Cold-induced changes in plasma signaling lipids are associated with a healthier cardiometabolic profile independently of brown adipose tissue.

Cold exposure activates brown adipose tissue (BAT) and potentially improves cardiometabolic health through the secretion of signaling lipids by BAT. Here, we show that 2 h of cold exposure in young adults increases the levels of omega-6 and omega-3 oxylipins, the endocannabinoids (eCBs) anandamide and docosahexaenoylethanolamine, and lysophospholipids containing polyunsaturated fatty acids. Contrarily, it decreases the levels of the eCBs 1-LG and 2-LG and 1-OG and 2-OG, lysophosphatidic acids, and lysophosphatidylethanolamines. Participants overweight or obese show smaller increases in omega-6 and omega-3 oxylipins levels compared to normal weight. We observe that only a small proportion (∼4% on average) of the cold-induced changes in the plasma signaling lipids are slightly correlated with BAT volume. However, cold-induced changes in omega-6 and omega-3 oxylipins are negatively correlated with adiposity, glucose homeostasis, lipid profile, and liver parameters. Lastly, a 24-week exercise-based randomized controlled trial does not modify plasma signaling lipid response to cold exposure.

Metabolic rate in sedentary adults, following different exercise training interventions: The FIT-AGEING randomized controlled trial.

BACKGROUND & AIMS: This study compares the influence of different exercise training programs on basal metabolic rate (BMR) and fat oxidation, in basal conditions (BFox) and during exercise (MFO), in sedentary, middle-aged adults. METHODS: The study subjects of this 12 week-long, randomised controlled trial, were 71 middle-aged adults (age 53.5 ± 4.9 years; 52% women). Subjects were randomly assigned to one of the following groups: (1) no exercise, (2) concurrent training based on international physical activity recommendations (PAR group), (3) high intensity interval training (HIIT group), and (4) high intensity interval training plus whole-body electromyostimulation (HIIT + EMS group). Subject BMR, BFox and MFO were determined by indirect calorimetry before and after the intervention. RESULTS: The HIIT + EMS subjects showed significant increases in BFox following the intervention compared with the control group (all P = 0.043); no such differences were seen in the PAR and HIIT compared with the control group (all P ≥ 0.1). A significant increase in post-intervention MFO was noted for the HIIT and HIIT + EMS group compared to the non-exercise control group (P < 0.05); no such difference was seen in the PAR group compared to the control group (all P ≥ 0.05). CONCLUSIONS: Twelve weeks of high intensity interval training plus whole-body electromyostimulation may increase the BFox and MFO of middle-aged sedentary adults. These findings have important clinical implications; a well-designed high-intensity interval training program plus whole-body electromyostimulation might be followed to help combat the appearance of chronic metabolic diseases characterized by metabolic inflexibility in middle-aged sedentary adults, though it will be necessary to determine how long the effects last.

Activation of Human Brown Adipose Tissue by Capsinoids, Catechins, Ephedrine, and Other Dietary Components: A Systematic Review.

Human brown adipose tissue (BAT) has attracted clinical interest not only because it dissipates energy but also for its potential capacity to counteract obesity and related metabolic disorders (e.g., insulin resistance and dyslipidemia). Cold exposure is the most powerful stimulus for activating and recruiting BAT, and this stimulatory effect is mediated by the transient receptor potential (TRP) channels. BAT can also be activated by other receptors such as the G-protein-coupled bile acid receptor 1 (GPBAR1) or ß-adrenergic receptors. Interestingly, these receptors also interact with several dietary components; in particular, capsinoids and tea catechins appear to mimic the effects of cold through a TRP-BAT axis, and they consequently seem to decrease body fat and improve metabolic blood parameters. This systematic review critically addresses the evidence behind the available human studies analyzing the effect of several dietary components (e.g., capsinoids, tea catechins, and ephedrine) on BAT activity. Even though the results of these studies are consistent with the outcomes of preclinical models, the lack of robust study designs makes it impossible to confirm the BAT-activation capacity of the specified dietary components. Further investigation into the effects of dietary components on BAT is warranted to clarify to what extent these components could serve as a powerful strategy to treat obesity and related metabolic disorders.

Evaluación de la capacidad cardiorrespiratoria en niños de edad preescolar: adaptación del test de 20m de ida y vuelta / Assessment of cardiorspiratory fitness in preschool children: adaptation of the 20 metres shuttle run test

La capacidad cardiorrespiratoria es un potente indicador de salud presente y futura en niños y adolescentes, sin embargo se desconoce si también lo es para niños de edad reescolar, de 3 a 5 años. En el presente estudio, describimos la adaptación a preescolares del test original de 20m de ida y vuelta, su viabilidad y asimilación en niños de 3 a 5 años, así como su maximalidad y fiabilidad. Un total de 130 alumnos (4,91 ± 0,89 años; 77 niños), realizaron el test dos veces, con dos semanas de separación. La adaptación del test consistió principalmente en reducir la velocidad inicial de 8,5 km/h a 6,5 km/h. El test fue viable y tuvo una buena asimilación tanto en niños como en niñas y en los tres grupos de edad, 3, 4 y 5 años. La frecuencia cardíaca máxima (FCmáx) alcanzada para la muestra completa fue de 199,4 ± 12,5 latidos/minuto, equivalente a un 97% de la FCmáx teórica estimada, y sin diferencias significativas por sexo o edad. La diferencia de medias test-retest (error sistemático) en el número de vueltas alcanzado fue de 2 vueltas, sin diferencias por sexo o edad. No hubo evidencia de heterocedasticidad. Nuestros resultados sugieren que el test es máximo y fiable en este grupo de edad. Futuros estudios de intervención o longitudinales que utilicen este test deberían tener en cuenta que cambios en el rendimiento en el test de 2 vueltas podrían deberse a la propia variabilidad de la medida, mientras que cambios de mayor magnitud podrían ser atribuibles a la intervención o cambios asociados a la edad (AU)

Cardiorespiratory fitness is a strong indicator of present and future health in children and adolescents, however it is unknown whether it is for pre-schoolers, from 3 to 5 years. In the present study, we described the adaptation of the original 20m shuttle run test, it feasibility and acceptance in children from 3 to 5 years and its maximality and reliability. A total of 130 students (4.91 ± 0.89 years; 77 boys) performed the test twice, two weeks apart. The test adaptation consisted mainly in reducing the initial speed of 8.5 km/h to 6.5 km/h. The test was feasible and was well accepted in both boys and girls and the three age groups, 3, 4 and 5 years. The maximum heart rate (MHR) achieved for the entire sample was 199.4 ± 12.5 beats/min, equivalent to 97% of the estimated theoretical MHR, and no significant differences by gender or age. Mean test-retest difference (systematic error) in the number of laps achieved was 2 laps, with no significant differences between sex or age. There was no evidence of heteroscedasticity. Our results suggest the test is maximum and reliable in this age group. Future longitudinal or intervention studies using this test should take into account that changes in the test performance of 2 laps may be due to the variability of the measure, while wider changes would be attributable to the intervention or changes associated with age (AU)