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Association between adipose tissue characteristics and metabolic flexibility in humans: A systematic review
(Frontiers Media S.A., 2021-12-03) Glaves, Alice; Díaz-Castro, Francisco; Farías, Javiera; Ramírez-Romero, Rodrigo; Galgan, Jose E.; Fernández-Verdejo, Rodrigo
Adipose tissue total amount, distribution, and phenotype influence metabolic health. This may be partially mediated by the metabolic effects that these adipose tissue characteristics exert on the nearby and distant tissues. Thus, adipose tissue may influence the capacity of cells, tissues, and the organism to adapt fuel oxidation to fuel availability, i.e., their metabolic flexibility (MetF). Our aim was to systematically review the evidence for an association between adipose tissue characteristics and MetF in response to metabolic challenges in human adults. We searched in PubMed (last search on September 4, 2021) for reports that measured adipose tissue characteristics (total amount, distribution, and phenotype) and MetF in response to metabolic challenges (as a change in respiratory quotient) in humans aged 18 to <65 years. Any study design was considered, and the risk of bias was assessed with a checklist for randomized and non-randomized studies. From 880 records identified, 22 remained for the analysis, 10 of them measured MetF in response to glucose plus insulin stimulation, nine in response to dietary challenges, and four in response to other challenges. Our main findings were that: (a) MetF to glucose plus insulin stimulation seems inversely associated with adipose tissue total amount, waist circumference, and visceral adipose tissue; and (b) MetF to dietary challenges does not seem associated with adipose tissue total amount or distribution. In conclusion, evidence suggests that adipose tissue may directly or indirectly influence MetF to glucose plus insulin stimulation, an effect probably explained by skeletal muscle insulin sensitivity
Effect of supervised resistance training on arm volume, quality of life and physical perfomance among women at high risk for breast cancer-related Lymphedema: A study protocol for a randomized controlled Trial (STRONG-B)
(Frontiers Media S.A., 2022-03) Ramírez-Parada, Karol; Lopez-Garzon, Maria; Sanchez-Rojel, Cesar; Petric-Guajardo, Militza; Alfaro-Barra, Margarita; Fernández-Verdejo, Rodrigo; Reyes-Ponce, Alvaro; Merino-Pereira, Gina; Cantarero-Villanueva, Irene
Objectives: To determine the preventive effects of supervised resistance training on arms volume, quality of life, physical performance, and handgrip strength in Chilean women at high risk for breast cancer-related lymphedema (BCRL) undergoing chemotherapy. Design: Randomized control trial. Participants: One hundred and six women at high risk for breast cancer-related lymphedema aged 18 to 70 years. Interventions: Participants will be randomized into two groups: [a] intervention, who will receive 12 weeks of supervised resistance training (STRONG-B) during adjuvant chemotherapy; and [b] control, who will receive education to promote lymphatic and venous return, maintain range of motion, and promote physical activity. Main Outcome Measures: The primary outcome will be arms volume measured with an optoelectric device (perometer NT1000). Secondary outcomes will be quality of life, handgrip strength, and physical performance. Primary and secondary outcomes will be measured at baseline, just after the intervention, and 3 and 6 months after. Statistical analysis will be performed following intention-to-treat and per-protocol approaches. The treatment effect will be calculated using linear mixed models. Discussion: The STRONG-B will be a tailored supervised resistance training that attempts to prevent or mitigate BCRL in a population that, due to both intrinsic and extrinsic factors, will commonly suffer from BCRL.
Effects of ketone bodies on energy expenditure, substrate utilization, and energy intake in humans
(American Society for Biochemistry and Molecular Biology, 2023-09-11) Fernández-Verdejo, Rodrigo; Mey, Jacob T.; Ravussin, Eric
Recientemente se ha prestado atención al potencial de los enfoques cetogénicos para regular el equilibrio energético, ya que las cetonas pueden influir tanto en el gasto como en la ingesta de energía. En esta revisión narrativa, resumimos la evidencia más relevante sobre el papel de la cetosis en el gasto de energía, la utilización de sustratos y la ingesta de energía en humanos. Consideramos diferentes estrategias para inducir la cetosis, como el ayuno, la manipulación dietética y las fuentes exógenas de cetonas. En general, la cetosis no tiene una influencia importante en el gasto energético, pero promueve un cambio en la utilización del sustrato hacia la oxidación de los cuerpos cetónicos. Las estrategias para inducir la cetosis mediante la reducción de la disponibilidad de carbohidratos en la dieta (p. ej., dietas cetogénicas) no influyen de forma independiente en la ingesta de energía, por lo que son igualmente efectivas para perder peso que las dietas con mayor contenido de carbohidratos. Por el contrario, la ingesta de triglicéridos de cadena media y ésteres de cetonas induce cetosis y parece aumentar el gasto energético y reducir la ingesta energética en el contexto de una alta disponibilidad de carbohidratos. Estas últimas estrategias conducen a una pérdida de peso ligeramente mayor. Desafortunadamente, distinguir los efectos de las diversas estrategias cetogénicasper se de los efectos de otras respuestas fisiológicas no es posible con los datos humanos disponibles. Se necesitan estudios hospitalarios altamente controlados que utilicen estrategias específicas para aislar los efectos independientes de las cetonas para abordar adecuadamente esta brecha de conocimiento.
Effects of school closure on lifestyle behaviours and health outcomes in children during the COVID-19 pandemic in Chile: A time-matched analysis
(Wiley; World Obesity Federation, 2024-10-08) Suárez-Reyes, Mónica; Fernández-Verdejo, Rodrigo; Quintiliano, Daiana; Pinheiro, Anna Cristina; Pizarro, Tito
Background The COVID-19 pandemic led to school closures, potentially impairing children's behaviours and health. We aimed to explore the effects of school closure on lifestyle behaviours (dietary habits, physical activity) and health outcomes (adiposity, fitness, self-esteem, self-concept) in children. Methods We measured 247 children before school closure (October–November 2019) and after school reopening (October–November 2021) (COVID-19 group). To distinguish the changes due to school closure from changes due to growth, we included 655 age-matched children with cross-sectional measurements in October–November 2019 (control group). The response of this group (i.e., differences between children with 2 years of difference) was considered the expected response to growth. Two-way ANOVA was used to test age-by-group interactions, indicating an effect of school closure. Results In 7-to-9-year-old children, the COVID-19 group had larger-than-expected decreases in physical activity (by 0.4 points), resulting in higher physical inactivity prevalence (by 19 percent points) at 9 years. This was accompanied by larger-than-expected increases in fat percentage (by 6.1 percent point). In 8-to-10-year-old children, the COVID-19 group had higher physical inactivity prevalence at 10 years (by 20 percent points). This was accompanied by larger-than-expected increases in fat percentage (by 8.3 percent points), z-score BMI (by 0.90 units), and waist circumference (by 6.1 cm). In 9-to-11-year-old children, the COVID-19 group had larger-than-expected decreases in physical activity (by 0.3 points) and increases in self-concept (by 0.2 points). The response in dietary habits, fitness, or self-esteem was not different between groups. Conclusion Overall, school closure negatively impacted physical activity and adiposity, particularly in the youngest children.
Elevated Risk of Overweight/Obesity-Related Markers and Low Muscular Fitness in Children Attending Public Schools in Chile
(MDPI, 2022) Suárez-Reyes, Mónica; Fernández-Verdejo, Rodrigo
In Chile, children of low socioeconomic status usually attend public schools and have few opportunities to engage in healthy behaviors. This may increase their risk of overweight/obesity and low muscular fitness. Therefore, we aimed to determine the association between the school type attended with overweight/obesity-related markers and the muscular fitness of children in Chile. We included 1410 children (6–13 years old) attending public, subsidized, or private schools. Overweight/obesity-related markers included BMI Z-scores, waist circumference, and body fat percentage. Muscular fitness assessment included handgrip strength and standing long jump. The odds ratios [95% CI] of overweight/obesity, elevated waist circumference, elevated body fat, low handgrip strength, and low standing long jump were compared between school types. Compared with boys attending public schools, those attending subsidized or private schools had lower odds ratios of low handgrip strength (0.63 [0.42–0.94] and 0.44 [0.25–0.78], respectively). Girls attending subsidized schools, compared with those in public schools, had lower odds of overweight/obesity (0.63 [0.44–0.90]) and of having low handgrip strength (0.51 [0.34–0.78]). Compared with girls in public schools, those attending private schools had lower odds (vs. public schools) of overweight/obesity (0.45 [0.28–0.74]), of having elevated body fat (0.53 [0.29–0.96]), and of having low standing long jump (0.41 [0.21–0.77]). The elevated risk of overweight/obesity-related markers and lower muscular fitness in children, particularly girls, attending public schools increase their current and future disease risk. This suggests that childhood socioeconomic status plays a central role in determining disease risk. Health-promoting interventions specifically focused on children from disadvantaged contexts are required.
Energy expenditure in humans: principles, methods, and changes throughout the life course
(Annual Reviews Inc., 2024-05-17) Fernández-Verdejo, Rodrigo
Humans require energy to sustain their daily activities throughout their lives. This narrative review aims to (a) summarize principles and methods for studying human energy expenditure, (b) discuss the main determinants of energy expenditure, and (c) discuss the changes in energy expenditure throughout the human life course. Total daily energy expenditure is mainly composed of resting energy expenditure, physical activity energy expenditure, and the thermic effect of food. Total daily energy expenditure and its components are estimated using variations of the indirect calorimetry method. The relative contributions of organs and tissues determine the energy expenditure under different physiological conditions. Evidence shows that energy expenditure varies along the human life course, at least in part due to changes in body composition, the mass and specific metabolic rate of organs and tissues, and levels of physical activity. This information is crucial to estimate human energy requirements for maintaining health throughout the life course.
Exploring the sequential accumulation of metabolic syndrome components in adults
(Springer Nature, 2022) Fernández-Verdejo, Rodrigo; Galgani, Jose E.
The metabolic syndrome (MetS) is diagnosed upon the manifestation of ≥ 3 out of 5 specific components, regardless of their combination. The sequence through which these components accumulate may serve to identify underlying pathophysiological mechanisms and improve MetS treatment. We aimed to explore whether there is a more frequent sequence of accumulation of components in adults. The cross-sectional data of the National Health Survey of Chile 2016–2017 was analyzed. Subjects aged 18 to < 65 years, with body mass index ≥ 18.5 kg/m2, having all MetS components measured, and not under drug treatment were included (n = 1944, 60% women). MetS components were operationalized based on harmonized criteria: elevated waist circumference (≥ 91 cm for men, ≥ 83 cm for women), reduced high-density lipoprotein cholesterol (HDL-C; < 40 mg/dL for men, < 50 mg/dL for women), elevated triglycerides (≥ 150 mg/dL), elevated blood pressure (≥ 130 mmHg for systolic, or ≥ 85 mmHg for diastolic), and elevated glycemia (≥ 100 mg/dL). Subjects were grouped according to the number of components. Then, the prevalence of the observed combinations was determined. In subjects with one component, the most prevalent was waist circumference (56.7%). In subjects with two, the most prevalent combination was waist circumference and HDL-C (50.8%), while in subjects with three components was waist circumference, HDL-C, and triglycerides (54.0%). Finally, in subjects with four, the most prevalent combination was waist circumference, HDL-C, triglycerides, and blood pressure (40.8%). This pattern suggests that the most frequent accumulation sequence starts with abdominal obesity, followed by dyslipidemia, elevated blood pressure, and ultimately, dysglycemia. The factors that determine the sequence remain to be determined.
The fasting-feeding metabolic transition regulates mitochondrial dynamics
(Federation of American Society of Experimental Biology (FASEB), 2021-10-10) Castro-Sepulveda, Mauricio; Morio, Béatrice; Tuñón-Suárez, Mauro; Jannas-Vela, Sebastian; Díaz-Castro, Francisco; Rieusset, Jennifer; Zbinden-Foncea, Hermann
In humans, insulin resistance has been linked to an impaired metabolic transition from fasting to feeding (metabolic flexibility; MetFlex). Previous studies suggest that mitochondrial dynamics response is a putative determinant of MetFlex; however, this has not been studied in humans. Thus, the aim of this study was to investigate the mitochondrial dynamics response in the metabolic transition from fasting to feeding in human peripheral blood mononuclear cells (PBMCs). Six male subjects fasted for 16 h (fasting), immediately after which they consumed a 75-g oral glucose load (glucose). In both fasting and glucose conditions, blood samples were taken to obtain PBMCs. Mitochondrial dynamics were assessed by electron microscopy images. We exposed in vitro acetoacetate-treated PBMCs to the specific IP3R inhibitor Xestospongin B (XeB) to reduce IP3R-mediated mitochondrial Ca2+ accumulation. This allowed us to evaluate the role of ER-mitochondria Ca2+ exchange in the mitochondrial dynamic response to substrate availability. To determine whether PBMCs could be used in obesity context (low MetFlex), we measured mitochondrial dynamics in mouse spleen-derived lymphocytes from WT and ob/ob mice. We demonstrated that the transition from fasting to feeding reduces mitochondria-ER interactions, induces mitochondrial fission and reduces mitochondrial cristae density in human PBMCs. In addition, we demonstrated that IP3R activity is key in the mitochondrial dynamics response when PBMCs are treated with a fasting-substrate in vitro. In murine mononuclear-cells, we confirmed that mitochondria-ER interactions are regulated in the fasted-fed transition and we further highlight mitochondria-ER miscommunication in PBMCs of diabetic mice. In conclusion, our results demonstrate that the fasting/feeding transition reduces mitochondria-ER interactions, induces mitochondrial fission and reduces mitochondrial cristae density in human PBMCs, and that IP3R activity may potentially play a central role.
Fibro-adipogenic progenitors in physiological adipogenesis and intermuscular adipose tissue remodeling
(Elsevier; International Union of Biochemistry and Molecular Biology, 2024-06) Flores-Opazo, Marcelo; Kopinke, Daniel; Helmbacher, Françoise; Fernández-Verdejo, Rodrigo; Tuñón-Suárez, Mauro; Lynch, Gordon S.; Contreras, Osvaldo
Excessive accumulation of intermuscular adipose tissue (IMAT) is a common pathological feature in various metabolic and health conditions and can cause muscle atrophy, reduced function, inflammation, insulin resistance, cardiovascular issues, and unhealthy aging. Although IMAT results from fat accumulation in muscle, the mechanisms underlying its onset, development, cellular components, and functions remain unclear. IMAT levels are influenced by several factors, such as changes in the tissue environment, muscle type and origin, extent and duration of trauma, and persistent activation of fibro-adipogenic progenitors (FAPs). FAPs are a diverse and transcriptionally heterogeneous population of stromal cells essential for tissue maintenance, neuromuscular stability, and tissue regeneration. However, in cases of chronic inflammation and pathological conditions, FAPs expand and differentiate into adipocytes, resulting in the development of abnormal and ectopic IMAT. This review discusses the role of FAPs in adipogenesis and how they remodel IMAT. It highlights evidence supporting FAPs and FAP-derived adipocytes as constituents of IMAT, emphasizing their significance in adipose tissue maintenance and development, as well as their involvement in metabolic disorders, chronic pathologies and diseases. We also investigated the intricate molecular pathways and cell interactions governing FAP behavior, adipogenesis, and IMAT accumulation in chronic diseases and muscle deconditioning. Finally, we hypothesize that impaired cellular metabolic flexibility in dysfunctional muscles impacts FAPs, leading to IMAT. A deeper understanding of the biology of IMAT accumulation and the mechanisms regulating FAP behavior and fate are essential for the development of new therapeutic strategies for several debilitating conditions.
Gaps between the indication and the home execution of massage therapy in children in the postsurgical stage of primary cheiloplasty or rhinocheiloplasty
(Mutaz B. Habal, 2023-09) Montero-Orellana, María José; Fuentes-Orellana, María Rosa; Ossa-Cox, Matías
Purpose: This study describes the compliance rate with home massage therapy in children in the postsurgical stage of primary cheiloplasty or rhinocheiloplasty and the factors that facilitate or hinder its execution. Methods: The parents of 15 children treated at the Gantz Foundation - Children’s hospital for cleft lip and palate in Santiago, Chile were recruited. Parents received instructions to perform massages at home 5 times daily and were followed up for 3 months by recording in a log. Qualitative information on facilitators and barriers was collected in a focus group session. Results: Compliance rate was close to 75%, and the factors that facilitated the execution were performing the massage with some distracting activity and noticing the positive changes in the appearance of the scars. The most important factors that hindered the execution were the infant’s crying and changes in the routine. Conclusion: The authors conclude that the compliance rate is high and suggest that parents and guardians identify and implement a routine with a distracting activity that allows the massage to be carried out effectively.
Gasto energético en reposo y concentración sérica de lipoproteínas de baja densidad en adultos con hipotiroidismo subclínico leve
(Sociedad Chilena de Nutrición, Bromatología y Toxicología, 2024-04-01) Fernández-Verdejo, Rodrigo
La alta prevalencia de hipotiroidismo subclínico en Chile puede deberse a que el límite superior normal de la hormona estimulante del tiroides (TSH) sérica es bajo. Personas con TSH levemente mayor al límite superior pueden ser metabólicamente similares a personas sanas. Se compararon marcadores de acción tiroidea (gasto energético en reposo [GER] y lipoproteína de baja densidad [LDL]) en adultos con hipotiroidismo subclínico leve y con función tiroidea normal con o sin tratamiento con levotiroxina. Se midió GER, perfil lipídico y tiroideo en personas sanas con función tiroidea normal (TSH ≥0,4-<4,5 µUI/ml; n=91); con hipotiroidismo subclínico leve (TSH ≥4,5-≤6,5 µUI/ml; n=5); y con hipotiroidismo clínico tratado con levotiroxina y TSH normal (n=13). Se analizó la LDL en 838 personas sanas con función tiroidea normal y 89 con hipotiroidismo subclínico leve de la Encuesta Nacional de Salud 2016/17 (ENS). El GER, ajustado por peso, sexo y edad, fue similar entre grupos (p=0,71). La LDL fue similar entre personas con función tiroidea normal e hipotiroidismo subclínico leve (91±24 vs. 101±17 mg/dl; p=0,67), y menor en hipotiroidismo tratado (64±22 mg/dl; p<0,01). La LDL no se asoció con TSH pero si inversamente con T4L en mujeres (r=-0,33; p=0,02; n=53). En la ENS, ambos grupos tuvieron similar LDL (p=0,34), la que se asoció inversamente con T4L en mujeres (r=-0,12; p=0,01; n=569) pero no con TSH. Personas sanas con función tiroidea normal y con hipotiroidismo subclínico leve tienen similar GER y LDL. Esto apoya la idea de redefinir el límite superior normal de TSH.
Low abundance of Mfn2 protein correlates with reduced mitochondria-SR juxtaposition and mitochondrial cristae density in human men skeletal muscle: Examining organelle measurements from TEM images
(Wiley Open Access, 2021-03-08) Castro-Sepulveda, Mauricio; Fernández-Verdejo, Rodrigo; Tuñón-Suárez, Mauro; Morales-Zúñiga, Jorge; Troncoso, Mayarling; Jannas-Vela, Sebastian; Zbinden-Foncea, Hermann
The role of mitofusin 2 (Mfn2) in the regulation of skeletal muscle (SM) mitochondria-sarcoplasmic (SR) juxtaposition, mitochondrial morphology, mitochondrial cristae density (MCD), and SM quality has not been studied in humans. In in vitro studies, whether Mfn2 increases or decreases mitochondria-SR juxtaposition remains controversial. Transmission electron microscopy (TEM) images are commonly used to measure the organelle juxtaposition, but the measurements are performed "by-hand," thus potentially leading to between-rater differences. The purposes of this study were to: (1) examine the repeatability and reproducibility of mitochondrial-SR juxtaposition measurement from TEM images of human SM between three raters with different experience and (2) compare the mitochondrial-SR juxtaposition, mitochondrial morphology, MCD (stereological-method), and SM quality (cross-sectional area [CSA] and the maximum voluntary contraction [MVC]) between subjects with high abundance (Mfn2-HA; n = 6) and low abundance (Mfn2-LA; n = 6) of Mfn2 protein. The mitochondria-SR juxtaposition had moderate repeatability and reproducibility, with the most experienced raters showing the best values. There were no differences between Mfn2-HA and Mfn2-LA groups in mitochondrial size, distance from mitochondria to SR, CSA, or MVC. Nevertheless, the Mfn2-LA group showed lower mitochondria-SR interaction, MCD, and VO2max . In conclusion, mitochondrial-SR juxtaposition measurement depends on the experience of the rater, and Mfn2 protein seems to play a role in the metabolic control of human men SM, by regulating the mitochondria-SR interaction.
Metabolic elasticity — a new trait associated with health?
(Nature Publishing Group, 2023-10-13) Fernández-Verdejo, Rodrigo; Galgani, Jose E.
A recent study by Zhou and colleagues proposed that low metabolic elasticity and gene elasticity are involved in the metabolic alterations observed in ageing and obesity. Here, we discuss some of their findings to provide a viewpoint on these potential new traits associated with metabolic health.
Microencapsulated pomegranate peel extract induces mitochondrial complex IV activity and prevents mitochondrial cristae alteration in brown adipose tissue in mice fed on a high-fat diet
(Cambridge University Press, 2021-09-28) Echeverria, Francisca; Jimenez Patino, Paula; Castro-Sepulveda, Mauricio; Bustamante, Andres; Garcia Concha, Paula; Poblete-Aro, Carlos; Valenzuela, Rodrigo; Garcia-Diaz, Diego F.
Pomegranate peel is an agro-industrial residue obtained after fruit processing with high total polyphenol (TP) content, making it an attractive by-product for its reuse. Pomegranate peel extract (PPE) and its bioactive compounds have shown positive effects on obesity models. Effects on favouring mitochondrial biogenesis and function have also been described. However, once phenolic compounds are extracted, their stability can be affected by diverse factors. Microencapsulation could improve PPE stability, allowing its incorporation into functional foods. Nevertheless, studies on the potential biological effects of PPE microparticles (MPPE) in obesity models are lacking. This study aims to evaluate the effect of MPPE on brown adipose tissue (BAT) mitochondrial structure and function and metabolic alterations related to obesity in mice fed a high-fat diet (HFD). PPE was microencapsulated by spray drying using inulin (IN) as a wall material and physically-chemically characterised. Eight-week-old male C57BL/6J mice (n 40) were randomly distributed into five groups: control diet (CD), HFD, HFD + IN, HFD + PPE (50 mg/kg per d TP) and HFD + MPPE (50 mg/kg per d TP), for 14 weeks. A glucose tolerance test and indirect calorimetry were conducted. Blood and adipose tissue samples were obtained. MPPE supplementation prevented HFD-induced body weight gain (P < 0·001), fasting glycaemia (P = 0·007) and total cholesterol rise (P = 0·001). MPPE resulted in higher BAT mitochondrial complex IV activity (P = 0·03) and prevented HFD-induced mitochondrial cristae alteration (P = 0·02). In conclusion, MPPE prevented HFD-induced excessive body weight gain and associated metabolic disturbances, potentially by activating complex IV activity and preserving mitochondrial cristae structure in BAT in mice fed with a HFD.
A mutation in desmin makes skeletal muscle less vulnerable to acute muscle damage after eccentric loading in rats
(Wiley; Federation of American Societies for Experimental Biology, 2021-09-01) Langer, Henning T.; Mossakowski, Agata A.; Avey, Alec M.; Wohlgemuth, Ross P.; Smith, Lucas R.; Zbinden-Foncea, Herman; Baar, Keith
Desminopathy is the most common intermediate filament disease in humans. The most frequent mutation causing desminopathy in patients is a R350P DES missense mutation. We have developed a rat model with an analogous mutation in R349P Des. To investigate the role of R349P Des in mechanical loading, we stimulated the sciatic nerve of wild-type littermates (WT) (n = 6) and animals carrying the mutation (MUT) (n = 6) causing a lengthening contraction of the dorsi flexor muscles. MUT animals showed signs of ongoing regeneration at baseline as indicated by a higher number of central nuclei (genotype: P < .0001). While stimulation did not impact central nuclei, we found an increased number of IgG positive fibers (membrane damage indicator) after eccentric contractions with both genotypes (stimulation: P < .01). Interestingly, WT animals displayed a more pronounced increase in IgG positive fibers with stimulation compared to MUT (interaction: P < .05). In addition to altered histology, molecular signaling on the protein level differed between WT and MUT. The membrane repair protein dysferlin decreased with eccentric loading in WT but increased in MUT (interaction: P < .05). The autophagic substrate p62 was increased in both genotypes with loading (stimulation: P < .05) but tended to be more elevated in WT (interaction: P = .05). Caspase 3 levels, a central regulator of apoptotic cell death, was increased with stimulation in both genotypes (stimulation: P < .01) but more so in WT animals (interaction: P < .0001). Overall, our data indicate that R349P Des rats have a lower susceptibility to structural muscle damage of the cytoskeleton and sarcolemma with acute eccentric loading.
¿Los niveles de Testosterona y Cortisol influyen en el rendimiento en el rugby?: una mirada al rugby sevens
(Sociedad Chilena de Medicina del Deporte, 2022-04-30) Zúñiga-Vergara., Pedro; Castro-Sepulveda, Mauricio
Resumen: Introducción: El Rugby 7 (R7) es una rama del Rugby Unión (RU) y se caracteriza principalmente por ser un deporte de oposición con períodos de juego intensos y de corta duración, por lo tanto, los componentes psicológicos y fisiológicos juegan un rol en el rendimiento. En el R7, los deportistas compiten varias veces durante un mismo día, permitiendo la acumulación de fatiga. Esta acumulación de fatiga se puede explicar principalmente por la intensidad del juego y el número de colisiones a alta intensidad provocando perturbaciones a nivel muscular, endocrino y del sistema inmune. Sin embargo, a la fecha no existen trabajos que integren las respuestas fisiológicas como, por ejemplo, las respuestas hormonales de los jugadores a dichas demandas. Objetivo: Realizar una revisión de la literatura científica en relación al efecto de las hormonas T, C y el Ratio T/C en el rendimiento deportivo en el R7. Metodología: Revisión narrativa de la literatuta, se realizó una búsqueda durante los meses de abril a noviembre del 2021 en 4 bases de datos (Pubmed/Medline, Google Scholar, Scopus (Elsevier) y Scielo). Después de analizar 335 textos se consideró su utilidad y relevacia para la inclusión a esta revisión. 11 Estudios cumplierón con los criterios de inclusión. Resultados: Los trabajos incluidos asocián la relación hormonal con el rendimiento deportivo en el RU y R7. Se destaca la relación grande (r=0,80) de la T con el rendimiento deportivo en el RU. Conclusión: Según los estudios analizados se puede observar
Postural and lumbopelvic control: crucial factors in the functionality of patients with low back pain—a descriptive cross-sectional study
(MDPI, 2024-07-29) Stöwhas Villarroel, Katherine; Droppelmann Díaz Guillermo; Jorquera, Carlos; Feijoo, Felipe
Low back pain (LBP) is one of the most prevalent musculoskeletal disorders in adults worldwide. Alterations in postural and lumbopelvic control and functionality appear to be determining factors in its resolution. Methods: A cross-sectional study was performed. Patients with LBP were enrolled. Lumbar pain; postural control (PC), total area of the center of pressure (TACOP), and the velocity of the center of pressure (VCOP); lumbopelvic control (LPC); and functionality were evaluated. Statistical tests were implemented to determine differences between sex and age and correlation models among the variables. Results: Thirty adult patients with LBP were analyzed. A strong relationship was found between pain and functionality [r = 0.64; p < 0.001]. A moderate relationship was found between pain and TACOP [r = 0.395; p = 0.031]. A moderate relationship was observed between TACOP and functionality [0.413; p = 0.023] and between LPC and TACOP [r = 0.416; p = 0.001]. Conclusions: This study demonstrates the significant impact of LBP on postural control, lumbopelvic control, and functionality. These results highlight the importance of addressing postural and lumbopelvic control in LBP treatment. No significant differences based on gender and age were found, but all clinical variables differed significantly between the LBP and control groups, underscoring the unique impairments associated with LBP.
Predictive equations for energy expenditure in adult humans: From resting to free-living conditions
(Wiley; The Obesity Society, 2022-07-19) Fernández-Verdejo, Rodrigo; Galgani, José E.
Humans acquire energy from the environment for survival. A central question for nutritional sciences is how much energy is required to sustain cellular work while maintaining an adequate body mass. Because human energy balance is not exempt from thermodynamic principles, the energy requirement can be approached from the energy expenditure. Conceptual and technological advances have allowed understanding of the physiological determinants of energy expenditure. Body mass, sex, and age are the main factors determining energy expenditure. These factors constitute the basis for predictive equations for resting (REE) and total (TEE) energy expenditure in healthy adults. These equations yield predictions that differ up to ~400 kcal/d for REE and ~550 kcal/d for TEE. Identifying additional factors accounting for such variability and the most valid equations appears relevant. This review used novel approaches based on mathematical modeling of REE and analyses of the data from which REE predictive equations were generated. As for TEE, R2 and SE were considered because only a few predictive equations are available. From these analyses, Oxford's and Plucker's equations appear valid for predicting REE and TEE in adults, respectively.
Prevalence of non-alcoholic fatty liver disease and its association with lifestyle habits in adults in Chile: a cross-sectional study from the National Health Survey 2016-2017
(Cambridge University Press, 2023-01) Fernández-Verdejo, Rodrigo
Non-alcoholic fatty liver disease (NAFLD) represents an excessive fat accumulation within the liver, usually associated with excess body weight. A liver biopsy is the gold standard for diagnosis, but it is inapplicable in population-based studies. In large populations, non-invasive methods could be used, which may also serve to identify potential protective factors. We aimed to: [a] estimate NAFLD prevalence in the adult population in Chile by using non-invasive methods; and [b] determine the association between the presence of NAFLD and lifestyle habits. The National Health Survey of Chile 2016-2017 was analysed. We included individuals aged 21-75 years, without infectious diseases nor risky alcohol consumption. NAFLD was detected by either Fatty Liver Index (FLI; considers circulating triglycerides, circulating gamma-glutamyl-transferase, body mass index, and waist circumference), Lipid Accumulation Product (LAP; considers sex, circulating triglycerides, and waist circumference), or their combination. Lifestyle habits were determined by questionnaires. We included 2,774 participants, representative of 10,599,094 [9,831,644-11,366,544] adults in Chile. NAFLD prevalence [95%CI] was 39.4% [36.2-42.8] by FLI, 27.2% [24.2-30.4] by LAP, and 23.5% [20.7-26.5] by their combination. The prevalence progressively increased with increasing body mass index. Less smoking, and more moderate-vigorous physical activity and whole-grain consumption were associated with lower odds of having NAFLD, independently of body mass index. At least one out of four adults in Chile is afflicted with NAFLD. Health promotion strategies focused on controlling excess body weight and promoting specific lifestyle habits are urgently required.
Resting energy metabolism and sweet taste preference during the menstrual cycle in healthy women
(Newcastle University Population Health Sciences Inst, 2023-08-29) Fernández-Verdejo, Rodrigo; Malo-Vintimilla, Lorena; Aguirre, Carolina; Vergara, Angie; Galgani, Jose E.
Differences in blood concentration of sex hormones in the follicular (FP) and luteal (LP) phases may influence energy metabolism in women. We compared fasting energy metabolism and sweet taste preference on a representative day of the FP and LP in twenty healthy women (25·3 (SD 5·1) years, BMI: 22·2 (SD 2·2) kg/m2) with regular self-reported menses and without the use of hormonal contraceptives. From the self-reported duration of the three prior menstrual cycles, the predicted FP and LP visits were scheduled for days 5–12 and 20–25 after menses, respectively. The order of the FP and LP visits was randomly assigned. On each visit, RMR and RQ by indirect calorimetry, sweet taste preference by the Monell two-series forced-choice tracking procedure, serum fibroblast growth factor 21 by a commercial ELISA (FGF21, a liver-derived protein with action in energy balance, fuel oxidation and sugar preference) and dietary food intake by a 24-h dietary recall were determined. Serum progesterone and oestradiol concentrations displayed the expected differences between phases. RMR was lower in the FP v. LP (5042 (SD 460) v.5197 (SD 490) kJ/d, respectively; P = 0·04; Cohen effect size, drm = 0·33), while RQ showed borderline significant higher values (0·84 (SD 0·05) v.0·81 (SD 0·05), respectively; P = 0·07; drm = 0·62). Also, in the FP v. LP, sweet taste preference was lower (12 (SD 8) v. 16 (SD 9) %; P = 0·04;drm = 0·47) concomitant with higher serum FGF21 concentration (294 (SD 164) v. 197 (SD 104) pg/ml; P < 0·01; drm = 0·66). The menstrual cycle is associated with changes in energy expenditure, sweet taste preference and oxidative fuel partitioning.

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