The use of oxygen as a possible screening biomarker for the diagnosis of chronic fatigue

Background: The aim of this study was to verify whether the mean percentage of oxygen use in the aerobic-anaerobic transition phase or isocapnic buffering (IB) was lower in women with chronic fatigue syndrome (CFS) compared to healthy women, and if this variable could be used as a screening biomarker for the diagnosis of CFSMethodsA cross-sectional study was conducted. Forty-four adult women (22 with CFS and 22 healthy) performed a cycle ergometer stress test with gas analyser (CPET). Maximum oxygen consumption (V˙O2 max), oxygen consumption at the anaerobic threshold (V˙O2 at Vt2), maximum ventilatory volume (V˙E max), time of maintenance of the isocapnic buffering phase (IB duration), and mean percentage of oxygen use in isocapnic buffering phase (% O2 use in IB) were analyzed. Data were explored from a principal component analysis. Groups were matched by propensity score to be mismatched in BMI and a comparison of means and medians was performed. A logistic regression model was built to predict the probability of CFS.ResultsThe mean and median values of the variables obtained in the CPET was significantly higher in the healthy group compared to the CFS. In the logistic regression model, VO2 max, IB duration, and mean % of O2 use in IB were selected as predictors. The sensitivity and specificity were greater than 90%.ConclusionThe combination of the factors V˙O2 max, IB duration, and mean % of O2 use in IB can be used as a screening biomarker for the diagnosis of CFS. (AU)

Motivaciones, barreras y condición física en adolescentes según el estadio de cambio en ejercicio físico / Motivations, barriers and physical condition in adolescents, according to the stage of change in physical exercise / Motivações, barreiras e condição física em adolescentes, de acordo com o estágio de mudança no exercício físico

Mediante un estudio descriptivo y transversal se realiza una clasificación sobre el momento de cambio en ejercicio físico en adolescentes y se analiza la relación con las motivaciones, barreras y condición física en una muestra de 379 jóvenes españoles de 12 a 16 años. Estas valoraciones permiten fundamentar y elaborar propuestas de actuación para mejorar el proceso de cambio de hábito hacia el ejercicio físico. Los resultados muestran que la mayoría de la población estudiada (52.2%) se halla en la etapa de Mantenimiento observando una diferencia en las mujeres (38.3%), y una alarmante disminución de actividad física según aumenta la edad. Las motivaciones más destacadas son la de prevención y salud, seguida por la búsqueda de diversión y bienestar; las barreras más manifiestas son las obligaciones y falta de tiempo. Por ello los programas de intervención deberían tener muy en cuenta dichos aspectos, ofrecer actividades compatibles con los horarios escolares, generando contextos motivantes y adaptadas al estadio en el que se encuentra el sujeto

Through a descriptive and cross-sectional study, a classification is made on the moment of change in physical exercise in adolescents and the relationship with motivations, barriers and physical condition is analyzed in a sample of 379 Spanish young people between 12 and 16 years of age. These evaluations make possible to prepare a basis for an action's proposal to improve the process of changing habits towards physical exercise. The results show that the majority of the study popu-lation (52.2%) is in the Maintenance stage, observing a difference in women (38.3%), and an alarming decrease in physical activity as age increases. The most outstanding motivations are prevention and health, followed by the search for fun and well-being; The most obvious barriers are obligations and lack of time. For this reason, intervention programs should consider these aspects, offering activities compatible with school hours, generating motivational contexts and adapted to the stage in which the subject is

Por meio de um estudo descritivo e transversal, é feita uma classificação sobre o momento de mudança no exercício físico em adolescentes e a relação com motivações, barreiras e condição física é analisada em uma amostra de 379 jovens espa¬nhóis de 12 a 16 anos. Essas avaliações possibilitam basear e preparar propostas de ação para melhorar o processo de mudança de hábitos em relação ao exercício físico. Os resultados mostram que a maioria da população estudada (52,2%) está na fase de manutenção, observando uma diferença entre as mulheres (38,3%) e uma diminuição alarmante da atividade física com o aumento da idade. As motivações mais destacadas são a prevenção e a saúde, seguidas pela busca de diversão e bem-estar; As barreiras mais óbvias são obrigações e falta de tempo. Por esse motivo, os programas de intervenção devem levar em consideração esses aspectos, oferecendo atividades compatíveis com o horário escolar, gerando contextos motivadores e adaptados ao estágio em que o sujeito se encontra