Effets de l'entraînement en résistance sur le regain de poids et l'inflammation chez des femmes post-ménopausées en surpoids ou obèses

Objectifs: Évaluer si un programme d’entraînement en résistance d’une durée d’un an prévient le regain de poids et majore l’amélioration du profil inflammatoire. Le second objectif de cette étude était de déterminer si la variation du tissu adipeux viscéral est associée aux changements dans les concentrations sanguines des marqueurs inflammatoires. Méthodes: Soixante-dix femmes post-ménopausées en surpoids ou obèses ont été randomisées dans un des deux groupes suivants : (1) Contrôle ou (2) Entraînement en résistance. La composition corporelle (absorptiométrie double à rayons X et tomographie axiale) et les marqueurs inflammatoires (protéine C-réactive, orosomucoïde, haptoglobine) ont été évalués avant et après la période de suivi d’une durée d’un an. Résultats: Suite à la période de suivi, un regain significatif de poids corporel et de masse grasse était observé dans le groupe contrôle et le groupe entraînement en résistance (p < 0,05). Une réduction des concentrations sériques de l’orosomucoïde et une hausse des niveaux sériques de l’haptoglobine étaient également notées dans les deux groupes (p < 0,05). La variation du tissu adipeux viscéral était seulement associée aux changements dans les concentrations sériques de la protéine C-réactive (r = 0,373, p < 0,05). Conclusion: Nos résultats suggèrent que l’entraînement en résistance ne prévient pas le regain de poids corporel et ne majore pas l’amélioration du profil inflammatoire chez des femmes post-ménopausées en surpoids ou obèses. De plus, nos résultats indiquent que la variation du tissu adipeux viscéral ne semble pas être un facteur clé impliqué dans les changements des concentrations sanguines des marqueurs inflammatoires.Objectives: To evaluate if a 1-year resistance training program improved weight loss maintenance and the inflammatory profile in overweight and obese postmenopausal women. The second objective of this study was to determine if the variation in visceral adipose tissue was associated with the changes in inflammatory markers concentrations. Methods: Seventy overweight and obese postmenopausal women were randomized to a control group or a resistance training group. Body composition (dual energy X-ray absorptiometry and computed tomography) and inflammatory markers (C-reactive protein, orosomucoid, haptoglobin) were measured before and after the 1-year weight loss maintenance intervention. Results: Following the weight loss maintenance intervention, we observed a significant body weight and fat mass regain in the control group and the resistance training group (p < 0.05). Significant reductions in orosomucoid and increases in haptoglobin concentrations were noted in both groups (p < 0.05). The variation in visceral adipose tissue was only associated with the changes in C-reactive protein concentrations (r = 0,373, p < 0.05). Conclusion: Our results suggest that resistance training do not improve weight loss maintenance and the inflammatory profile in overweight and obese postmenopausal women. Moreover, our results indicate that the variation in visceral adipose tissue may not be a key factor implicated in the changes in inflammatory markers concentrations

Association between Abdominal Fat (DXA) and Its Subcomponents (CT Scan) before and after Weight Loss in Obese Postmenopausal Women: A MONET Study

Introduction. Subcutaneous fat (ScF) and visceral fat (VF) measurements using CT scan are expensive and may imply significant radiation doses. Cross-sectional studies using CT scan showed that ScF and VF are significantly correlated with abdominal fat measured by DXA (AF-DXA). The association has not been studied after a weight loss. Objective. To determine (1) the associations between AF-DXA and ScF and VF before and after weight loss and (2) the associations between their changes. Methods. 137 overweight/obese postmenopausal women were divided in two groups (1-caloric restriction or 2-caloric restriction + resistance training). AF was assessed using DXA and CT scan. Results. Correlations between AF-DXA and ScF (before: r = 0.87, after; r = 0.87; P < .01) and, AF-DXA and VF (before: r = 0.61, after; r = 0.69; P < .01) are not different before and after the weight loss. Correlations between delta AF-DXA and delta ScF (r = 0.72; P < .01) or delta VF (r = 0.51; P < .01) were found. Conclusion. The use of AF-DXA as a surrogate for VF after weight loss is questionable, but may be interesting for ScF

Association between Abdominal Fat (DXA) and Its Subcomponents (CT Scan) before and after Weight Loss in Obese Postmenopausal Women: A MONET Study

Introduction. Subcutaneous fat (ScF) and visceral fat (VF) measurements using CT scan are expensive and may imply significant radiation doses. Cross-sectional studies using CT scan showed that ScF and VF are significantly correlated with abdominal fat measured by DXA (AF-DXA). The association has not been studied after a weight loss. Objective. To determine (1) the associations between AF-DXA and ScF and VF before and after weight loss and (2) the associations between their changes. Methods. 137 overweight/obese postmenopausal women were divided in two groups (1-caloric restriction or 2-caloric restriction + resistance training). AF was assessed using DXA and CT scan. Results. Correlations between AF-DXA and ScF (before: r = 0.87, after; r = 0.87; P &lt; .01) and, AF-DXA and VF (before: r = 0.61, after; r = 0.69; P &lt; .01) are not different before and after the weight loss. Correlations between delta AF-DXA and delta ScF (r = 0.72; P &lt; .01) or delta VF (r = 0.51; P &lt; .01) were found. Conclusion. The use of AF-DXA as a surrogate for VF after weight loss is questionable, but may be interesting for ScF

Comparing composition and structure in old-growth and harvested (selection and diameter-limit cuts) northern hardwood stands in Quebec

Single-tree selection cutting is sometimes believed to be similar to the natural gap disturbance regime of hardwood forests, but few studies have specifically compared the compositional and structural characteristics of old-growth hardwood stands, undergoing natural gap dynamics and hardwood stands previously subjected to partial cuts. This study characterized and compared the composition (saplings and trees) and structure (gaps, foliage distribution, tree diameter and density, snags and coarse woody debris) of old-growth stands (OG), 12-year-old selection cuts (SC), and 28-33-year-old diameter-limit cuts (DLC) in sugar maple (Acer saccharum)-dominated northern hardwood stands. Results showed marked structural differences between OG and harvested stands, with stronger differences between DLC and OG than between SC and OG. The synchronized formation of numerous canopy openings in harvested stands induced a massive post-harvest recruitment of advance regeneration in both SC and DLC that created a dense foliage layer in the understory. Large living trees (dbh > 39.1 cm) and defective trees were less numerous in SC than OG, which can have a detrimental impact on species dependent on these structural elements, and on the future availability and characteristics of coarse woody debris. Relatively few compositional differences were noticed among stand types, although a greater proportion of mid-tolerant species was found in the post-harvest recruitment cohorts of harvested stands compared to OG, and a lower proportion of beech (Fagus grandifolia Ehrh.) saplings was observed in DLC compared to OG and SC. We argue that even if selection cutting is closer to the natural disturbance regime of hardwood forests than diameter-limit cutting, and therefore representing progress toward the development and implementation of a natural-disturbance-based management, a recurring application of selection cutting might lead to a homogenization of forest structure and composition, a reduction of key structural features and a reduction in biological diversity at both the stand and landscape scales. Some management recommendations are proposed

Non-severe hypoglycemia in type 1 diabetes: a randomized crossover trial comparing two quantities of oral carbohydrates at different insulin-induced hypoglycemia ranges

AimsNon-severe hypoglycemia (NS-H) is challenging for people living with type 1 diabetes (PWT1D) and often results from relative iatrogenic hyper-insulinemia. Current guidelines recommend a one-size-fits-all approach of 15–20 g of simple carbohydrates (CHO) every 15 min regardless of the triggering conditions of the NS-H event. We aimed to test different amounts of CHO to treat insulin-induced NS-H at various glucose ranges.MethodsThis is a randomized, four-way, crossover study involving PWT1D, testing NS-H treatment outcomes with 16 g vs. 32 g CHO at two plasma glucose (PG) ranges: A: 3.0–3.5 mmol/L and B: &lt;3.0 mmol/L. Across all study arms, participants consumed an additional 16 g of CHO if PG was still &lt;3.0 mmol/L at 15 min and &lt;4.0 mmol/L at 45 min post-initial treatment. Subcutaneous insulin was used in a fasting state to induce NS-H. Participants had frequent venous sampling of PG, insulin, and glucagon levels.ResultsParticipants (n = 32; 56% female participants) had a mean (SD) age of 46.1 (17.1) years, had HbA1c at 54.0 (6.8 mmol/mol) [7.1% (0.9%)], and had a diabetes duration of 27.5 (17.0) years; 56% were insulin pump users. We compared NS-H correction parameters between 16 g and 32 g of CHO for range A, 3.0–3.5 mmol/L (n = 32), and range B, &lt;3.0 mmol/L (n = 29). Change in PG at 15 min for A: 0.1 (0.8) mmol/L vs. 0.6 (0.9) mmol/L, p = 0.02; and for B: 0.8 (0.9) mmol/L vs. 0.8 (1.0) mmol/L, p = 1.0. Percentage of participants with corrected episodes at 15 min: (A) 19% vs. 47%, p = 0.09; (B) 21% vs. 24%, p = 1.0. A second treatment was necessary in (A) 50% vs. 15% of participants, p = 0.001; (B) 45% vs. 34% of participants, p = 0.37. No statistically significant differences in insulin and glucagon parameters were observed.ConclusionsNS-H, in the context of hyper-insulinemia, is difficult to treat in PWT1D. Initial consumption of 32 g of CHO revealed some advantages at the 3.0–3.5 mmol/L range. This was not reproduced at lower PG ranges since participants needed additional CHO regardless of the amount of initial consumption.Clinical trial registrationClinicalTrials.gov, identifier NCT03489967

724-P: Timing of Basal Insulin Reduction to Prevent Hypoglycemia during Exercise in Adults and Adolescents with Type 1 Diabetes Using Insulin Pump Therapy: Preliminary Results

International audienceBackground We have shown that the reduction of basal insulin (-80%) 40-min before exercise is insufficient to reduce the time spent on hypoglycemia (Roy-Fleming et al., 2018. Diabetes and Metabolism). These results suggest that earlier basal insulin reductions need to be tested. We compared the efficacy of two timings to decrease basal insulin infusion rate to reduce exercise-induced hypoglycemia in patients with T1D using insulin pump therapy. Furthermore, we explored if decreased muscle vasoreactivity (secondary to decreased insulin levels) is associated with a reduced time spent in hypoglycemia. Methods: 13 adults and adolescents (10 adults; 5 adolescents; mean A1C: 8,2±1,0%) practiced 60-min exercise sessions (ergocyle) at 60% VO2peak, 240 minutes after a standardized lunch. In randomized order, we compared an 80% reduction of basal insulin applied 40-min (T-40) and 90-min (T-90) before exercise onset. Near-infrared spectroscopy (NIRS) was used to investigate muscle hemodynamic at vastus lateralis. Venous blood samples for glycemia measurement were drawn every 10 min during exercise. Results: T-90 strategy could reduce hypoglycemia risk during exercise: glycemic drop during exercise tend to be more important during T-40 vs. T-90 strategy (-41.44 ± 57.65 mg/dl vs. -14.05 ± 34.23 mg/dl respectively; p=0.09). This trend is confirmed by the repeated measures ANOVA test, which shows a significant interaction effects (blood glucose level during exercise × strategy “T90 vs. T-40”) (p = 0.01). However, contrary to our hypothesis, the estimation of local muscle perfusion measured by NIRS shows comparable results between 2-strategies. Conclusion: Our preliminary results in 15 DT1 patients (planned 20) show that decreasing basal insulin infusion rate by 80% up to 90 minutes before exercise onset tend to reduce exercise-induced hypoglycemia. This drop does not seem to be related to a decrease in local muscle perfusion

Changes in Accuracy of Continuous Glucose Monitoring Using Dexcom G4 Platinum Over the Course of Moderate Intensity Aerobic Exercise in Type 1 Diabetes

International audienceAbstract Although the O‐GlcNAcylation process was discovered in 1984, its potential role in the physiology and physiopathology of skeletal muscle only emerged 20 years later. An increasing number of publications strongly support a key role of O‐GlcNAcylation in the modulation of important cellular processes which are essential for skeletal muscle functions. Indeed, over a thousand of O‐GlcNAcylated proteins have been identified within skeletal muscle since 2004, which belong to various classes of proteins, including sarcomeric proteins. In this review, we focused on these myofibrillar proteins, including contractile and structural proteins. Because of the modification of motor and regulatory proteins, the regulatory myosin light chain (MLC2) is related to several reports that support a key role of O‐GlcNAcylation in the fine modulation of calcium activation parameters of skeletal muscle fibres, depending on muscle phenotype and muscle work. In addition, another key function of O‐GlcNAcylation has recently emerged in the regulation of organization and reorganization of the sarcomere. Altogether, this data support a key role of O‐GlcNAcylation in the homeostasis of sarcomeric cytoskeleton, known to be disturbed in many related muscle disorders