Browsing by Author "Fernandez-Verdejo, Rodrigo"
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- ItemDeciphering the constrained total energy expenditure model in humans by associating accelerometer-measured physical activity from wrist and hip(2021) Fernandez-Verdejo, Rodrigo; Alcantara, Juan M. A.; Galgani, Jose E.; Acosta, Francisco M.; Migueles, Jairo H.; Amaro-Gahete, Francisco J.; Labayen, Idoia; Ortega, Francisco B.; Ruiz, Jonatan R.The constrained total energy expenditure (TEE) model posits that progressive increases in physical activity (PA) lead to increases in TEE; but after certain PA threshold, TEE plateaus. Then, a compensatory reduction in the expenditure of non-essential activities constrains the TEE. We hypothesized that high PA levels as locomotion associate with a compensatory attenuation in arm movements. We included 209 adults (64% females, mean [SD] age 32.1 [15.0] years) and 105 children (40% females, age 10.0 [1.1] years). Subjects wore, simultaneously, one accelerometer in the non-dominant wrist and another in the hip for >= 4 days. We analyzed the association between wrist-measured (arm movements plus locomotion) and hip-measured PA (locomotion). We also analyzed how the capacity to dissociate arm movements from locomotion influences total PA. In adults, the association between wrist-measured and hip-measured PA was better described by a quadratic than a linear model (Quadratic-R-2=0.54 vs. Linear-R-2=0.52; P=0.003). Above the 80th percentile of hip-measured PA, wrist-measured PA plateaued. In children, there was no evidence that a quadratic model fitted the association between wrist-measured and hip-measured PA better than a linear model (R-2=0.58 in both models, P=0.25). In adults and children, those with the highest capacity to dissociate arm movements from locomotion-i.e. higher arm movements for a given locomotion-reached the highest total PA. We conclude that, in adults, elevated locomotion associates with a compensatory reduction in arm movements (probably non-essential fidgeting) that partially explains the constrained TEE model. Subjects with the lowest arm compensation reach the highest total PA.
- ItemEsteatohepatitis no-alcohólica: Desarrollo silencioso de una emergencia en salud pública(Soc. Chilena Nutrición, Bromatología & Toxicología, 2023) Pettinelli, Paulina; Fernandez-Verdejo, Rodrigo; Aguirre Polanco, Carolina
- ItemExploring the sequential accumulation of metabolic syndrome components in adults(2022) Fernandez-Verdejo, Rodrigo; Galgani, Jose E.The metabolic syndrome (MetS) is diagnosed upon the manifestation of & GE; 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 & GE; 18.5 kg/m(2), 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 (& GE; 91 cm for men, & GE; 83 cm for women), reduced high-density lipoprotein cholesterol (HDL-C; < 40 mg/dL for men, < 50 mg/dL for women), elevated triglycerides (& GE; 150 mg/dL), elevated blood pressure (& GE; 130 mmHg for systolic, or & GE; 85 mmHg for diastolic), and elevated glycemia (& GE; 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.
- ItemLow 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(2021) Castro-Sepulveda, Mauricio; Fernandez-Verdejo, Rodrigo; Tunon-Suarez, Mauro; Morales-Zuniga, Jorge; Troncoso, Mayarling; Jannas-Vela, Sebastian; Zbinden-Foncea, HermannThe 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.
- ItemPathophysiological role of metabolic flexibility on metabolic health(2020) Galgani Fuentes, José; Fernandez-Verdejo, RodrigoGlucose, fatty acids, and amino acids among others are oxidized to generate adenosine triphosphate (ATP). These fuels are supplied from the environment (through food intake) and internal depots (through lipolysis, glycogenolysis, and proteolysis) at different rates throughout the day. Complex adaptive systems permit to accommodate fuel oxidation according to fuel availability. This capacity of a cell, tissue, or organism to adapt fuel oxidation to fuel availability is defined as metabolic flexibility (MetF). There are conditions, such as insulin resistance, diabetes, and obesity, in which MetF seems to be impaired. The observation that those conditions are accompanied by mitochondrial dysfunction has set the basis to propose a link between mitochondrial dysfunction, metabolic inflexibility, and metabolic health. We here highlight the evidence about the notion that MetF influences metabolic health.
- ItemPredicting academic success in undergraduate students from the Nutrition and Dietetics degree program from the Pontificia Universidad Católica de Chile(2024) Pettinelli, Paulina; Fernandez-Verdejo, Rodrigo; Fredes, Carolina; Parada, Alejandra; Aguirre, CarolinaIntroduction: Identifying the factors that determine academic success can help design strategies focused on increasing academic success. We aimed to identify predictors associated with academic success in undergraduate students of the Nutrition and Dietetics Program of the Pontificia Universidad Cat & oacute;lica de Chile (PUC). Methods: Retrospective study using the institutional database. Academic success was the main outcome, including two indexes: i) final grade point average (GPA-f) and; ii) timely graduation, defined as graduating in <= 10 semesters. Candidate predictors were: age, sex, region of origin, school attended, score at the university selection test (PSU-score), admission route, and preference for the program. Stepwise linear regression was used to identify predictors of GPA-f. Binary logistic regression was used to identify variables associated with timely graduation. Results: PSU-score was the only predictor of GPA, explaining 24% of its variance. The odds (OR [95%CI]) for a timely graduation were influenced by PSU-score (1.017 [1.003- 1.031]) and admission route (PSU 1.00 [Reference], Inclusive 0.30 [0.10- 0.96], Special 0.46 [0.13- 1.57]). Conclusions and implications: PSU-score partially predicts the academic success of Nutrition and Dietetics students. In addition, students who accessed the program by the equity admission had lower odds of a timely graduation. As educational inequalities may affect academic success, the teaching and learning process needs to be addressed with specific strategies for these students to ensure academic success.
- ItemPrevalence 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(2023) Pettinelli Rocha, Paulina Pilar; Fernández Mincone, Tiziana; Aguirre Polanco, Carolina; Barrera Martínez, Francisco José; Riquelme Pérez, Arnoldo; Fernandez-Verdejo, Rodrigo© The Authors 2023.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.
- ItemTime reallocation of physical behaviours induced by endurance exercise in physically active individuals(2023) Hayes-Ortiz, Thomas; Suarez-Reyes, Monica; Galgani Fuentes, José Eduardo; Zbinden-Foncea, Hermann; Fernandez-Verdejo, RodrigoIncreasing moderate-vigorous physical activity (MVPA) through exercise requires reallocating time from other physical behaviour(s). We aimed to determine the reallocations induced by endurance exercise in physically active individuals. We also searched for behavioural compensatory responses, and explored the effect of exercise on daily energy expenditure. Fourteen participants (8 women; median age 37.8 [IQR 29.9-48.5] yr) exercised on Monday, Wednesday, and Friday mornings (cycling MVPA, 65 min/session; "exercise days"), and avoided exercising on Tuesday and Thursday ("rest days"). Time spent on sleep, sedentary behaviour, light-intensity physical activity, and MVPA was determined each day by accelerometers and logs. An energy expenditure index was computed considering minutes spent on each behaviour and fixed metabolic equivalents. We found that all participants had lower sleep and higher total (including exercise) MVPA on exercise days compared to rest days. Thus, on exercise vs. rest days, sleep was lower (490 [453-553] vs. 553 [497-599] min/day, respectively, P < 0.001), and total MVPA was higher (86 [80-101] vs. 23 [15-45] min/day, respectively; P < 0.001). No differences in other physical behaviours were detected. Notably, exercise not only induced reallocations (i.e. less time in other behaviours) but also behavioural compensatory responses in some participants (e.g. increased sedentary behaviour). This rearrangement of physical behaviours manifested in exercise-induced increases in energy expenditure from 96 to 232 MET x min/day. In conclusion, active individuals reallocated time from sleep to accommodate morning exercise. Yet exercise induced variable rearrangements of behaviours, with some individuals manifesting compensatory responses. Understanding individual rearrangements may help improve exercise interventions.
- ItemValidity of predictive equations for resting metabolic rate in healthy humans(2018) Galgani Fuentes, José; Castro Sepúlveda, Mauricio; Perez-Luco, Cristian; Fernandez-Verdejo, Rodrigo