients treated by methotrexate during T0-Tx (HR= 0.36 [0.15-0.84]; p=0.018) and worse for definite UIP patterns (HR=2.570 [1.078-6.128]; p=0.0332).

Conclusion:

In RA-ILD patients, non-UIP pattern and methotrexate treatment are associated with better ILD evolution and prognosis.

Disclosure of Interests:

None declared

Physical Activity and Sedentary Behavior of Elderly Populations during Confinement: Results from the FRENCH COVID-19 ONAPS Survey

Introduction: A national confinement was imposed in France in March 2020 during 55 days to prevent the spread of the virus and protect vulnerable people such as older individuals. This study aimed to describe the movement behaviors, and their determinants, of elderly people (≥ 65 years) during the confinement.Methods: An online survey was conducted from April 1^st, 2020 to May 6^th, 2020 by the National Observatory for Physical Activity and Sedentary behaviors. This study compared the level of physical activity (PA), sitting and screen time before and during the confinement and identified the impact of initial PA, sedentary profiles of the participants and housing conditions.Results: 1,178 people were included in this study. Reaching PA recommendations before lock-down was associated with the change in PA level during lock-down (p < .001). Besides, geographic location was associated with the change in PA, sitting time and screen time during lock-down (respectively p = .03, p = .02, p = .02).Conclusion: This study confirm the negative impact of confinement on senior movement behaviors, whether or not they met with public health recommendations prior to the pandemic. The housing conditions of older people must be also taken into future public health policies.

An Examination of Semantic Impairment in Amnestic MCI and AD: What Can We Learn From Verbal Fluency?

Introduction

The Verbal Fluency Test (VF) is commonly used in neuropsychology. Some studies have demonstrated a marked impairment of semantic VF compared to phonemic VF in Alzheimer’s disease (AD). Since amnestic Mild Cognitive Impairment (aMCI) is associated with increased risk of conversion to incident AD, it is relevant to examine whether a similar impairment is observed in this population. The objective of the present empirical study is to compare VF performance of aMCI patients to those of AD and elderly controls matched one-to-one for age and education.

Method

Ninety-six participants divided into three equal groups (N = 32: AD, aMCI and Controls) were included in this study. Participants in each group were, on average, 76 years of age and had 13 years of education. A repeated measures ANOVA with the Group (AD, aMCI, NC) as between-subject factor and the Fluency condition (“P” and “animals”) as within-subject factor was performed. T-tests and simple ANOVAs were also conducted to examine the interaction.

Results

There was a significant interaction between the groups and the verbal fluency condition. In AD, significantly fewer words were produced in both conditions. In contrast, participants with aMCI demonstrated a pattern similar to controls in the phonemic condition, but generated significantly fewer words in the semantic condition.

Conclusion

These results indicate a semantic memory impairment in aMCI revealed by a simple, commonly-used neuropsychological test. Future studies are needed to investigate if semantic fluency deficits can help predict future conversion to AD.

[Transgenerational impact of chemotherapy: Would the father exposure impact the health of future progeny?]

The number of cancer survivors is increasing and their quality of life is becoming a major public health issue. Cancer treatments reduce men's reproductive health by targeting spermatogenesis. Ultimately, DNA, chromatin and the epigenome of spermatozoa can be altered in cancer survivors. Knowing whether the history of cancer and the treatments received can have consequences on the health of their offspring is therefore a fundamental question for these patients. This review gathers the experimental and epidemiological evidences of the effects observed on the direct descendants and on several generations, and draws up the state of knowledge on the mechanisms potentially involved. Experimental data describe inter- and transgenerational effects of paternal exposure depending on the type of treatment, dose and time of exposure. In the human population, the analysis of the effects specifically due to chemotherapy is still limited because they are often combined with irradiation treatments. However, it appears that chemotherapy agents affect the birth rate but do not have a significant impact on the health of the children born. Nevertheless, the demonstration of modifications of the sperm epigenome in cancer survivors, even after a period of remission, as well as changes in the sperm of the progeny in animal models, suggests a possible transgenerational transmission that remains to be studied in the human population.

The impact of goal-oriented task design on neurofeedback learning for brain-computer interface control

Neurofeedback training teaches individuals to modulate brain activity by providing real-time feedback and can be used for brain-computer interface control. The present study aimed to optimize training by maximizing engagement through goal-oriented task design. Participants were shown either a visual display or a robot, where each was manipulated using motor imagery (MI)-related electroencephalography signals. Those with the robot were instructed to quickly navigate grid spaces, as the potential for goal-oriented design to strengthen learning was central to our investigation. Both groups were hypothesized to show increased magnitude of these signals across 10 sessions, with the greatest gains being seen in those navigating the robot due to increased engagement. Participants demonstrated the predicted increase in magnitude, with no differentiation between hemispheres. Participants navigating the robot showed stronger left-hand MI increases than those with the computer display. This is likely due to success being reliant on maintaining strong MI-related signals. While older participants showed stronger signals in early sessions, this trend later reversed, suggesting greater natural proficiency but reduced flexibility. These results demonstrate capacity for modulating neurofeedback using MI over a series of training sessions, using tasks of varied design. Importantly, the more goal-oriented robot control task resulted in greater improvements.

Tackling obesity at the community level by integrating healthy diet, movement and non-movement behaviours

The increase in obesity prevalence over the last decades has generally been attributed to suboptimal macronutrient diet composition and insufficient physical activities. However, recent literature has revealed that other environmental factors contribute to the positive energy balance that underlies body-weight gain and should be considered in efforts to tackle obesity. As discussed in this paper, it also appears that successful obesity management could not happen without actions at a community level that would ultimately impact energy balance. These measures generally include a better use of the school environment to promote healthy behaviours. Furthermore, in a foreseeable future, communities will probably have to consider sustainable development in their list of criteria deserving attention in the global management of obesity.

The expression of NTPDase1 and -2 of Leishmania infantum chagasi in bacterial and mammalian cells: Comparative expression, refolding and nucleotidase characterization

Visceral Leishmaniasis (VL) represents an important global health problem in several warm countries around the world. The main targets in this study are the two nucleoside triphosphate diphosphohydrolases (NTPDases) from Leishmania infantum chagasi that are the main etiologic agent of VL in the New World. These enzymes, called LicNTPDase1 and -2, are homologous to members 5 and 6 of the mammalian E-NTPDase/CD39 superfamily of enzymes. These enzymes hydrolyze nucleotides and accordingly can participate in the purine salvage pathways and in the modulation of purinergic signaling through the extracellular nucleotide-dependent host immune responses. They can therefore affect adhesion and infection of host cells and the parasite virulence. To further characterize these enzymes, in this work, we expressed LicNTPDase1 and -2 in the classical bacterial system Escherichia coli and mammalian cell system COS-7 cells. Our data demonstrate that changes in refolding after expression in bacteria can increase the activity of recombinant (r) rLicNTPDase2 up to 20 times but has no significant effect on rLicNTPDase1. Meanwhile, the expression in COS-7 led to a significant increase in activity for rLicNTPDase1.

Adaptations to a diet-based weight-reducing programme in obese women resistant to weight loss

The aim of this study was to assess energy intake, resting metabolic rate (RMR), appetite sensations, eating behaviours and sleep duration and quality in obese women resistant to body weight loss when subjected to a diet-based weight-reducing programme. A pooled cohort of obese women (n = 75; aged 39 ± 8 years; body mass index: 33 ± 4 kg m(-2)) participated in a 12-16-week diet-based weight loss programme targeting a daily energy deficit of 500-700 kcal d(-1). Women were classified in tertiles a posteriori based on the response of their body weight to dietary supervision (high, moderate and low responders). Post-intervention, mean weight loss was 3.3 ± 2.8 kg and explained by the 2.9 ± 2.6 kg reduction in fat mass. Mean weight loss was 6.2 ± 1.6, 3.4 ± 0.6 and 0.2 ± 1.4 kg in participants classified in the high, middle and low tertiles, respectively. Women in the low tertile reduced their daily energy intake and susceptibility to hunger during the programme to a lesser extent than those in the high tertile and had higher fasting hunger in response to the dietary intervention. Women in the high tertile maintained their RMR, which was in contrast to the significant decrease predicted by their weight loss. They also reported a significant improvement in sleep quality and an increase in sleep duration compared with other tertiles. The differences in the response of body weight to dietary supervision may be explained, in part, by variations in energy intake, eating behaviours, appetite sensations and sleep duration and quality.

Exercise and negative energy balance in males who perform mental work

BACKGROUND

Although energy expenditure during mental work is not higher than energy expenditure at rest, a stressful mental task is related to an increase in energy intake. It is suggested that mental work produces physiological changes, thereby influencing food intake.

OBJECTIVE

Because physical activity can influence hunger, the aim of the study was to determine if the introduction of an active pause could counteract the negative effects of mental work on energy intake and energy balance.

METHOD

Twelve male students, of normal weight, between 15 and 20 years old were evaluated. All subjects participated in three different sessions realized in a randomized order: (i) without pause = relaxation/mental work/meal; (ii) relaxation pause = mental work/relaxation/meal; and (iii) exercise pause = mental work/exercise/meal. Energy expenditure was measured with indirect calorimetry, energy intake was measured with a cold buffet-type meal of 40 items, and appetite-related sensations were measured with visual analogue scales. The effect of introducing an active pause in energy intake and energy balance was studied.

RESULTS

The introduction of an active pause did not influence energy intake; although, higher appetite-related sensations were observed (16-26 mm on a 150-mm scale; P < 0.05). After accounting for the energy expenditure related to physical activity, a lower energy balance was measured for the exercise pause visit compared with the visit without a pause (-1137 kJ; P < 0.05).

CONCLUSION

This study indicates that being active between mental work and a meal could represent a strategy to create a negative energy balance following mental work via an increased energy expenditure and a maintenance of energy intake. Globally, these results could help individuals attain and/or maintain a healthy body weight in a context where mental work is omnipresent.

Insulin secretion and its association with physical activity, fitness and screen time in children

OBJECTIVES

To determine the independent associations of moderate to vigorous physical activity (MVPA), fitness, screen time, and adiposity with insulin secretion in children.

DESIGN AND METHODS

Caucasian youth (n = 423/630), 8-10 years old, with at least one obese biological parent, were studied (QUALITY cohort). Insulin secretion was measured using HOMA2-%B, area under the curve (AUC) of insulin to glucose over the first 30 minutes (AUC I/G(t30min)) of the OGTT and AUC I/G(t120min) over 2 hours. Fitness was measured by VO₂peak ; percent fat mass (PFM) by DXA; 7-day MVPA by accelerometry; self-reported screen time included television, video game, or computer use. Models were adjusted for age, sex, season, puberty, PFM, and insulin sensitivity [IS] (HOMA2-IS, Matsuda-ISI).

RESULTS

PFM was strongly associated with insulin secretion, even after adjustment for IS: for every 1% increase in PFM, insulin secretion increased from 0.3% to 0.8% across indices. MVPA was negatively associated with HOMA2-%B (P < 0.05), but not with OGTT-derived measures. Fitness was negatively associated with AUC I/G(t120min) (P < 0.05). Screen time showed a trend toward higher HOMA2-%B in girls (P = 0.060).

CONCLUSIONS

In children with an obese parent, lower insulin secretion is associated with lower adiposity, higher MVPA, better fitness, and possibly reduced screen time.

Maternal fitness at the onset of the second trimester of pregnancy: correlates and relationship with infant birth weight

What is already known about this subject A healthy life begins in utero and a healthy pregnancy requires a fit and healthy mother. Physical activity during pregnancy provides a stimulation that is essential for promoting optimal body oxygenation and composition as well as metabolic fitness during pregnancy. Although a higher maternal fitness is expected to provide a beneficial fetal environment, it is still unclear whether physical fitness during pregnancy contributes to perinatal health. What this study adds Participation in sports and exercise previously and at the beginning of pregnancy can benefit maternal health by improving cardiorespiratory fitness during pregnancy, irrespective of maternal body mass index. Maternal strength, an indicator of muscular fitness, is an independent determinant of infant fetal growth and can positively influence birth weight.

BACKGROUND

It is still unclear whether maternal physical activity and fitness during pregnancy contributes to perinatal health.

OBJECTIVES

The aims of this study were to characterize maternal physical fitness at 16 weeks of pregnancy and to examine its effects on infant birth weight.

METHODS

Maternal anthropometry (body mass index [BMI] and skin-folds), physical activity, cardiorespiratory fitness (VO2 peak) and muscular fitness (handgrip strength) were assessed at 16 weeks of gestation in 65 healthy pregnant women. Offspring birth weight was collected from maternal charts after delivery.

RESULTS

A higher VO2 peak was associated with physical activity spent at sports and exercise before and in early pregnancy (P = 0.0005). Maternal BMI was negatively associated with cardiorespiratory fitness (P < 0.0001) but positively related to muscular strength (P = 0.0001). Unlike maternal cardiorespiratory fitness, handgrip strength was positively associated with infant birth weight (r = 0.34, P = 0.0068) even after adjustment for confounders (adjusted r = 0.27, P = 0.0480).

CONCLUSION

A positive relationship between maternal muscular fitness and infant birth weight highlighted maternal strength in pregnancy as a new determinant of infant birth weight.

Adiposity and glucose intolerance exacerbate components of metabolic syndrome in children consuming sugar-sweetened beverages: QUALITY cohort study

BACKGROUND

Sugar-sweetened beverage (SSB) consumption is linked to weight gain and metabolic syndrome (MetS) components in children, but whether these associations are modified by excess weight and glucose tolerance status in children is not known.

OBJECTIVE

The objective of this study was to examine the cross-sectional associations between SSB intake and MetS components among children above and below the 85th body mass index (BMI) percentile and those with and without impaired glucose tolerance (IGT).

METHODS

Data were from the QUébec Adiposity and Lifestyle InvesTigation in Youth study (2005-2008). Caucasian children aged 8-10 years (n = 632) were recruited from 1040 primary schools in Québec, Canada. SSB consumption was assessed by three 24-h dietary recalls, body fat mass by dual-energy absorptiometry, physical activity by 7-d accelerometer. Multivariate linear regressions were used, with age, sex, fat mass index and physical activity as covariates, including waist circumference (WC), systolic blood pressure (SBP), concentrations of triglyceride and high-density lipoprotein cholesterol and homeostasis model assessment of insulin resistance (HOMA-IR) as outcome variables.

RESULTS

Among overweight children, a 100-mL higher SSB consumption was associated with a 0.1-unit higher HOMA-IR (P = 0.009) and a 1.1-mm Hg higher SBP (P = 0.001). In children with IGT, a 100-mL higher SSB consumption was associated with a 1.4-mm Hg higher SBP and a 4.0-cm higher WC (P < 0.001). These associations were not observed among children <85th BMI percentile.

CONCLUSIONS

Our results suggest that the association between higher SSB consumption and MetS components is more evident in overweight/obese and glucose-intolerant children.

Non Linear Weight Gain with Long Term Overfeeding in Man

This study deals with the pattern of body weight gain during an overfeeding period with a constant energy intake, in order to assess whether total daily energy expenditure (TEE) increased with body weight and thus could account for the progressive slow down in body weight gain over time. Twenty-four young adult males (12 pairs of identical twins) were overfed by 4.2 MJ per day, six days a week, for a total of 84 days during a 100-day overfeeding period. The total excess amount each man consumed was 353 MJ. It was assumed that, at a given time, the TEE increase (E) was dependent on body weight gain and energy cost (C) was proportional to the daily body weight gain. Results show an exponential increase in body weight, fat free mass, and fat mass (with half-times of 86, 57, and 84 days, respectively) that allows the calculation of E (246 +/- 37 kJ x kg(-1) x d(-1), mean +/- SE) and C (32.3 +/- 2.4 MJ x kg(-1)). Energy expenditure from other sources besides resting metabolic rate, such as physical activity and thermic effect of food, may represent as much as 65% of E. At the beginning of the overfeeding period, almost all the energy surplus was recovered as body substances but this proportion decreased to 60% after 100 days of overfeeding. It is concluded that 1) TEE changes were related to body weight change, 2) about 65% of E were accounted for by physical activity, thermic effect of food, or some other components, and 3) the fraction of the energy surplus stored as body substances decreased with the duration of overfeeding.

Exercise and Obesity

This paper reviews succinctly the evidence for a role of regular exercise in the prevention and the treatment of obesity and of its metabolic complications. Seventeen propositions relevant to an understanding of the topic are considered. The evidence suggests that regular exercise can be an important factor in the development of sustained negative energy balance conditions provided the volume of activity is high. This implies a program of low to moderate intensity exercise performed on an almost daily basis for at least one hour per session. To induce significant weight and fat losses and to treat overweight and obese patients, compliance to the program for several years becomes a necessity. Exercise increases lipid substrate oxidation and may favor carbohydrate intake for the same amount of energy intake. The acute effects of exercise on resting metabolic rate are well documented, but the long-term influences of exercise training seem to be small and are rapidly suppressed with the cessation of training. The obese benefits also from a regular exercise regimen in terms of improved insulin sensitivity, lipid and lipoprotein profile, and blood pressure, as well as reduced risk of death. Regular exercise, such as walking, is a healthy course of action for the overweight or the obese patients.

Obesity: a disease or a biological adaptation? An update

Obesity is characterized by the accumulation of excess body fat and can be conceptualized as the physical manifestation of chronic energy excess. An important challenge of today's world is that our so-called obesogenic environment is conducive to the consumption of energy and unfavourable to the expenditure of energy. The modern, computer-dependent, sleep-deprived, physically inactive humans live chronically stressed in a society of food abundance. From a physiological standpoint, the excess weight gain observed in prone individuals is perceived as a normal consequence to a changed environment rather than a pathological process. In other words, weight gain is a sign of our contemporary way of living or a 'collateral damage' in the physiological struggle against modernity. Additionally, substantial body fat loss can complicate appetite control, decrease energy expenditure to a greater extent than predicted, increase the proneness to hypoglycaemia and its related risk towards depressive symptoms, increase the plasma and tissue levels of persistent organic pollutants that promote hormone disruption and metabolic complications, all of which are adaptations that can increase the risk of weight regain. In contrast, body fat gain generally provides the opposite adaptations, emphasizing that obesity may realistically be perceived as an a priori biological adaptation for most individuals. Accordingly, prevention and treatment strategies for obesity should ideally target the main drivers or root causes of body fat gain in order to be able to improve the health of the population.

Physical activity vs. sedentary time: independent associations with adiposity in children

OBJECTIVE

To investigate the independent associations between objectively measured levels of movement intensity (i.e., time spent sedentary and at light, moderate and vigorous intensities) and indicators of adiposity in a cohort of Canadian children.

METHODS

A cross-sectional study was conducted in 550 Caucasian children aged 8-10 years with at least one obese biological parent. Physical activity and sedentary time (accelerometer over 7 d) and indicators of adiposity (% body fat measured by dual-energy X-ray absorptiometry and waist-to-height ratio) were objectively measured. We examined the associations between levels of movement intensity and adiposity in multi-level linear regression models adjusted for age, sex, sleep duration, energy intake, sexual maturation, parental socioeconomic status and parental body mass index.

RESULTS

Objectively measured sedentary time was not associated with adiposity indicators in this cohort (unadjusted and adjusted models). However, moderate-to-vigorous physical activity (MVPA) was inversely associated with % body fat (adj. β = -0.047; P = 0.02) and waist-to-height ratio (adj. β = -0.071; P < 0.001), independent of sedentary time and other covariates. Additionally, we observed that children who did not accumulate ≥60 min d(-1) of MVPA were more likely to be overweight or obese compared to those who met the recommendation (odds ratio [OR] 2.22, 95% confidence interval [CI] 1.45-3.38). In contrast, there was no difference in the likelihood of being categorized as overweight or obese between those who met the recommendation of ≤2 h d(-1) of screen time and those who did not meet this recommendation (OR 1.27, 95% CI 0.75-2.01).

CONCLUSION

The present study suggests that MVPA is independently associated with adiposity indices in this sample of children while sedentary time is not. Future studies should examine the best approach to increase MVPA in children and youth.

Effect of proteins from different sources on body composition

High-protein diets have beneficial effects on body fat regulation, but the difference in effect of various types of protein is not known. Thus, this review examines whether proteins from different sources have similar effects on body composition and energy balance. Animal proteins, especially those from dairy, seem to support better muscle protein synthesis than plant proteins. This could potentially enhance energy expenditure, but no conclusion can be drawn from the scant evidence. Some studies, but not all, demonstrate the higher satiating effect of whey and fish proteins than other protein sources. The evidence from intervention studies comparing the effects of different protein sources on body weight is inconclusive. However, body composition was not evaluated precisely in these studies and the literature is still incomplete (e.g. comparative data are missing for legumes and nuts). Protein intake enhances energy expenditure, satiety and fat loss, but there is no clear evidence to indicate whether there is a difference in the effect dependent on the source of the protein, i.e. from animal or plant-based foods.

Short sleep duration preferentially increases abdominal adiposity in adults: preliminary evidence

What is already known about this subject •  The evidence that short sleep duration is another determinant of obesity is accumulating. •  Lack of sleep has been reported to constitute a metabolic stressor, with increased cortisol concentrations as the end product. What this study adds •  This is the first study to show that short sleep duration is associated with a preferential increase in abdominal adiposity in adults.

SUMMARY

The aim of this 6-year longitudinal study was to verify whether short sleep duration preferentially increases abdominal adiposity in adults. A total of 276 adults, aged 18-64 years, from the Quebec Family Study were available for this study. Anthropometric measurements (body mass index and waist circumference), self-reported sleep duration and several covariates were assessed. A regression equation derived from the changes in body mass index and waist circumference of normal- and long-duration sleepers (reference category, ≥ 7 h of sleep per night, n = 233) was used to predict the change in waist circumference of short-duration sleepers (≤6 h of sleep per night, n = 43). Additionally, the influence of sleep duration on waist circumference changes was modelled by using linear regression in both sleep duration groups, adjusting for changes in body mass index and other covariates. We observed that measured (actual) changes in waist circumference were significantly greater than predicted changes (mean ± SEM: 3.41 ± 0.53 vs. 2.69 ± 0.51 cm, respectively, P < 0.05), implying that short-duration sleepers had an excess of abdominal fat accumulation over the 6-year follow-up period. After controlling for the changes in total adiposity as measured by body mass index, only short-duration sleepers gained more abdominal adiposity over 6 years. The present study provides evidence that short sleep duration is associated with preferential increases in abdominal adiposity in adults. This finding is of particular concern because abdominal adiposity is correlated with a number of metabolic anomalies.

The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis

Different outcomes of the effect of catechin-caffeine mixtures and caffeine-only supplementation on energy expenditure and fat oxidation have been reported in short-term studies. Therefore, a meta-analysis was conducted to elucidate whether catechin-caffeine mixtures and caffeine-only supplementation indeed increase thermogenesis and fat oxidation. First, English-language studies measuring daily energy expenditure and fat oxidation by means of respiration chambers after catechin-caffeine mixtures and caffeine-only supplementation were identified through PubMed. Six articles encompassing a total of 18 different conditions fitted the inclusion criteria. Second, results were aggregated using random/mixed-effects models and expressed in terms of the mean difference in 24 h energy expenditure and fat oxidation between the treatment and placebo conditions. Finally, the influence of moderators such as BMI and dosage on the results was examined as well. The catechin-caffeine mixtures and caffeine-only supplementation increased energy expenditure significantly over 24 h (428.0 kJ (4.7%); P < 0.001 and 429.1 kJ (4.8%); P < 0.001, respectively). However, 24 h fat oxidation was only increased by catechin-caffeine mixtures (12.2 g (16.0%); P < 0.02 and 9.5 g (12.4%); P = 0.11, respectively). A dose-response effect on 24 h energy expenditure and fat oxidation occurred with a mean increase of 0.53 kJ mg(-1) (P < 0.01) and 0.02 g mg(-1) (P < 0.05) for catechin-caffeine mixtures and 0.44 kJ mg(-1) (P < 0.001) and 0.01 g mg(-1) (P < 0.05) for caffeine-only. In conclusion, catechin-caffeine mixtures or a caffeine-only supplementation stimulates daily energy expenditure dose-dependently by 0.4-0.5 kJ mg(-1) administered. Compared with placebo, daily fat-oxidation was only significantly increased after catechin-caffeine mixtures ingestion.

Globalization and modernization: an obesogenic combination

Animal research has well established that a link exists between variations in corticosteroids and the proneness to excess body fat accumulation. Accordingly, it is known that adrenalectomy is an efficient approach to counteract weight gain in most animal models of obesity. In humans, the association between variations in corticosteroids, its stress-related environmental effects and the predisposition to obesity is more difficult to demonstrate. In this paper, we propose that this relationship is accentuated by globalization and modernization which favour a labour context imposing additional stress and changes in life habits promoting a positive energy balance. Our main hypothesis is that the increase in knowledge-based work, and the decrease of quality and duration of sleep both induce an increase in cortisolaemia and glycaemia instability, which results in an increase in food intake, a reduction in energy expenditure and body fat gain. The authors of this paper believe that, from a socioeconomic perspective, globalization leads every nation of the world in conflict with itself and may consequently represent a real problem. On one hand, there are preoccupations related to productivity and money making. On the other hand, people have to adopt a daily lifestyle leading to hyperphagia and decreased energy expenditure in order to maintain their economic competitiveness.

Couple dissatisfaction and eating profile: a mediation effect of coping style

Individuals' ways of coping with psychological stress have often been associated with body weight regulation through their impact on eating behaviours. In particular, emotion-oriented and distraction-oriented coping styles have been steadily related to disordered eating. Couple dissatisfaction may be experienced as an important psychological stressor and could therefore affect eating behaviours through the use of inadequate coping strategies. The study proposes 1) to compare women reporting a low vs a high level of couple satisfaction, and 2) to test mediational models including couple satisfaction, coping styles, and eating variables. Analyses were performed among 65 overweight/obese premenopausal women who reported being weight-preoccupied. Women exhibiting couple dissatisfaction (34.8%) showed a higher level of EDE-Q restraint, more intense concerns about eating and shape, a higher level of disinhibition and susceptibility to hunger and endorsed more often a distraction-oriented coping style, independently of their body weight. Furthermore, distraction- oriented coping style seemed to be a valid mediator of the relation between couple dissatisfaction and eating behaviours. Since non-normative eating behaviours, namely disinhibition and susceptibility to hunger, have been particularly linked to a higher body weight status, it is relevant to extend the scope of interest to more distal contributing factors, such as couple dissatisfaction.

Effect of calcium from dairy and dietary supplements on faecal fat excretion: a meta-analysis of randomized controlled trials

Observational studies have found that dietary calcium intake is inversely related to body weight and body fat mass. One explanatory mechanism is that dietary calcium increases faecal fat excretion. To examine the effect of calcium from dietary supplements or dairy products on quantitative faecal fat excretion, we performed a systematic review with meta-analysis. We included randomized, controlled trials of calcium (supplements or dairy) in healthy subjects, where faecal fat excretion was measured. Meta-analyses used random-effects models with changes in faecal fat excreted expressed as standardized mean differences, as the studies assessed the same outcome but measured in different ways. An increased calcium intake resulted in increased excretion of faecal fat by a standardized mean difference of 0.99 (95% confidence intervals: 0.63-1.34; P < 0.0001; expected to correspond to approximately 2g day(-1)) with moderate heterogeneity (I(2) = 49.5%) indicating some inconsistency in trial outcomes. However, the dairy trials showed homogeneous outcomes (I(2)=0%) indicating consistency among these trials. We estimated that increasing the dairy calcium intake by 1241 mg day(-1) resulted in an increase in faecal fat of 5.2 (1.6-8.8) g day(-1). In conclusion, dietary calcium has the potential to increase faecal fat excretion to an extent that could be relevant for prevention of weight (re-)gain. Long-term studies are required to establish its potential contribution.

Physical training and changes in regional adipose tissue distribution

Obesity has been associated with numerous metabolic complications, such as changes in the concentration and/or composition of plasma lipoproteins, glucose intolerance and hyperinsulinemia leading to diabetes and hypertension. The relation of obesity to cardiovascular disease has not, however, been consistently reported. Recent prospective studies have clearly indicated that the distribution of adipose tissue was a significant cardiovascular risk factor and numerous studies have shown that metabolic disturbances were more closely associated with the level of abdominal fat than excess adiposity per se. As obese men generally store their energy excess in the abdominal region and women in the peripheral fat depots, the metabolic complications of obesity seem to be more closely related to adiposity in men than in women. It is suggested that the sex dimorphism observed in adipose tissue localization could partly explain the greater cardiovascular risk associated with obesity in men than in women. Indeed, obese women with a "male" (abdominal) distribution of body fat have greater metabolic complications than women with lower body fat. When aerobic exercise-training is used to induce weight loss, men generally lose more fat than women. In men, the loss of adipose tissue appears to be central, potentially reducing the risk of cardiovascular disease, whereas a relative resistance to fat loss is observed in women compared to men. Although resistance to fat loss is noted in women, those with a "male" distribution of adipose tissue (high waist-to-hip ratio and high intra-abdominal fat deposition) and with associated metabolic complications greatly benefit from aerobic exercise-training.(ABSTRACT TRUNCATED AT 250 WORDS)