Edmonton Obesity Staging System for Pediatrics, quality of life and fitness in adolescents with obesity.

BACKGROUND: Body mass index (BMI) is often used to diagnose obesity in childhood and adolescence but has limitations as an index of obesity-related morbidity. The Edmonton Obesity Staging System for Pediatrics (EOSS-P) is a clinical staging system that uses weight-related comorbidities to determine health risk in paediatric populations. The purpose of this study was to investigate the associations of EOSS-P and BMI percentile with quality of life (QOL), cardiorespiratory fitness (CRF) and muscular strength in adolescents with obesity. METHODS: Participants were enrolled at baseline in the Healthy Eating, Aerobic and Resistance Training in Youth trial (BMI = 34.6 ± 4.5 kg m-2, age = 15.6 ± 1.4 years, N = 299). QOL, CRF (peak oxygen uptake, VO2peak) and muscular strength were assessed by the Pediatric QOL Inventory (PedsQL), indirect calorimetry during a maximal treadmill test and eight-repetition maximum bench and leg press tests, respectively. Participants were staged from 0 to 3 (absent to severe health risk) according to EOSS-P. Associations were assessed using age-adjusted and sex-adjusted general linear models. RESULTS: Quality of life decreased with increasing EOSS-P stages (p < 0.001). QOL was 75.7 ± 11.4 in stage 0/1, 69.1 ± 13.1 in stage 2 and 55.4 ± 13.0 in stage 3. BMI percentile was associated with VO2peak (ß = -0.044 mlO2 kg-1 min-1 per unit increase in BMI percentile, p < 0.001), bench press (ß = 0.832 kg per unit increase in BMI percentile, p = 0.029) and leg press (ß = 3.992 kg, p = 0.003). There were no significant differences in treadmill time or VO2peak between EOSS-P stages (p > 0.05). CONCLUSION: As EOSS-P stages increase, QOL decreases. BMI percentile was negatively associated with CRF and positively associated with muscular strength.

Understanding low adherence to an exercise program for adolescents with obesity: the HEARTY trial.

INTRODUCTION: Despite efforts to improve adherence to physical activity interventions in youth with obesity, low adherence and attrition remain areas of great concern. OBJECTIVE: The study was designed to determine which physiological and/or psychological factors predicted low adherence in adolescents with obesity enrolled in a 6-month exercise intervention study aimed to improve body composition. METHODS: Three hundred four adolescents with obesity aged 14-18 years who volunteered for the HEARTY (Healthy Eating Aerobic and Resistance Training in Youth) randomized controlled trial completed physiological (body mass index, waist circumference, per cent body fat, resting metabolic rate and aerobic fitness) and psychological (body image, mood, self-esteem and self-efficacy) measures. RESULTS: One hundred forty-one out of 228 (62%) randomized to exercise groups had low adherence (completed <70% of the prescribed four exercise sessions per week) to the intervention protocol. Logistic regression revealed that there were no baseline demographic or physiological variables that predicted low adherence in the participants. Appearance concern (a subscale of body image) (odds ratio [OR] 1.46, 95% confidence interval [CI]: 1.01, 2.1, P = 0.04), depressive mood (OR 1.12, 95% CI: 1.01, 1.23, P = 0.03) and confused mood (OR 1.16, 95% CI: 1.05, 1.27, P = 0.003) (two subscales of mood) were significant predictors of low adherence. CONCLUSIONS: Adolescents with obesity who had higher appearance concerns and depressive and confused moods were less likely to adhere to exercise. Body image and mood should be screened to identify adolescents who may be at high risk of poor adherence and who may need concurrent or treatment support to address these psychological issues to derive maximal health benefits from an exercise programme.

Vasomotor symptoms and cardiometabolic risk factors in menopausal women: a MONET Group study.

INTRODUCTION: Conflicting results have been reported concerning the prevalence of cardiometabolic risk factors in women experiencing vasomotor symptoms (VMS). OBJECTIVES: To compare cardiometabolic risk factors between women with and without VMS during the menopause transition and to determine the influence of physical activity on the prevalence of VMS. METHODS: Yearly assessment of women transitioning through menopause included self-reported VMS (hot flushes and night sweats), body composition and fat distribution, fasting glucose, insulin and lipids, and physical activity levels. RESULTS: Eighty-five of the 102 premenopausal women at baseline were included (age: 49.9 ± 2.0 years; body mass index: 23.2 ± 2.2 kg/m(2)). According to linear mixed model analyses, no statistically significant differences were observed for fat mass, lean body mass, body fat distribution indices and cardiometabolic risk factors, when comparing symptomatic vs. asymptomatic women. Neither physical activity levels nor intensity were associated with the prevalence of VMS. CONCLUSION: Our results suggest that women transitioning through menopause who reported VMS did not show greater deteriorations in body composition, body fat distribution and cardiometabolic risk factors. Furthermore, physical activity levels were not associated with lower prevalence of vasomotor symptoms in the present cohort.

Prevalence of metabolic syndrome and its risk factors in Canadian children and adolescents: Canadian Health Measures Survey Cycle 1 (2007-2009) and Cycle 2 (2009-2011).

INTRODUCTION: We investigated the prevalence of metabolic syndrome (MetS) and its risk factors, and the influence of socioeconomic status, in Canadian children and adolescents. METHODS: Canadian Health Measures Survey cycle 1 (2007-2009) and cycle 2 (2009-2011) respondents aged 10 to 18 years who provided fasting blood samples were included (n = 1228). The International Diabetes Federation (IDF) consensus definition for children and adolescents (10-15 years) and worldwide adult definition (≥ 16 years) were used to diagnose MetS. Prevalence of MetS and its risk factors were calculated and differences by socioeconomic status were examined using χ2 tests. RESULTS: The prevalence of MetS was 2.1%. One-third (37.7%) of participants had at least one risk factor, with the most prevalent being abdominal obesity (21.6%), low HDL-C (19.1%) and elevated triglyceride levels (7.9%). This combination of abdominal obesity, low HDL-C and elevated triglyceride levels accounted for 61.5% of MetS cases. Participants from households with the highest income adequacy and educational attainment levels had the lowest prevalence of one or more MetS risk factors, abdominal obesity and low HDL-C. CONCLUSION: The prevalence of MetS (2.1%) was lower than previously reported in Canada (3.5%) and the USA (4.2%¬-9.2%), potentially due to the strict application of the IDF criteria for studying MetS. One-third of Canadian children and adolescents have at least one risk factor for MetS. Given that the risk for MetS increases with age, these prevalence estimates, coupled with a national obesity prevalence of almost 10% among youth, point to a growing risk of MetS and other chronic diseases for Canadian youth.

TITRE: Prévalence du syndrome métabolique et de ses facteurs de risque chez les enfants et les adolescents canadiens : Enquête canadienne sur les mesures de la santé, cycle 1 (2007-2009) et cycle 2 (2009-2011). INTRODUCTION: Nous avons étudié la prévalence du syndrome métabolique (SMet) et de ses facteurs de risque ainsi que l'influence du statut socioéconomique chez les enfants et les adolescents canadiens. MÉTHODOLOGIE: Nous avons inclus dans notre étude les 1228 répondants de l'Enquête canadienne sur les mesures de la santé, cycle 1 (2007-2009) et cycle 2 (2009-2011), âgés de 10 à 18 ans et ayant fourni un échantillon de sang à jeun. Nous avons utilisé les définitions consensuelles du SMet proposées par la Fédération internationale du diabète (FID) pour les enfants et adolescents (10 à 15 ans) et pour les adultes (16 ans et plus). Nous avons mesuré la prévalence du SMet et de ses facteurs de risque ainsi que les différences en fonction du statut socioéconomique au moyen de tests du χ2. RÉSULTATS: La prévalence du SMet était de 2,1 %. Le tiers (37,7 %) des répondants présentaient au moins un facteur de risque, les plus répandus étant l'obésité abdominale (21,6 %), un faible taux de C-HDL (19,1 %) et un taux de triglycérides élevé (7,9 %). Cette combinaison d'obésité abdominale, de faible taux de C-HDL et de taux élevé de triglycérides correspondait à 61,5 % des cas de SMet. Les participants des ménages de la tranche supérieure de revenu et bénéficiant d'un niveau de scolarité élevé présentaient la plus faible prévalence d'un ou de plusieurs facteurs de risque du SMet, d'obésité abdominale et de faible taux de C-HDL. CONCLUSION : La prévalence du SMet (2,1 %) s'est révélée inférieure à celle mesurée auparavant pour le Canada (3,5 %) et les États-Unis (4,2 % à 9,2 %), sans doute en raison de l'application stricte des critères de la FID pour l'étude du SMet. Le tiers des enfants et des adolescents canadiens présentaient au moins un facteur de risque de SMet. Comme le risque de SMet augmente avec l'âge, ces estimations de la prévalence, couplées à une prévalence nationale de l'obésité d'environ 10 % chez les jeunes, laissent entrevoir un accroissement du risque de SMet et d'autres maladies chroniques chez les jeunes Canadiens.

Effects of aerobic and resistance training on abdominal fat, apolipoproteins and high-sensitivity C-reactive protein in adolescents with obesity: the HEARTY randomized clinical trial.

OBJECTIVES: To investigate the effects of aerobic training, resistance training, or both on abdominal subcutaneous fat (subcutaneous adipose tissue (SAT)) (deep and superficial), visceral fat (visceral adipose tissue (VAT)), apolipoproteins A-1 and B (ApoA-1, ApoB), ApoB/ApoA-1 ratio and high-sensitivity C-reactive protein (HSCRP) in post-pubertal adolescents with obesity. PARTICIPANTS: After a 4-week supervised moderate-intensity exercise run-in period, 304 postpubertal adolescents with overweight (body mass index (BMI) ⩾85th percentile for age and sex+diabetes risk factor) or obesity (⩾95th BMI percentile) aged 14-18 years were randomized to four groups for 22 weeks (5 months): aerobic training, resistance training, combined training or a non-exercising control. METHODS: This study used a randomized controlled design. All groups received dietary counseling designed to promote healthy eating with a maximum daily energy deficit of 250 kcal. Abdominal fat (SAT and VAT) at the level of the fourth and fifth lumbar vertebrae (L4-L5) was measured by magnetic resonance imaging and ApoA-1, ApoB and HSCRP were measured after a 12-h fast at baseline and after 6 months. RESULTS: Changes in SAT at L4-L5 were -16.2 cm(2) in aerobic (P=0.04 vs control), -22.7 cm(2) in resistance (P=0.009 vs control) and -18.7 cm(2) in combined (P=0.02 vs control). Combined training reduced ApoB levels from 0.81±0.02 to 0.78±0.02 g l(-1) (P=0.04 vs control) and ApoB/ApoA-1 ratio from 0.67±0.02 to 0.64±0.02 (P=0.02 vs control and P=0.04 vs aerobic). There were no significant differences in VAT, ApoA-1 or HSCRP levels between groups. CONCLUSIONS: Aerobic and resistance training and their combination decreased abdominal SAT in adolescents with obesity. Combined training caused greater improvements in ApoB/ApoA-1 ratio compared with aerobic training alone.

Effects of Caloric Restriction with or without Resistance Training in Dynapenic-Overweight and Obese Menopausal Women: A MONET Study.

OBJECTIVE: The dynapenic (DYN)-obese phenotype is associated with an impaired metabolic profile. However, there is a lack of evidences regarding the effect of lifestyle interventions on the metabolic profile of individual with dynapenic phenotype. The objective was to investigate the impact of caloric restriction (CR) with or without resistance training (RT) on body composition, metabolic profile and muscle strength in DYN and non-dynapenic (NDYN) overweight and obese menopausal women. DESIGN: 109 obese menopausal women (age 57.9 ± 9.0 yrs; BMI 32.1 ± 4.6 kg/m2) were randomized to a 6-month CR intervention with or without a RT program. Participants were categorized as DYN or NDYN based on the lowest tertile of relative muscle strength in our cohort (< 4.86 kg/BMI). MEASUREMENTS: Body composition was measured by DXA, body fat distribution by CT scan, glucose homeostasis at fasting state and during an euglycemic-hyperinsulinemic clamp, fasting lipids, resting blood pressure, fasting inflammation markers and maximal muscle strength. RESULTS: No difference was observed between groups at baseline for body composition and the metabolic profile. Overall, a treatment effect was observed for all variables of body composition and some variables of the metabolic profile (fasting insulin, glucose disposal, triglyceride levels, triglycerides/HDL-Chol ratio and resting diastolic blood pressure) (P between 0.05 and 0.001). No Group X Treatment interaction was observed for variables of body composition and the metabolic profile. However, an interaction was observed for muscle strength; which significantly improved more in the CR+RT NDYN group (all P ≤ 0.05). CONCLUSIONS: In the present study, dynapenia was not associated with a worse metabolic profile at baseline in overweight and obese menopausal women. DYN and NDYN menopausal women showed similar cardiometabolic benefit from CR or CR+RT interventions. However, our results showed that the addition of RT to CR was more effective in improving maximal strength in DYN and NDYN obese menopausal women.

Satiety quotient linked to food intake and changes in anthropometry during menopause: a MONET Study.

OBJECTIVES: It is unknown whether the satiety quotient (SQ) differs across the menopausal transition, and whether changes in SQ are related to changes in anthropometric/body composition variables. The objective of this study was to evaluate the changes in SQ and its association with energy intake and changes in anthropometric/body composition variables across the menopausal transition. METHODS: At baseline, 102 premenopausal women (aged 49.9 ± 1.9 years, body mass index 23.3 ± 2.2 kg/m(2)) took part in a 5-year observational, longitudinal study. Body composition (DXA), appetite (visual analog scales), energy and macronutrient intakes (ad libitum lunch and 7-day food diary) were assessed annually. The SQ (mm/100 kcal) was calculated at 60 and 180 min post-breakfast consumption. RESULTS: Overall, the SQ increased at years 3 and 4 (p = 0.01-0.0001), despite no significant differences between menopausal status groups. Lower fullness, prospective food consumption and mean SQ values predicted overall increases in lunch energy and macronutrient intakes (p = 0.04-0.01), whereas only prospective food consumption and fullness SQ predicted energy intake and carbohydrate intake, respectively, when assessed with food diaries (p = 0.01). Delta SQs were negatively correlated with changes in waist circumference (p = 0.03-0.02), whereas delta SQs were positively (p = 0.04) and negatively (p = 0.02) associated with delta fat mass between years 1 and 5, and years 4 and 5, respectively. CONCLUSION: These results suggest that variations in SQ across the menopausal transition are related to energy and macronutrient intakes and coincide with changes in body composition and waist circumference.

Effects of the menopausal transition on dietary intake and appetite: a MONET Group Study.

BACKGROUND/OBJECTIVE: The purpose of this study was to investigate changes in dietary intake and appetite across the menopausal transition. SUBJECTS/METHODS: This was a 5-year observational, longitudinal study on the menopausal transition. The study included 94 premenopausal women at baseline (age: 49.9±1.9 years; BMI: 23.3±2.3 kg/m2). Body composition (dual-energy X-ray absorptiometry), appetite (visual analogue scale), eating frequency, energy intake (EI) and macronutrient composition (7-day food diary and buffet-type meal) were measured annually. RESULTS: Repeated-measures analyses revealed that total EI and carbohydrate intake from food diary decreased significantly over time in women who became postmenopausal by year 5 (P>0.05) compared with women in the menopausal transition. In women who became postmenopausal by year 5, fat and protein intakes decreased across the menopausal transition (0.05>P<0.01). Although a decrease in % fat intake was observed during the menopausal transition (P<0.05), this variable was significantly increased in the postmenopausal years (P<0.05). Spontaneous EI and protein intake also declined over time and were higher in the years preceding menopause onset (P<0.05). Desire to eat, hunger and prospective food consumption increased during the menopausal transition and remained at this higher level in the postmenopausal years (0.05>P<0.001). Fasting fullness decreased across the menopausal transition (P<0.05). CONCLUSION: These results suggest that menopausal transition is accompanied with a decrease in food intake and an increase in appetite.

Light physical activity is a better determinant of lower adiposity during the menopausal transition.

OBJECTIVE: To investigate the relationship between time spent performing physical activity (PA) and adiposity across the menopausal transition. METHODS: Body weight and body composition were analyzed in 65 women (47-54 years old; body mass index 23.2 ± 2.4 kg/m(2)) in a 5-year prospective study. Time spent in PA of varying intensities (sedentary, light, moderate and vigorous) was determined from 7-day accelerometer measurement and energy intake with a 7-day food diary. RESULTS: Significant negative correlations were observed between the time spent in light-intensity PA and fat mass (FM) (r = -0.38, p < 0.005), central FM (r = -0.36, p < 0.005), peripheral FM (r = -0.33, p < 0.01), and percent body fat (r = -0.42, p < 0.001) at year 1, respectively. No significant correlations were noted between measures of adiposity and time spent performing either moderate or vigorous PA. Analyses using tertiles of time spent in light PA at year 1 showed that FM (20.7 ± 4.0 vs. 20.3 ± 6.6 vs. 16.6 ± 4.6 kg, p < 0.05), central FM (10.1 ± 2.6 vs. 10.0 ± 3.8 vs. 7.8 ± 2.4 kg; p < 0.05) and percent body fat (34.5 ± 5.1 vs. 32.2 ± 7.7 vs. 28.1 ± 6.2%, p < 0.01) were all significantly lower in women in the highest tertile. These differences remained significant after covariate analyses using time spent in moderate- and high-intensity PA and total energy intake. Finally, lower levels of FM, percent body fat, central and peripheral FM persisted in women who spent more time in light PA (highest tertiles) over the 5-year follow-up. CONCLUSION: Our results suggest that the time spent performing light PA may have a greater impact on adiposity than moderate and/or vigorous PA, an observation independent of the menopausal status.

A review of randomized controlled trials of aerobic exercise training on fitness and cardiometabolic risk factors in obese adolescents.

Aerobic training is the most prescribed exercise modality for the management of pediatric obesity. There is strong evidence that it decreases waist circumference, percent body fat and visceral fat, increases cardiorespiratory fitness, and decreases blood pressure in obese adolescents. However, the independent effects of aerobic exercise training on other cardiometabolic risk factors (ie, insulin resistance markers, plasma lipid levels, and inflammatory markers) are limited and yield inconsistent findings. Our article reviews randomized controlled trials evaluating the effects of aerobic exercise training on body composition, fitness, lipid levels, and insulin resistance in obese adolescents (aged 13-18 years) and outlines future research directions for this population.

Effects of the menopausal transition on energy expenditure: a MONET Group Study.

OBJECTIVES: Factors that influence weight gain during the menopausal transition are not fully understood. The purpose of this study was to investigate changes in energy expenditure (EE) across the menopausal transition. METHODS: In all, 102 premenopausal women (age: 49.9 ± 1.9 years; body mass index: 23.3 ± 2.2 kg/m(2)) were followed for 5 years. Body composition (dual-energy X-ray absorptiometry), physical activity EE (accelerometer), resting EE and thermic effect of food (indirect calorimetry) were measured annually. RESULTS: Total EE decreased significantly over time in postmenopausal women (P<0.05), which was mostly due to a decrease in physical activity EE (P<0.05). Although average resting EE remained stable over time in postmenopausal women, a significant increase, over the 5-year period, was noted in women who were in the menopausal transition by year 5 (P<0.05). Finally, the time spent in moderate physical activity decreased and the time spent in sedentary physical activity increased during the menopausal transition (P<0.05). CONCLUSION: These results suggest that menopausal transition is accompanied with a decline in EE mainly characterized by a decrease in physical activity EE and a shift to a more sedentary lifestyle.

Ovariectomy stimulates hepatic fat and cholesterol accumulation in high-fat diet-fed rats.

This study was designed to determine how estrogens withdrawal during a high-fat (HF) diet regimen affects liver triacylglycerol (TAG) and cholesterol accumulation. Female Sprague-Dawley rats were submitted to a HF (42% energy as fat) or a standard (SD) diet for 6 weeks before being either ovariectomized (Ovx) or sham operated (Sham). Thereafter, Ovx and Sham rats were kept on the same diet for another 6 weeks leading to euthanasia. Liver TAG content was increased (p<0.01) in Ovx rats but not by the HF diet alone. However, the combination of HF diet and Ovx resulted in a greater liver TAG accumulation (p<0.06) than that observed in Ovx-SD/SD. Measurement of molecular markers of liver lipid metabolism revealed an increase in transcripts of markers of lipid oxidation (CPT-1 and PGC1; p<0.05) in rats fed the HF diet. This increase was, however, substantially less if HF fed rats were Ovx. Liver total cholesterol levels were increased (p<0.01) only in the Ovx-HF/HF rats while plasma cholesterol levels were increased in Ovx-SD/SD and in SHAM-HF/HF and Ovx-HF/HF rats. Transcripts of molecular markers of cholesterol metabolism suggest that biliary acids synthesis (CYP7a-1) was reduced in Ovx-SD/SD and Sham-HF/HF rats and even more so in Ovx-HF/HF rats. It is concluded that the effects of a HF diet on liver TAG accumulation are especially observed in Ovx rats possibly through a reduction in hepatic lipid oxidation. The combination of Ovx and HF diet also acts synergistically to favor liver cholesterol accumulation.

Healthy Eating, Aerobic and Resistance Training in Youth (HEARTY): study rationale, design and methods.

PURPOSE: The objective of the Healthy Eating Aerobic and Resistance Training in Youth (HEARTY) trial (ClinicalTrials.Gov # NCT00195858) was to examine the effects of resistance training, with and without aerobic training, on percent body fat in sedentary, post-pubertal overweight or obese adolescents aged 14-18 years. This paper describes the HEARTY study rationale, design and methods. METHODS: After a 4-week supervised low-intensity exercise run-in period, 304 overweight or obese adolescents with a body mass index≥85th percentile for age and sex were randomized to 4 groups for 22 weeks (5 months): diet+aerobic exercise, diet+resistance exercise, diet+combined aerobic and resistance exercise, or a diet only waiting-list control. All participants received dietary counseling designed to promote healthy eating with a maximum daily energy deficit of -250 kcal. OUTCOMES: The primary outcome is percent body fat measured by Magnetic Resonance Imaging. Secondary outcomes include changes in anthropometry, regional body composition, resting energy expenditure, cardiorespiratory fitness, musculoskeletal fitness, cardiometabolic risk markers, and psychological health. SUMMARY: To our knowledge, HEARTY is the largest clinical trial examining effects of aerobic training, resistance training, and combined aerobic and resistance training on changes in adiposity and cardiometabolic risk markers in overweight and obese adolescents. The findings will have important clinical implications regarding the role that resistance training should play in the management of adolescent obesity and its co-morbidities.

Evaluation of two new surrogate indices including parameters not using insulin to assess insulin sensitivity/resistance in non-diabetic postmenopausal women: a MONET group study.

AIM: The study evaluated and compared, with other surrogate indices of insulin sensitivity/resistance (IS/R), the relevance of the TyG index, a product of fasting glucose and triglyceride (TG) levels, and the EGIR index, which includes TG, high-density lipoprotein cholesterol (HDL-c) and waist circumference in its formula to estimate IS/R, in non-diabetic postmenopausal women. METHODS: A secondary analysis was performed using the baseline data for 163 non-diabetic postmenopausal women from the Montreal-Ottawa New Emerging Team (MONET) population database. The subjects participated in hyperinsulinaemic-euglycaemic (HIEG) clamp and oral glucose tolerance (OGTT) tests. Correlations and comparisons between surrogate indices were performed in addition to inter-rater agreement tests. The optimal value of surrogate indices for diagnosis of IS/R was established on a receiver operating characteristic (ROC) scatter plot. RESULTS: A significant correlation was found between the HIEG clamp and all IS/R surrogate indices tested [r=-0.370 (TyG index) to 0.608 (SIisOGTT index); P<0.001]. On ROC curve analysis, a higher AUROC was found for SIisOGTT (0.791) than for TyG and EGIR (0.706 and 0.675, respectively; P=0.07 and P<0.05, respectively). CONCLUSION: The TyG and EGIR IS/R indices were only relatively modestly related to the HIEG clamp. In contrast, both fasting- and OGTT-derived IS/R surrogate indices, which include insulin values in their formulae, appeared to be more accurate in estimating IS/R in our study population. Thus, the TyG and EGIR IS/R indices need to be tested and validated more extensively in different populations before being put to large-scale clinical use.

Overweight and obese teenagers: why is adolescence a critical period?

This paper discusses the critical period of adolescence and its potential role in the development and persistence of obesity. The adolescent years are characteristic of changes in body composition (location and quantity of body fat), physical fitness and decreased insulin sensitivity during puberty. This period of growth and maturation is also marked with behavioural changes in diet, physical activity, sedentary behaviour and psychological health. Physical activity and sport participation decline during adolescence especially in teenage girls, while sedentary behaviour, risk for depression and body esteem issues increase during the teenage years. These physiological and behavioural changes during adolescence warrant the attention of health practitioners to prevent the onset and continuation of obesity throughout the lifespan.

Liver fat accumulation may be dissociated from adiposity gain in ovariectomized rats.

OBJECTIVE: The purpose of the present study was to establish a model of rats prone and resistant to intra-abdominal fat accumulation in response to ovariectomy (Ovx-P and Ovx-R) and to determine its relationship with molecular biomarkers. DESIGN: Two experiments were conducted in which female rats were either sham-operated (Sham) or ovariectomized (Ovx). In the first experiment, ovariectomized rats were stratified into three tertiles based on intra-abdominal adipose tissue mass. To strengthen the Ovx-P/Ovx-R model, we conducted a second experiment in which the numbers of rats in each group were extended and in which different molecular markers were measured. At the end of a 6-8-week period, ovariectomized rats that displayed the lower abdominal fat accumulation (lower tertile) were labelled as Ovx-R and those in the upper tertile as Ovx-P. RESULTS: Ovx-R rats displayed similar abdominal fat gain to Sham rats whereas Ovx-P rats depicted abdominal fat mass twice as high as that of Sham and Ovx-R rats. Despite the difference in abdominal adiposity, liver fat content was ~50% higher (p < 0.01) in both Ovx-R and Ovx-P rats compared to Sham rats. In addition, both Ovx-R and Ovx-P rats depicted higher HOMA-IR scores (p < 0.05) and lower (p < 0.01) hepatic gene expression of leptin receptor-b and -e, microsomal transfer protein (MTP), and diacylglycerol acyltransferase-2 (DGAT-2) compared to Sham rats. CONCLUSION: The present findings indicate that estrogen withdrawal-induced hepatic steatosis and associated insulin resistance may be dissociated from abdominal fat accumulation and suggest that a decrease in leptin action through a down-regulation of leptin receptors and a decrease in very low density lipoprotein production through a down-regulation of MTP and DGAT-2 may be factors responsible for this observation in the absence of peripheral fat gain.

Excessive gestational weight gain predicts large for gestational age neonates independent of maternal body mass index.

OBJECTIVE: To determine the effects of maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) on large-for-gestational-age (LGA) birth weight (≥90th % ile). METHODS: We examined 4321 mother-infant pairs from the Ottawa and Kingston (OaK) birth cohort. Multivariate logistic regression (controlling for gestational and maternal age, pre-pregnancy weight, parity, smoking) were performed and odds ratios (ORs) calculated. RESULTS: Prior to pregnancy, a total of 23.7% of women were overweight and 16.2% obese. Only 29.3% of women met GWG targets recommended by the Institute of Medicine (IOM), whereas 57.7% exceeded the guidelines. Adjusting for smoking, parity, age, maternal height, and achieving the IOM's recommended GWG, overweight (OR 1.99; 95%CI 1.17-3.37) or obese (OR 2.64; 95% CI 1.59-4.39) pre-pregnancy was associated with a higher rate of LGA compared to women with normal BMI. In the same model, exceeding GWG guidelines was associated with higher rates of LGA (OR 2.86; 95% CI 2.09-3.92), as was parity (OR 1.49; 95% CI 1.22-1.82). Smoking (OR 0.53; 95%CI 0.35-0.79) was associated with decreased rates of LGA. The adjusted association with LGA was also estimated for women who exceeded the GWG guidelines and were overweight (OR 3.59; 95% CI 2.60-4.95) or obese (OR 6.71; 95% CI 4.83-9.31). CONCLUSION: Pregravid overweight or obesity and gaining in excess of the IOM 2009 GWG guidelines strongly increase a woman's chance of having a larger baby. Lifestyle interventions that aim to optimize GWG by incorporating healthy eating and exercise strategies during pregnancy should be investigated to determine their effects on LGA neonates and down-stream child obesity.

Accuracy of the SenseWear Armband™ during ergocycling.

The present study aims to show the accuracy of a portable motion sensor, the SenseWear Armband, for the estimation of energy expenditure vs. energy expenditure measured by indirect calorimetry during ergocycling. 31 healthy adults (52% women; age: 26.7±6.3 years; Body Mass Index: 23.9±3.3 kg/m2) completed a 45-min ergocycling session at 50% of their VO2(peak). Despite a significant underestimation of 18.7±13.2 kcal during the first 10 min of the activity (T=5.06; p<0.001), we observed an overall good agreement between energy expenditure estimated by the SenseWear Armband during ergocycling and indirect calorimetry (260.3±80.1 vs. 287.8±97.1 kcal, respectively) (T=-2.148; p=0.04) and a significant intra-class correlation (r=0.81; p<0.001). The results of the present study indicate that the SenseWear Armband underestimated energy expenditure during a 45-min ergocycling session at a 50% VO2(peak) intensity, mainly during the first 10 min. Underestimation at the onset of the activity warrants further research.

Associations between physical fitness and HbA1(c) in type 2 diabetes mellitus.

AIM/HYPOTHESIS: In people with type 2 diabetes, exercise improves glucose control (as reflected in HbA1(c)) and physical fitness, but it is not clear to what extent these exercise-induced improvements are correlated with one another. We hypothesised that reductions in HbA1(c) would be related: (1) to increases in aerobic fitness and strength respectively in patients performing aerobic training or resistance training; and (2) to changes in strength and aerobic fitness in patients performing aerobic and resistance training. METHODS: We randomly allocated 251 type 2 diabetes patients to aerobic, resistance, or aerobic plus resistance training, or to a sedentary control group. Peak oxygen consumption VO2(peak), workload, treadmill time and ventilatory threshold measurements from maximal treadmill exercise testing were measured at baseline and 6 months. Muscular strength was measured as the maximum weight that could be lifted eight times on the leg press, bench press and seated row exercises. RESULTS: With aerobic training, significant associations were found between changes in both VO2(peak) (p = 0.040) and workload (p = 0.022), and changes in HbA1(c.) With combined training, improvements in VO2(peak) (p = 0.008), workload (p = 0.034) and ventilatory threshold (p = 0.003) were significantly associated with changes in HbA1(c.) Increases in strength on the seated row (p = 0.006) and in mid-thigh muscle cross-sectional area (p = 0.030) were significantly associated with changes in HbA1(c) after resistance exercise, whereas the association between increases in muscle cross-sectional area and HbA1(c) in participants doing aerobic plus resistance exercise (p = 0.059) was of borderline significance. CONCLUSIONS/INTERPRETATION: There appears to be a link between changes in fitness and HbA1(c). The improvements in cardiorespiratory fitness with aerobic training may be a better predictor of changes in HbA1(c) than improvements in strength.