Daniel Brotons

Inter-individual variability in right ventricle adaptation after an endurance race.

Background Right ventricle (RV) dysfunction has been described in athletes after endurance races. We aimed to understand and characterize the RV response to endurance exercise, the impact of individual variability and the effects of the amount of exercise. Methods and results Echocardiography was performed in 55 healthy adults at baseline and after a three-stage trail race: short (14 km; n = 17); medium (35 km; n = 21); and long (56 km; n = 17). Standard and speckle tracking echocardiographic assessment of the RV was performed with global and separate analysis of the RV basal (inflow) and apical regions. Although no change was observed in the short distance runners, the RV systolic deformation decreased significantly (p < 0.05) after both the medium length and long races (Δ% RV global strain −7.6 ± 20.1 and −8.7 ± 21.8, respectively) with significant RV dilatation (Δ% RV volume +10.6 ± 9.9 and +15.3 ± 12.8, respectively). The RV basal segment made a major contribution to stroke volume during exercise, showing larger increases in size and strain compared with the apex. Various patterns of RV adaptation to exercise, ranging from increases in both RV segmental strains and sizes to an insufficient increase in size and a decrease in strain, were identified; this individual variability was not correlated with prior training. Conclusion An acute RV impairment was demonstrated after a trail-running race and was related to the amount of exercise. A high inter-individual variability was observed. Differences in RV adaptation patterns were independent of prior training, suggesting the influence was due to other individual factors.

Sarcomere Disruptions of Slow Fiber Resulting From Mountain Ultramarathon

OBJECTIVE To investigate changes after a mountain ultramarathon (MUM) in the serum concentration of fast (FM) and slow (SM) myosin isoforms, which are fiber-type-specific sarcomere proteins. The changes were compared against creatine kinase (CK), a widely used fiber-sarcolemma-damage biomarker, and cardiac troponin I (cTnI), a widely used cardiac biomarker. METHODS Observational comparison of response in a single group of 8 endurance-trained amateur athletes. Time-related changes in serum levels of CK, cTnI, SM, and FM from competitors were analyzed before, 1 h after the MUM, and 24 and 48 h after the start of the MUM by 1-way ANOVA for repeated measures or Friedman and Wilcoxon tests. Pearson correlation coefficient was employed to examine associations between variables. RESULTS While SM was significantly (P = .009) increased in serum 24 h after the beginning of the MUM, FM and cTnI did not change significantly. Serum CK activity peak was observed 1 h after the MUM (P = .002). Moreover, serum peaks of CK and SM were highly correlated (r = .884, P = .004). CONCLUSIONS Since there is evidence of muscle damage after prolonged mountain running, the increase in SM serum concentration after a MUM could be indirect evidence of slow- (type I) fiber-specific sarcomere disruptions.

Affected pathways and transcriptional regulators in gene expression response to an ultra-marathon trail: Global and independent activity approaches

Gene expression (GE) analyses on blood samples from marathon and half-marathon runners have reported significant impacts on the immune and inflammatory systems. An ultra-marathon trail (UMT) represents a greater effort due to its more testing conditions. For the first time, we report the genome-wide GE profiling in a group of 16 runners participating in an 82 km UMT competition. We quantified their differential GE profile before and after the race using HuGene2.0st microarrays (Affymetrix Inc., California, US). The results obtained were decomposed by means of an independent component analysis (ICA) targeting independent expression modes. We observed significant differences in the expression levels of 5,084 protein coding genes resulting in an overrepresentation of 14% of the human biological pathways from the Kyoto Encyclopedia of Genes and Genomes database. These were mainly clustered on terms related with protein synthesis repression, altered immune system and infectious diseases related mechanisms. In a second analysis, 27 out of the 196 transcriptional regulators (TRs) included in the Open Regulatory Annotation database were overrepresented. Among these TRs, we identified transcription factors from the hypoxia-inducible factors (HIF) family EPAS1 (p< 0.01) and HIF1A (p<0.001), and others jointly described in the gluconeogenesis program such as HNF4 (p< 0.001), EGR1 (p<0.001), CEBPA (p< 0.001) and a highly specific TR, YY1 (p<0.01). The five independent components, obtained from ICA, further revealed a down-regulation of 10 genes distributed in the complex I, III and V from the electron transport chain. This mitochondrial activity reduction is compatible with HIF-1 system activation. The vascular endothelial growth factor (VEGF) pathway, known to be regulated by HIF, also emerged (p<0.05). Additionally, and related to the brain rewarding circuit, the endocannabinoid signalling pathway was overrepresented (p<0.05).

Bioelectrical impedance vector analysis (BIVA) for measuring the hydration status in young elite synchronized swimmers

Purpose The assessment of body hydration is a complex process, and no measurement is valid for all situations. Bioelectrical impedance vector analysis (BIVA) has emerged as a relatively novel technique for assessing hydration status in sports. We applied BIVA a) to determine hydration changes evoked by an intense synchronized swimming (SS) training session; b) to characterize the sample of young elite swimmers in relation with a nonathletic reference population; and c) to generate its 50%, 75% and 95% percentiles of the bioelectrical variables. Methods Forty-nine elite SS female swimmers of two age categories, comen (Co: 13.9 ± 0.9 years, n = 34) and junior (Jr: 16.3 ± 0.6 years, n = 15), performed a long, high intensity training session. Body mass (BM) and bioelectrical variables (R, resistance; Xc, reactance; PA, phase angle; and Z, impedance module) were assessed pre- and post-training. BIVA was used to characterize 1) the distribution pattern of the bioelectrical vector (BIA vector) for both age groups, and 2) pre- to post-training BIA vector migration. Bioelectrical variables were also correlated with BM change values. Results Most swimmers were mostly located outside the 75% and some beyond the 95% percentile of the bioelectrical tolerance ellipses of the general population. The BIA vector showed statistically significant differences in both Co (T2 = 134.7, p = 0.0001) and Jr (T2 = 126.2, p < 0.001). Both groups were also bioelectrically different (T2 = 17.6, p < 0.001). After the training session, a decrease in BM (p = 0.0001) and an increase in BIA variables (p = 0.01) was observed. BIVA also showed a significant pre-post vector migration both in Co (T2 = 82.1; p < 0.001) and Jr (T2 = 41.8; p < 0.001). No correlations were observed between BM changes and bioelectrical variables. Conclusions BIVA showed specific bioelectrical characteristics in young elite SS athletes. Considering the decrease in BM and the migration of the BIA vector, we conclude that the homeostatic hydration status of these young elite female swimmers was affected by the execution of intense training sessions. From a methodological perspective, BIVA appears to be sensitive enough to detect subtle hydration changes, but further research is needed to ensure its validity and reliability. Moreover, these findings highlight the importance of ensuring adequate fluid intake during training in young SS athletes.

Training-induced gene expression plasticity in cardiac function and neural regulation for ultra-trail runners

This study aims to assess the gene regulatory response from a group of 16 athletes and to observe the plasticity induced by their training regime on the gene expression response after their participation in an 82km race. Blood samples for differential gene expression (DGE) were collected before and after this effort from two groups of runners with different training regimes: elite and active. Analyses only focused on genes annotated as related to cardiac function (CF) and neural regulation (NR) from the KEGG PATHWAY Database. Thus, 13 pathways were considered accounting for a total of 629 genes. Training regime modulated the response to exercise based on a list of 18 ranked genes with significant DGE for elite runners while remained statistically insignificant for active athletes. UQCR11, COX7C and COX4I1 genes, related to mitochondrial respiratory chain, were down-regulated which may indicate mitochondrial function impairment in cardiac muscle. Increased expression levels were obtained for PIK3R2, PLCG2, IRAK3 genes from the positive signaling cascades of neurotrophins pathway, which may reveal an improved heart rate control thanks to a better cardiac sympathetic innervation.

Agentes infecciosos en la génesis de la hipertrofia cardíaca del deportista.

Objetivo Evaluar la prevalencia de infeccion e inflamacion en deportistas de alto volumen de entrenamiento que reunen criterios de corazon de atleta. Metodo Hemos estudiado 13 deportistas de alto nivel, practicantes de diversos deportes (acuaticos, colectivos e individuales), con edades entre 19 y 29 anos y con criterios de masa ventricular izquierda aumentada (>230 g). demostrada por Eco-cardiografia Doppler-color sin sintomatologia clinica previa. Todos ellos superaron una bateria de pruebas estandar (estudio clinico, ergometria y ecocardiografia doppler) y una analitica donde se valoro la serologia que demostrara un contacto con Chlamydia pneumoniae (Chp), Micoplasma (Mp), virus Coxackie A y B (CxA y CxB), Echo virus (Ev) y Adenovirus (Av), junto a marcadores inflamatorios, principalmente la Proteina C Reactiva (marcador reactante de la fase aguda). Resultados En nuestra serie, un 62% de los atletas estudiados tuvieron contactos previos con Mp, un 54% con Chp, y superior al 90% en el resto de los germenes (CxA y CxB, Ev yAv). Un estudio Ac-IgG en atletas demostro un contagio para las Chp del 46% y para el Mp del 36%. La Proteina C Reactiva (PCR) fue superior a 2 mg en el atleta con titulo de Ac mas elevado, y poseedor de la mayor dilatacion ventricular izda. (DTd de 61 mm). La infeccion previa por Chp ofrece una cierta correlacion (r 0.74) con los niveles de PCR, siendo la correlacion maxima en deportes acuaticos y menor en el resto de deportes estudiados (colectivos e individuales). Conclusion Existe una prevalencia elevada de infeccion por microorganismos miotroficos en esta serie de deportistas. Recomendamos, en el futuro, estudiar series mas amplias al objeto de acotar las variables que inciden en la patogenesis de la hipertrofia y/o dilatacion cardiaca del deportista.