Swimming training repercussion on metabolic and structural bone development: benefits of the incorporation of whole body vibration or pilometric training; the RENACIMIENTO project

Introduction: Enviromental factors such as exercise participation and nutrition have often been linked to bone improvements. However, not all sports have the same effects, being non-osteogenic sports such as swimming defined as negative or neutral sports to practice regarding bone mass by some authors, similarly exercise-diet interaction in especific groups is still not clear. Objective: To present the methodology of the RENACIMENTO project that aims to evaluate body composition and more specifically bone mass by several techniques in adolescent swimmers and to observe the effects and perdurability of whole body vibration (WBV) and jumping intervention (JIN) on body composition and fitness on this population and explore posible diet interactions. Design: Randomized controlled trial. Methods: 78 swimmers (12-17 y) and 26 sex- and age-matched controls will participate in this study. Dual energy X-ray, peripheral Quantitative Computed Tomography, Quantitative Ultrasound, Bioelectrical Impedance Analysis, and anthropometry measurements will be performed in order to evaluate body composition. Physical activity, nutrition, pubertal development and socio-economical status may act as confounders of body composition and therefore will also be registered. Several fitness factors regarding strength, endurance, performance and others will also be registered to evaluate differences with controls and act as confounders. A 7-month WBV therapy will be performed by 26 swimmers consisting of a training of 15 minutes 3 times per week. An 8 month JIM will also be performed by 26 swimmers 3 times per week. The remaining 26 swimmers will continue their normal swimming training. Four evaluations will be performed, the first one in order to describe differences between swimmers and controls. The second one to describe the effects of the interventions and the third and fourth evaluations to describe the perdurability of the effects of the WBV and JIN. Conclusion: The RENACIMIENTO project will allow to answer several questions regarding body composition, fitness, bone mass and interaction with diet of adolescent swimmers, describe swimming as a positive, negative or neutral sport to practice regarding these parameters and elucidate the effects and perdurability of WBV and JIM on body composition.

Characteristics of Clostridium difficile infection in patients with discordant diagnostic test results

Background: Clinical features of Clostridium difficile infection (CDI) cases diagnosed by detection of polymerase chain reaction (PCR), with negative toxin enzyme immunoassay results (EIA) have not been fully elucidated. The purpose of this study was to determine the magnitude of CDI patients who had negative EIA toxin determinations but positive PCR tests, and their differences in clinical presentation. Methods: We performed a retrospective study comparing the clinical features of CDI cases detected by EIA (toxins A + B) with cases detected by PCR (toxin negative, PCR positive) over a 16-month period. Only patients with an initial Clostridium difficile infection episode that fulfilled a standardized definition were included. Results: During the study period, 107 episodes of CDI were detected. Seventy-four patients (69%) had positive glutamate dehydrogenase (GDH) antigen and EIA determinations (EIA positive patients). Thirty-three patients (31%) had GDH positive, negative toxin EIA and positive PCR determination (PCR positive patients). PCR positive patients were younger, 57 (27) years (mean [SD]), than EIA positive patients, 71 (16) years, (p < 0.001). Fewer PCR positive patients were receiving proton pump inhibitors (21 patients, 64%) than EIA positive patients (61 patients, 82%, p = 0.034). The clinical presentation was similar in both groups. In the multivariate analysis, lower age was identified as the only independent variable associated with PCR positive patients. Conclusions: One third of Clostridium difficile infection patients present negative toxin EIA and PCR positive tests. Performing PCR determination after the negative EIA test is more relevant in younger patients.