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Estimation of ventilatory thresholds during exercise using respiratory wearable sensors
(Springer Nature, 2024) Contreras-Briceño, Felipe; Cancino, Jorge; Espinoza-Ramírez, Maximiliano; Fernández, Gonzalo; Johnson, Vader; Hurtado, Daniel
Ventilatory thresholds (VTs) are key physiological parameters used to evaluate physical performance and determine aerobic and anaerobic transitions during exercise. Current assessment of these parameters requires ergospirometry, limiting evaluation to laboratory or clinical settings. In this work, we introduce a wearable respiratory system that continuously tracks breathing during exercise and estimates VTs during ramp tests. We validate the respiratory rate and VTs predictions in 17 healthy adults using ergospirometry analysis. In addition, we use the wearable system to evaluate VTs in 107 recreational athletes during ramp tests outside the laboratory and show that the mean population values agree with physiological variables traditionally used to exercise prescription. We envision that respiratory wearables can be useful in determining aerobic and anaerobic parameters with promising applications in health telemonitoring and human performance.
Study protocol and rationale of "the UP project": evaluating the effectiveness of active breaks on health indicators in desk-based workers
(Frontiers Media S.A., 2024) Cristi-Montero, Carlos; Martínez-Flores, Ricardo; Espinoza-Puelles, Juan Pablo; Favero-Ramirez, Laura; Zurita-Corvalan, Natalia; Castillo Cañete, Ignacio; Leppe, Jaime; Ferrari, Gerson; Sadarangani, Kabir P.; Cancino, Jorge; Hernandez-Jaña, Sam; Yuing Farias, Tuillang; Batista Lemes, Vanilson; Rodríguez-Rodríguez, Fernando; Brand, Caroline
Background: Excessive sedentary time has been negatively associated with several health outcomes, and physical activity alone does not seem to fully counteract these consequences. This panorama emphasizes the essential of sedentary time interruption programs. “The Up Project” seeks to assess the effectiveness of two interventions, one incorporating active breaks led by a professional and the other utilizing a computer application (self-led), of both equivalent duration and intensity. These interventions will be compared with a control group to evaluate their impact on physical activity levels, sedentary time, stress perception, occupational pain, and cardiometabolic risk factors among office workers. Methods: This quasi-experimental study includes 60 desk-based workers from universities and educational institutes in Valparaiso, Chile, assigned to three groups: (a) booster breaks led by professionals, (b) computer prompts that are unled, and (c) a control group. The intervention protocol for both experimental groups will last 12 weeks (only weekdays). The following measurements will be performed at baseline and post-intervention: cardiometabolic risk based on body composition (fat mass, fat-free mass, and bone mass evaluated by DXA), waist circumference, blood pressure, resting heart rate, and handgrip strength. Physical activity and sedentary time will be self-reported and device-based assessed using accelerometry. Questionnaires will be used to determine the perception of stress and occupational pain. Discussion: Governments worldwide are addressing health issues associated with sedentary behavior, particularly concerning individuals highly exposed to it, such as desk-based workers. Despite implementing certain strategies, there remains a noticeable gap in comprehensive research comparing diverse protocols. For instance, studies that contrast the outcomes of interventions led by professionals with those prompted by computers are scarce. This ongoing project is expected to contribute to evidence-based interventions targeting reduced perceived stress levels and enhancing desk-based employees’ mental and physical well-being. The implications of these findings could have the capacity to lay the groundwork for future public health initiatives and government-funded programs.
Early exercise through telerehabilitation after bariatric surgery: is it feasible?
(Springer, 2024) Pino Zúñiga, Johanna; Olivares, Mariela; Muñoz, Giselle; Boza, Camilo; Duque, Camilo; Cancino, Jorge
Purpose: The feasibility of early telerehabilitation after bariatric surgery is unknown. The objective of this study was to assess the feasibility and perception of engaging in the online exercise protocol in patients during the first month after bariatric surgery. Material and methods: A total of 67 patients, enrolled in a telerehabilitation program following bariatric surgery, completed a survey assessing their perception of the intensity, discomfort, and safety during exercise sessions. Results: Forty percent of participants began exercising between 5 and 10 days after surgery. Seventy-one percent of patients did not experience discomfort during the first month of exercise, and those who reported discomfort mainly mentioned dizziness and abdominal pain. No significant differences were found in the presence of discomfort among different types of surgeries performed. There was a significant difference in the presence of discomfort between patients who started exercising before and after 15 days of surgery, with less discomfort reported in the group that started after 15 days. Ninety-eight percent of patients felt safe during online exercise sessions. Most participants perceived the intensity of the sessions as moderate. The most frequently mentioned benefits of exercise were increased energy, mood, and feeling more active. Conclusion: Telerehabilitation conducted during the first month after bariatric surgery was feasible and well tolerated by patients, providing a safe alternative for those patients who face difficulties with in-person interventions.
The effects of maca (lepidium meyenii walp) on cellular oxidative stress: a systematic review and meta-analysis
(MDPI, 2024-08-28) Huerta Ojeda, Álvaro; Rodríguez Rojas, Javiera; Cuevas Guíñez, Jorge; Ciriza Velásquez, Stephanie; Cancino, Jorge; Barahona Fuentes, Guillermo; Yeomans Cabrera, María Mercedes; Pavez, Leonardo; Jorquera Aguilera, Carlos
Lepidium meyenii Walp (LmW) or Maca, including its bioactive components such as macamides, among others, has demonstrated antioxidant effects. However, the effect size (ES) of LmW on oxidative stress has not been qualitatively described and calculated. The primary objective of this systematic review and meta-analysis was to review and qualitatively describe the studies published up to 2023 that supplemented LmW to control cellular oxidative stress; the secondary objective was to calculate the ES of the different interventions. The search was designed following the PRISMA® guidelines for systematic reviews and meta-analyses and performed in the Web of Science, Scopus, SPORTDiscus, PubMed, and MEDLINE until 2023. The selection of studies included randomized controlled trials, with tests and post-tests, both in vitro and in vivo in animals and humans. The methodological quality and risk of bias were evaluated with the CAMARADES tool. The main variables were reduced glutathione, glutathione peroxidase, superoxide dismutase, and malondialdehyde. The analysis was conducted with a pooled standardized mean difference (SMD) through Hedges’ g test (95% CI). Eleven studies were included in the systematic review and eight in the meta-analysis. They revealed a small effect for reduced glutathione (SMD = 0.89), a large effect for glutathione peroxidase (SMD = 0.96), a moderate effect for superoxide dismutase (SMD = 0.68), and a moderate effect for malondialdehyde (SMD = −0.53). According to the results, the phytochemical compounds of LmW effectively controlled cellular oxidative stress, mainly macamides. It was also determined that a higher dose of LmW generated a greater antioxidant effect. However, information concerning humans is scarce.
Creatine supplementation prior to strength exercise training is not superior in preventing muscle mass loss compared with standard nutritional recommendations in females after bariatric surgery: a pilot study
(Springer Nature, 2024) Díaz Pizarro, Marcelo; Pino Zúñiga, Johanna; Olivares Gálvez , Mariela; Rendón Vesga , Carolina; Luengas Tello, Rafael; Duque Seguro, Juan Camilo; Cancino, Jorge
Background: This study examines whether creatine supplementation combined with strength training mitigates muscle mass loss in women during early rehabilitation post-bariatric surgery, as its effectiveness remains untested in this context. Methods: Fifteen women (37.8 ± 9.6 years; BMI, 38.8 ± 5.6 kg/m2) completed the intervention (creatine group = 7; placebo group = 8). Both groups followed a strength training program three times a week for 8 weeks. The dosage for both the creatine and placebo was 8 g prior to each exercise session. Body weight, skeletal muscle mass, fat mass, handgrip strength, and physical activity levels were measured before and after the intervention. Results: The creatine group showed a reduction of 9.5 ± 1.5 kg in body weight, with a 0.72 ± 0.6 kg decrease in muscle mass and an 8.64 ± 1.2 kg reduction in fat mass. The placebo group had a reduction of 9.6 ± 3.5 kg in body weight, with a 0.6 ± 1.2 kg decrease in muscle mass and an 8.88 ± 3.2 kg reduction in fat mass, without significant differences between groups (p > 0.05). Conclusion: The pre-session strength exercise training creatine supplementation is not superior to placebo regarding body weight and fat mass losses and the attenuation of muscle mass loss during the first weeks of rehabilitation following bariatric surgery.
A single bout of resistance exercise triggers mitophagy, potentially involving the ejection of mitochondria in human skeletal muscle
(Wiley, 2024-09-24) Díaz-Castro, Francisco; Tuñón-Suárez, Mauro; Rivera, Patricia; Botella, Javier; Cancino, Jorge; Figueroa, Ana María; Gutiérrez, Juan; Cantin, Claudette; Deldicque, Louise; Zbinden-Foncea, Hermann; Nielsen, Joachim; Henríquez-Olguín, Carlos; Morselli, Eugenia; Castro-Sepulveda, Mauricio
Aim The present study aimed to investigate the effects of a single bout of resistance exercise on mitophagy in human skeletal muscle (SkM). Methods Eight healthy men were recruited to complete an acute bout of one-leg resistance exercise. SkM biopsies were obtained one hour after exercise in the resting leg (Rest-leg) and the contracting leg (Ex-leg). Mitophagy was assessed using protein-related abundance, transmission electron microscopy (TEM), and fluorescence microscopy. Results Our results show that acute resistance exercise increased pro-fission protein phosphorylation (DRP1Ser616) and decreased mitophagy markers such as PARKIN and BNIP3L/NIX protein abundance in the Ex-leg. Additionally, mitochondrial complex IV decreased in the Ex-leg when compared to the Rest-leg. In the Ex-leg, TEM and immunofluorescence images showed mitochondrial cristae abnormalities, a mitochondrial fission phenotype, and increased mitophagosome-like structures in both subsarcolemmal and intermyofibrillar mitochondria. We also observed increased mitophagosome-like structures on the subsarcolemmal cleft and mitochondria in the extracellular space of SkM in the Ex-leg. We stimulated human primary myotubes with CCCP, which mimics mitophagy induction in the Ex-leg, and found that BNIP3L/NIX protein abundance decreased independently of lysosomal degradation. Finally, in another human cohort, we found a negative association between BNIP3L/NIX protein abundance with both mitophagosome-like structures and mitochondrial cristae density in the SkM. Conclusion The findings suggest that a single bout of resistance exercise can initiate mitophagy, potentially involving mitochondrial ejection, in human skeletal muscle. BNIP3L/NIX is proposed as a sensitive marker for assessing mitophagy flux in SkM.
BMAL1 and CLOCK proteins exhibit differential association with mitochondrial dynamics, protein synthesis pathways and muscle strength in human muscle
(The Physiological Society, 2024-06-26) Figueroa-Toledo, A. M.; Gutiérrez-Pino, J.; Carriel-Nesvara, A.; Marchese-Bittencourt, M.; Zbinden-Foncea, Hermann; Castro-Sepulveda, Mauricio
Murine models lacking CLOCK/BMAL1 proteins in skeletal muscle (SkM) present muscle deterioration and mitochondria abnormalities. It is unclear whether humans with lower levels of these proteins in the SkM have similar alterations. Here we evaluated the association between BMAL1 and CLOCK protein mass with mitochondrial dynamics parameters and molecular and functional SkM quality markers in males. SkM biopsies were taken from the vastus lateralis of 16 male (non-athletes, non-obese and non-diabetic) subjects (8–9 a.m.). The morphology of mitochondria and their interaction with the sarcoplasmic reticulum (mitochondria-SR) were determined using transmission electron microscopy images. Additionally, protein abundance of the OXPHOS complex, mitochondria fusion/fission regulators, mitophagy and signalling proteins related to muscle protein synthesis were measured. To evaluate the quality of SkM, the cross-sectional area and maximal SkM strength were also measured. The results showed that BMAL1 protein mass was positively associated with mitochondria-SR distance, mitochondria size, mitochondria cristae density and mTOR protein mass. On the other hand, CLOCK protein mass was negatively associated with mitochondria-SR interaction, but positively associated with mitochondria complex III, OPA1 and DRP1 protein mass. Furthermore, CLOCK protein mass was positively associated with the protein synthesis signalling pathway (total mTOR, AKT and P70S6K protein mass) and SkM strength. These findings suggest that the BMAL1 and CLOCK proteins play different roles in regulating mitochondrial dynamics and SkM function in males, and that modulation of these proteins could be a potential therapeutic target for treating muscle diseases.
Detraining’s effects on cardiorespiratory fitness and maximal and explosive strength in army soldiers: does age matter?
(MDPI, 2024-07-01) Arce-Álvarez, Alexis; Zaio, Ángelo; Salazar-Ardiles, Camila; Álvarez, Cristian; Merino-Muñoz, Pablo; Vasquez-Muñoz, Manuel; Izquierdo, Mikel; Castro-Sepulveda, Mauricio; Andrade, David C.
Purpose: This study investigated the impact of four weeks of age-dependent detraining on army soldiers’ cardiorespiratory fitness and maximal and explosive strength. Methods: Fourteen volunteer tactical athletes participated, divided into two age groups (20 to 29 and 30 to 40 years). Before and after the detraining period, we assessed their anthropometric measurements (weight, height, body mass index, fat mass, and fat-free mass), cardiorespiratory fitness (maximal oxygen uptake [VO2max] and ventilatory thresholds [VT1 and VT2]), and kinematic properties during a single-leg counter-moving jump (CMJ) test for both the dominant and non-dominant legs. Two-way ANOVA followed by the Holm–Sidak post hoc test was used. Results: The anthropometric and cardiovascular variables did not show significant differences between the groups. However, both groups exhibited a significantly reduced maximum time and speed at the VO2max. Furthermore, the flight time and maximum height during the CMJ significantly decreased in the non-dominant leg for both age groups. Notably, the dominant leg’s concentric impulse (CI) significantly reduced during the CMJ, but this effect was observed only in the 30–40 age group. There were significant differences between the two age groups. Conclusions: Our findings suggest that four weeks of detraining negatively impacts aerobic fitness and muscular strength, independently of age. However, the dominant leg may be more susceptible to detraining effects in army soldiers aged 30–40. Furthermore, as a perspective, our results strongly suggest that a detraining period could affect successful missions (aerobic performance deterioration), as well as promote a muscle imbalance between the legs, which could encourage muscle injuries and endanger combat missions.
Effects of an antioxidants cocktail on glucose metabolism at rest, during exercise, and during a glucose load in healthy young subjects
(Sociedad Chilena de Nutrición, Bromatología y Toxicología, 2023-12-15) Rodríguez, Ivan; Paez Espinosa, Enma Verónica; Zbinden-Foncea, Hermann; Echeverria, Francisca; Castro-Sepulveda, Mauricio
Background: Reactive oxygen species (ROS) regulate glucose metabolism (GM) in skeletal muscle by improving the translocation of GLUT4. Antioxidant supplementation could block this physiological effect, altering glucose signaling during exercise. However, there is limited evidence in humans on whether antioxidant intake affects GM. Therefore, we aimed to determine the effect of an antioxidant cocktail (AOC) on GM at rest and during metabolic challenges. Methods: Ten healthy male subjects received AOC supplementation (1000 mg of Vitamin C, 600 IU of Vitamin E, and 600 mg of α-lipoic acid) or placebo (2.000 mg of talc) before two trials conducted 7 days apart. Trial 1: AOC 120 and 90 minutes before an endurance exercise (EEX) bout at 60 % of maximal oxygen uptake (VO2max); Trial 2: AOC 120 and 90 minutes before an oral glucose tolerance test (OGTT; 75 g glucose). Measurements of gas exchange and capillary blood samples were collected every 15 minutes during both trials. Results: AOC supplementation increased resting glucose levels (p<0.05). During Trial 1 (EEX), the AOC increased carbohydrate oxidation (CHOox) (p= 0.03), without effect in glucose blood levels. During Trial 2 (OGTT), the AOC supplementation had no significant effect on GM parameters. Conclusion: Acute supplementation with AOC increased resting glucose levels and CHOox during EEX in healthy subjects, with no effect on GM during the OGTT.
Regulation of mitochondrial morphology and cristae architecture by the TLR4 pathway in human skeletal muscle
(Frontiers Media S.A., 2023-06-25) Castro-Sepulveda, Mauricio; Tuñón-Suárez, Mauro; Rosales-Soto, Giovanni; Vargas-Foitzick, Ronald; Deldicque, Louise; Zbinden-Foncea, Hermann
In skeletal muscle (SkM), a reduced mitochondrial elongate phenotype is associated with several metabolic disorders like type 2 diabetes mellitus (T2DM). However, the mechanisms contributing to this reduction in mitochondrial elongate phenotype in SkM have not been fully elucidated. It has recently been shown in a SkM cell line that toll-like receptor 4 (TLR4) contributes to the regulation of mitochondrial morphology. However, this has not been investigated in human SkM. Here we found that in human SkM biopsies, TLR4 protein correlated negatively with Opa1 (pro-mitochondrial fusion protein). Moreover, the incubation of human myotubes with LPS reduced mitochondrial size and elongation and induced abnormal mitochondrial cristae, which was prevented with the co-incubation of LPS with TAK242. Finally, T2DM myotubes were found to have reduced mitochondrial elongation and mitochondrial cristae density. Mitochondrial morphology, membrane structure, and insulin-stimulated glucose uptake were restored to healthy levels in T2DM myotubes treated with TAK242. In conclusion, mitochondrial morphology and mitochondrial cristae seem to be regulated by the TLR4 pathway in human SkM. Those mitochondrial alterations might potentially contribute to insulin resistance in the SkM of patients with T2DM.
Mitochondria-SR interaction and mitochondrial fusion/fission in the regulation of skeletal muscle metabolism
(Elsevier, 2023-07-01) Castro-Sepulveda, Mauricio; Fernández-Verdejo, Rodrigo; Zbinden-Foncea, Hermann; Rieusset, Jennifer
Mitochondria-endoplasmic/sarcoplasmic reticulum (ER/SR) interaction and mitochondrial fusion/fission are critical processes that influence substrate oxidation. This narrative review summarizes the evidence on the effects of substrate availability on mitochondrial-SR interaction and mitochondria fusion/fission dynamics to modulate substrate oxidation in human skeletal muscle. Evidence shows that an increase in mitochondria-SR interaction and mitochondrial fusion are associated with elevated fatty acid oxidation. In contrast, a decrease in mitochondria-SR interaction and an increase in mitochondrial fission are associated with an elevated glycolytic activity. Based on the evidence reviewed, we postulate two hypotheses for the link between mitochondrial dynamics and insulin resistance in human skeletal muscle. First, glucose and fatty acid availability modifies mitochondria-SR interaction and mitochondrial fusion/fission to help the cell to adapt substrate oxidation appropriately. Individuals with an impaired response to these substrate challenges will accumulate lipid species and develop insulin resistance in skeletal muscle. Second, a chronically elevated substrate availability (e.g. overfeeding) increases mitochondrial production of reactive oxygen species and induced mitochondrial fission. This decreases fatty acid oxidation, thus leading to the accumulation of lipid species and insulin resistance in skeletal muscle. Altogether, we propose mitochondrial dynamics as a potential target for disturbances associated with low fatty acid oxidation.
Ursodeoxycholic acid induces sarcopenia associated with decreased protein synthesis and autophagic flux
(MBC, 2023-05-27) Orozco‐Aguilar, Josué; Franco Tacchi, Franco; Valero‐Breton, Mayalen; Castro-Sepulveda, Mauricio; Simon, Felipe; Cabello‐Verrugio, Claudio
Background Skeletal muscle generates force and movements and maintains posture. Under pathological conditions, muscle fibers suffer an imbalance in protein synthesis/degradation. This event causes muscle mass loss and decreased strength and muscle function, a syndrome known as sarcopenia. Recently, our laboratory described secondary sarcopenia in a chronic cholestatic liver disease (CCLD) mouse model. Interestingly, the administration of ursodeoxycholic acid (UDCA), a hydrophilic bile acid, is an effective therapy for cholestatic hepatic alterations. However, the effect of UDCA on skeletal muscle mass and functionality has never been evaluated, nor the possible involved mechanisms. Methods We assessed the ability of UDCA to generate sarcopenia in C57BL6 mice and develop a sarcopenic-like phenotype in C2C12 myotubes and isolated muscle fibers. In mice, we measured muscle strength by a grip strength test, muscle mass by bioimpedance and mass for specific muscles, and physical function by a treadmill test. We also detected the fiber's diameter and content of sarcomeric proteins. In C2C12 myotubes and/or isolated muscle fibers, we determined the diameter and troponin I level to validate the cellular effect. Moreover, to evaluate possible mechanisms, we detected puromycin incorporation, p70S6K, and 4EBP1 to evaluate protein synthesis and ULK1, LC3 I, and II protein levels to determine autophagic flux. The mitophagosome-like structures were detected by transmission electron microscopy. Results UDCA induced sarcopenia in healthy mice, evidenced by decreased strength, muscle mass, and physical function, with a decline in the fiber's diameter and the troponin I protein levels. In the C2C12 myotubes, we observed that UDCA caused a reduction in the diameter and content of MHC, troponin I, puromycin incorporation, and phosphorylated forms of p70S6K and 4EBP1. Further, we detected increased levels of phosphorylated ULK1, the LC3II/LC3I ratio, and the number of mitophagosome-like structures. These data suggest that UDCA induces a sarcopenic-like phenotype with decreased protein synthesis and autophagic flux. Conclusions Our results indicate that UDCA induces sarcopenia in mice and sarcopenic-like features in C2C12 myotubes and/or isolated muscle fibers concomitantly with decreased protein synthesis and alterations in autophagic flux.
Cholic and deoxycholic acids induce mitochondrial dysfunction, impaired biogenesis and autophagic flux in skeletal muscle cells
(BMC, 2023-06-08) Abrigo, Johanna; Olguín, Hugo; Tacchi, Franco; Orozco-Aguilar, Josué; Valero, Mayalen; Soto, Jorge; Castro-Sepulveda, Mauricio; Elorza, Alvaro A.; Simon, Felipe; Cabello-Verrugio, Claudio
Background Skeletal muscle is sensitive to bile acids (BA) because it expresses the TGR5 receptor for BA. Cholic (CA) and deoxycholic (DCA) acids induce a sarcopenia-like phenotype through TGR5-dependent mechanisms. Besides, a mouse model of cholestasis-induced sarcopenia was characterised by increased levels of serum BA and muscle weakness, alterations that are dependent on TGR5 expression. Mitochondrial alterations, such as decreased mitochondrial potential and oxygen consumption rate (OCR), increased mitochondrial reactive oxygen species (mtROS) and unbalanced biogenesis and mitophagy, have not been studied in BA-induced sarcopenia. Methods We evaluated the effects of DCA and CA on mitochondrial alterations in C2C12 myotubes and a mouse model of cholestasis-induced sarcopenia. We measured mitochondrial mass by TOM20 levels and mitochondrial DNA; ultrastructural alterations by transmission electronic microscopy; mitochondrial biogenesis by PGC-1α plasmid reporter activity and protein levels by western blot analysis; mitophagy by the co-localisation of the MitoTracker and LysoTracker fluorescent probes; mitochondrial potential by detecting the TMRE probe signal; protein levels of OXPHOS complexes and LC3B by western blot analysis; OCR by Seahorse measures; and mtROS by MitoSOX probe signals. Results DCA and CA caused a reduction in mitochondrial mass and decreased mitochondrial biogenesis. Interestingly, DCA and CA increased LC3II/LC3I ratio and decreased autophagic flux concordant with raised mitophagosome-like structures. In addition, DCA and CA decreased mitochondrial potential and reduced protein levels in OXPHOS complexes I and II. The results also demonstrated that DCA and CA decreased basal, ATP-linked, FCCP-induced maximal respiration and spare OCR. DCA and CA also reduced the number of cristae. In addition, DCA and CA increased the mtROS. In mice with cholestasis-induced sarcopenia, TOM20, OXPHOS complexes I, II and III, and OCR were diminished. Interestingly, the OCR and OXPHOS complexes were correlated with muscle strength and bile acid levels. Conclusion Our results showed that DCA and CA decreased mitochondrial mass, possibly by reducing mitochondrial biogenesis, which affects mitochondrial function, thereby altering potential OCR and mtROS generation. Some mitochondrial alterations were also observed in a mouse model of cholestasis-induced sarcopenia characterised by increased levels of BA, such as DCA and CA.
Targeting mitochondria for the prevention and treatment of nonalcoholic fatty liver disease: polyphenols as a non-pharmacological approach
(Bentham Science Publishers, 2022-11-08) Zapata, Jaime; Castro-Sepulveda, Mauricio; Soto-Alarcon, Sandra; Alvarez, Daniela; Bustamante, Andres; Villarroel, Guiselle; Gallardo, Arturo; Fernando García, Diego; Valenzuela, Rodrigo; Echeverria, Francisca
Scope: Nonalcoholic fatty liver disease (NAFLD) has a high and growing prevalence globally. Mitochondria are fundamental in regulating cell energy homeostasis. Nevertheless, mitochondria control mechanisms can be exceeded in this context of energy overload. Damaged mitochondria worsen NAFLD progression. Diet and lifestyle changes are the main recommendations for NAFLD prevention and treatment. Some polyphenols have improved mitochondrial function in different NAFLD and obesity models. Objective: The study aims to discuss the potential role of polyphenols as a nonpharmacological approach targeting mitochondria to prevent and treat NAFLD, analyzing the influence of polyphenols' chemical structure, limitations and clinical projections. Methods: In vivo and in vitro NAFLD models were considered. Study searches were performed using the following keywords: nonalcoholic fatty liver disease, liver steatosis, mitochondria, mitochondrial activity, mitochondrial dynamics, mitochondrial dysfunction, mitochondrial morphology, mitochondrial cristae, fusion, fission, polyphenols, flavonoids, anthocyanins, AND/OR bioactive compounds. Conclusion: Polyphenols are a group of diverse bioactive molecules whose bioactive effects are highly determined by their chemical structure. These bioactive compounds could offer an interesting non-pharmacological approach to preventing and treating NAFLD, regulating mitochondrial dynamics and function. Nevertheless, the mitochondria' role in subjects with NAFLD treatment is not fully elucidated. The dosage and bioavailability of these compounds should be addressed when studied.
Concurrent training and interindividual response in women with a high number of metabolic syndrome risk factors
(Frontiers Media S.A., 2022-09-22) Delgado-Floody, Pedro; Chirosa-Ríos, Luis; Caamaño-Navarrete, Felipe; Valdés-Badilla, Pablo; Herrera-Valenzuela, Tomás; Monsalves-Álvarez, Matías; Núñez-Espinosa, Cristian; Castro-Sepulveda, Mauricio; Guzmán-Muñoz, Eduardo; Andrade, David C.; Álvarez, Cristian
The non-responders (NRs) after exercise training have been poorly studied in populations with morbid obesity. The purpose of this study was to determine the NR prevalence after 20 weeks of concurrent training of morbidly obese women with a high or low number of metabolic syndrome (MetS) risk factors. Twenty-eight women with morbid obesity participated in an exercise training intervention and were allocated into two groups distributed based on a high (≥3, n = 11) or low number (<3, n = 17) of MetS risk factors. The main outcomes were waist circumference (WC), fasting plasma glucose (FPG), high-density lipids (HDL-c), triglycerides (Tg), and systolic (SBP) and diastolic (DBP) blood pressure, and secondary outcomes were body composition, anthropometric and physical fitness, determined before and after 20 weeks of concurrent training. NRs were defined as previously used technical error cut-off points for the MetS outcomes. Significantly different (all p < 0.05) prevalences of NRs between the H-MetS vs. L-MetS groups (respectively) in WC (NRs 18.2 % vs. 41.1 %, p < 0.0001), SBP (NRs 72.7 % vs. 47.0 %, p = 0.022), DBP (NRs 54.5 % vs. 76.4 %, p < 0.0001), FPG (NRs 100% vs. 64.8 %, p < 0.0001), and HDL-c (NRs 90.9 % vs. 64.7 %, p = 0.012) were observed. In addition, the H-MetS group evidenced significant changes on ΔSBP (−10.2 ± 11.4 mmHg), ΔFPG (−5.8 ± 8.2 mg/dl), ΔHDL-c (+4.0 ± 5.9 mg/dl), and ΔTg (−8.8 ± 33.8 mg/dl), all p < 0.05. The L-MetS group only showed significant changes in ΔWC (−3.8 ± 5.0 cm, p = 0.009). Comparing H-MetS vs. L-MetS groups, significant differences were observed in ∆FPG (−5.8 ± 8.2 vs. +0.3 ± 3.2 mg/dl, p = 0.027), but not in other MetS outcomes. In conclusion, 20 weeks of concurrent training promotes greater beneficial effects in morbidly obese patients with a high number of MetS risk factors. However, the NR prevalence for improving MetS outcomes was significantly superior in these more-diseased groups in SBP, FPG, and HDL-c, independent of their major training-induced effects.
Prescription of High-intensity aerobic interval training based on oxygen uptake kinetics
(Thieme, 2023) Festa, Raúl Ricardo; Monsalves-Álvarez, Matías; Cancino, Jorge; Jannas-Vela, Sebastián
Endurance training results in diverse adaptations that lead to increased performance and health benefits. A commonly measured training response is the analysis of oxygen uptake kinetics, representing the demand of a determined load (speed/work) on the cardiovascular, respiratory, and metabolic systems, providing useful information for the prescription of constant load or interval-type aerobic exercise. There is evidence that during high-intensity aerobic exercise some interventions prescribe brief interval times (<1-min), which may lead to a dissociation between the load prescribed and the oxygen uptake demanded, potentially affecting training outcomes. Therefore, this review explored the time to achieve a close association between the speed/work prescribed and the oxygen uptake demanded after the onset of high-intensity aerobic exercise. The evidence assessed revealed that at least 80% of the oxygen uptake amplitude is reached when phase II of oxygen uptake kinetics is completed (1 to 2 minutes after the onset of exercise, depending on the training status). We propose that the minimum work-time during high-intensity aerobic interval training sessions should be at least 1 minute for athletes and 2 minutes for non-athletes. This suggestion could be used by coaches, physical trainers, clinicians and sports or health scientists for the prescription of high-intensity aerobic interval training.
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.
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.
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.
The critical shoulder angle: a significant radiological measure in rotator cuff vs. glenohumeral osteoarthritis in chilean patients—a descriptive cross-sectional study
(MDPI, 2024-06-11) Rojas, Walter; Vargas, Pablo; Droppelmann, Guillermo; Jorquera, Carlos; Stöwhas Villarroel, Katherine; Godoy, Alejandro; García, Nicolás
Background: Shoulder pain is one of the most important musculoskeletal conditions affecting the upper extremities. Glenohumeral osteoarthritis (GHOA) and rotator cuff injuries (RCIs) are notable for their high prevalence. The critical shoulder angle (CSA) is a significant radiological measure for determining the diagnosis and progression of patients with these conditions. Although there are reports in the international literature about this measure, in our country, guideline values considering these two pathologies are unknown. Objective: Our objective was to assess patients diagnosed with GHOA and RCI using an AP X-ray view and the CSA. Methods: To conduct this, we identified differences between sexes and age categories. Fifty-nine adult patients with GHOA and RCI were included. CSA grades varied depending on the age category and type of injury evaluated. Results: Significant differences between the age ranges of 40 and 54 (p = 0.05), 55–69 (p = 0.001), and 70–84 (p = 0.017) were observed. Conclusions: Patients with RCI tended to be younger and have a higher CSA compared to those with GHOA. It is important to have more normative values and to continue monitoring the critical shoulder angle in these patients.

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