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This cardiometabolic imaging study was designed to document the adaptation of middle-aged recreational cyclists to a large exercise prescription not aiming at weight loss. Eleven middle-aged recreational male cyclists traveled 1,144 km over seven consecutive days. A comprehensive cardiometabolic profile including visceral and ectopic adiposity assessed by magnetic resonance imaging was obtained at baseline and following the exercise week. Cardiorespiratory fitness (CRF) was measured using maximal cardiopulmonary exercise testing. During the week, heart rate was monitored to calculate individual energy expenditure. Baseline characteristics of cyclists were compared to 86 healthy males with the same age range. Cyclists presented higher baseline CRF (+9.2 mL/kg/min, p<0.0001) and lower subcutaneous (-56.2 mL, p<0.05) and liver fat (-3.3%, p<0.05) compared to the reference group. Despite the large energy expenditure during the cycling week, the increase in energy intake limited decreases in body weight (-0.8±0.9 kg, p<0.05) and body mass index (-0.3±0.3 kg/m2, p<0.05). Loss of fat mass (-1.5±1.0 kg, p<0.001) and a trend toward an increased lean mass (+0.8±1.2 kg, p<0.07) were observed. Visceral adiposity (-14.1±14.2 mL, p<0.01) and waist circumference (-3.2±1.7 cm, p<0.0001) decreased while subcutaneous (-2.7±5.1 mL, NS), liver (-0.5±0.9%, NS) and cardiac fat (-0.3±2.3 mL, NS) remained unchanged. This cardiometabolic imaging study documents middle-aged recreational cyclists' subcutaneous and visceral adiposity as well as cardiac and liver fat responses to a large volume of endurance exercise despite an increase in energy intake aimed at limiting weight loss.
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BACKGROUND: Maple syrup, a minimally transformed sweetener rich in polyphenols, can exert a prebiotic-like action and improve metabolic parameters in animal models. However, no randomized clinical trial has investigated the impact of replacing refined sugars with maple syrup on cardiometabolic risk factors and gut microbiota composition. AIMS, MATERIALS AND METHODS: In a randomized, double-blind, controlled crossover trial with 42 overweight adults with mild cardiometabolic alterations, participants were instructed to substitute 5% of their total caloric intake from added sugars with either maple syrup or an artificially flavored sucrose syrup for eight weeks. The primary outcome included changes in glucose homeostasis while secondary outcomes were changes in other cardiometabolic risk factors such as blood pressure, anthropometric indices, and blood lipid profiles. Exploratory outcomes involved analyzing changes in gut microbiota composition. RESULTS: Replacing refined sugars with maple syrup over eight weeks decreased the glucose area under the curve when compared to substituting refined sugars with sucrose syrup, as determined during the oral glucose tolerance test, leading to a significant difference between the intervention arms (-50.59±201.92 vs 29.93±154.90, P<.047). Substituting refined sugar with maple syrup also significantly decreased android fat mass (-7.83±175.05 vs 67.61± 206.71 g, P = 0.02) and systolic blood pressure (-2.72±8.73 vs 0.87±8.99 mmHg, P=0.03). No changes in the blood lipid profile were observed. As an exploratory outcome, we further observed that substituting refined sugars with maple syrup promoted selective taxonomic changes in the gut microbiota such as a significant reduction in the abundance of Klebsiella and decreased microbial functions associated with bacterial-induced cytokine response, as compared to substitution with sucrose syrup. CONCLUSION: Substituting refined sugars with maple syrup in individuals with mild metabolic alterations resulted in a significantly greater reduction of key cardiometabolic risk factors as compared to substitution with sucrose syrup, in association with specific changes in gut microbiota. The role of the gut microbiota in these effects remains to be further explored. CLINICAL TRIAL REGISTRATION: clinicaltrials.gov as NCT04117802.
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The worldwide prevalence of individuals with an elevated body weight has increased steadily over the past five decades. Billions of research dollars have been invested to improve our understanding of the causes and consequences of having an elevated body weight. All this knowledge has, however, failed to influence populational body weight trajectories of most countries around the world. Research on the definition of "obesity" has also evolved. Body mass index (BMI), the most commonly used tool to make its diagnosis, has major limitations. In this review article, we will highlight evidence from observational studies, genetic association studies and randomized clinical trials that have shown the remarkable inter-individual differences in the way humans store energy as body fat. Increasing evidence also suggests that, as opposed to weight inclusive, lifestyle-based approaches, weight-centric approaches advising people to simply eat less and move more are not sustainable for most people for long-term weight loss and maintenance. It is time to recognize that this outdated approach may have produced more harm than good. On the basis of pathophysiological, genetic and clinical evidence presented in this review, we propose that it may be time to shift away from the traditional clinical approach, which is BMI-centric. Rather, emphasis should be placed on actionable lifestyle-related risk factors aiming at improving overall diet quality and increasing physical activity level in the general population.
Assuntos
Adiposidade , Aterosclerose , Índice de Massa Corporal , Diabetes Mellitus Tipo 2 , Obesidade , Humanos , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/diagnóstico , Obesidade/epidemiologia , Obesidade/fisiopatologia , Aterosclerose/epidemiologia , Medição de Risco , Fatores de Risco , Comportamento de Redução do Risco , Fatores de Risco de Doenças CardíacasRESUMO
The SYNERGIE study documented the effects on cardiometabolic risk (CMR) indices of a 1-year lifestyle intervention targeting physical activity (PA) and diet followed by a 2-year maintenance period in men with visceral obesity. Improvements in CMR markers and a decrease in low-attenuation muscle (LAM) area were observed after 1 year. Despite a rebound in visceral adipose tissue (VAT) during the maintenance period, insulin resistance (IR) improved. We tested the hypothesis that variations in cardiorespiratory fitness (CRF) and LAM could explain the long-term improvement in IR. A health (n = 88; mean age 49.0 ± 8.2 years) and fitness (n = 72) evaluation was performed at 0, 1, and 3 years. Participants were classified into two groups based on their CRF response over the maintenance period (worsening: CRF- vs. maintenance/improvement: CRF+). During the maintenance period, changes in the psoas and core LAM areas correlated with changes in IR (r = 0.27; p < 0.05 and r = 0.34; p < 0.005) and changes in CRF (r = -0.31; p < 0.01 and r = -0.30; p < 0.05). IR improved in the CRF+ group (p < 0.05) but remained stable in the CRF- group. Men in the CRF+ group regained half of the changes in VAT volume and LAM at the psoas and mid-thigh compared to the CRF- group (p < 0.05). These results support the importance of targeting VAT and CRF/PA for the long-term management of CMR in men with visceral obesity.
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Aptidão Cardiorrespiratória , Resistência à Insulina , Gordura Intra-Abdominal , Obesidade Abdominal , Humanos , Masculino , Obesidade Abdominal/terapia , Obesidade Abdominal/fisiopatologia , Aptidão Cardiorrespiratória/fisiologia , Pessoa de Meia-Idade , Adulto , Exercício Físico/fisiologia , Fatores de Risco CardiometabólicoRESUMO
La obesidad visceral se asocia a anormalidades metabólicas aumentando el riesgo de diabetes de tipo 2 y de coronariopatía (CP). El Estudio Cardiovascular de Québec demostró que la tríada metabólica aterogénica (TMA) presente en hombres visceralmente obesos (VO), incrementa 20 veces el riesgo de CP durante un período de 5 años. Fue desarrollado un algoritmo de detección precoz a fin de identificar individuos que podrían ser portadores de estas anormalidades aterogénicas. Fue descubierto que la presencia simultánea de una circunferencia de la cintura elevada y una hipertrigliceridemia moderada ("cintura hipertrigliceridémica" - CH) podrían identificar adecuadamente a una proporción significativa de portadores de la TMA. Es importante dejar claro, que incluso en ausencia de los clásicos factores de riesgo los pacientes VO pueden tener un riesgo elevado de CP si presentan la CH. Finalmente, se ha sugerido que el riesgo de desarrollar un síndrome coronario agudo en pacientes VO no está siempre relacionado al grado de estenosis coronaria y debería considerarse el perfil aterotrombótico/inflamatorio del paciente en la valoración del riesgo. La estabilización de la placa aterosclerótica se convertiría en un objetivo terapéutico legítimo y más factible para la prevención de la CP en los pacientes VO