Association Between Total Genotype Score and Muscle Injuries in Top-Level Football Players: a Pilot Study.

BACKGROUND: Recently, genetic predisposition to injury has become a popular area of research and the association between a few single nucleotide polymorphisms (SNPs) and the susceptibility to develop musculoskeletal injuries has been shown. This pilot study aimed to investigate the combined effect of common gene polymorphisms previously associated with muscle injuries in Italian soccer players. RESULTS: A total of 64 Italian male top football players (age 23.1 ± 5.5 years; stature 180.2 ± 7.4 cm; weight 73.0 ± 7.9 kg) were genotyped for four gene polymorphisms [ACE I/D (rs4341), ACTN3 c.1729C > T (rs1815739), COL5A1 C > T (rs2722) and MCT1 c.1470A > T (rs1049434)]. Muscle injuries were gathered for 10 years (2009-2019). Buccal swabs were used to obtain genomic DNA, and the PCR method was used to genotype the samples. The combined influence of the four polymorphisms studied was calculated using a total genotype score (TGS: from 0 to 100 arbitrary units; a.u.). A genotype score (GS) of 2 was assigned to the "protective" genotype for injuries, a GS of 1 was assigned to the heterozygous genotype while a GS of 0 was assigned to the "worst" genotype. The distribution of genotype frequencies in the ACE I/D (rs4341), ACTN3 c.1729C > T (rs1815739) and MCT1 c.1470A > T (rs1049434) polymorphisms was different between non-injured and injured football players (p = 0.001; p = 0.016 and p = 0.005, respectively). The incidence of muscle injuries was significantly different among the ACE I/D (rs4341), ACTN3 c.1729C > T (rs1815739) and COL5A1 C > T (rs2722) genotype groups, showing a lower incidence of injuries in the "protective" genotype than "worse" genotype (ACE, p < 0.001; ACTN3, p = 0.005) or intermediate genotype (COL5A1, p = 0.029). The mean TGS in non-injured football players (63.7 ± 13.0 a.u.) was different from that of injured football players (42.5 ± 12.5 a.u., p < 0.001). There was a TGS cut-off point (56.2 a.u.) to discriminate non-injured from injured football players. Players with a TGS beyond this cut-off had an odds ratio of 3.5 (95%CI 1.8-6.8; p < 0.001) to suffer an injury when compared with players with lower TGS. CONCLUSIONS: These preliminary data suggest that carrying a high number of "protective" gene variants could influence an individual's susceptibility to developing muscle injuries in football. Adapting the training load parameters to the athletes' genetic profile represents today the new frontier of the methodology of training.

Collagen Gene Variants and Anterior Cruciate Ligament Rupture in Italian Athletes: A Preliminary Report.

Several studies have investigated the role of genetics in anterior cruciate ligament (ACL) rupture, often returning conflicting results. The present pilot study aimed to analyze the association between six Single Nucleotide Polymorphisms (SNPs) (rs1800012; rs12722; rs13946; rs240736; rs970547; and rs4870723, located on the COL1A1, COL5A1, COL12A1, and COL14A1 genes), and ACL rupture, among Italian athletes. A hypothesis-driven association study was conducted. In total, 181 male and female athletes (n = 86 injured; n = 96 non-injured) were genotyped for the prioritized variants. All polymorphisms were genotyped using PCR RFLP, with the only exception being the rs1800012 on the COL1A1 gene, which was detected using MTPA PCR. The allele frequency distribution fell within the worldwide range. Despite the evident population variability, no selective pressure signals were recorded using PBS analysis. No significant difference was detected between the cases and controls for any of the SNPs (rs1800012; rs13946; rs240736; rs970547, and rs4870723) included in the analyses (p > 0.008, Bonferroni-adjusted for multiple comparisons). Moreover, no significant differences were found when males and females were assessed separately. Further investigations based on a larger sample size are needed, in order to draw solid conclusions for the influence between collagen genes and ACL rupture.

Are Football Players More Prone to Muscle Injury after COVID-19 Infection? The "Italian Injury Study" during the Serie a Championship.

INTRODUCTION: Football was the first sport to resume competitions after the coronavirus disease 2019 (COVID-19) lockdown and promptly the hypothesis was raised of a potential relationship between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and musculoskeletal injuries in athletes. This study aimed to confirm the association between SARS-CoV-2 infection and muscle strain injury in a large population of elite football players and to investigate if the COVID-19 severity level could affect the risk of injury. METHODS: A retrospective cohort study involving 15 Italian professional male football teams was performed during the Italian Serie A 2020-2021 season. Injuries and SARS-CoV-2 positivity data were collected by team doctors through an online database. RESULTS: Of the 433 included players, we observed 173 SARS-CoV-2 infections and 332 indirect muscle strains. COVID-19 episodes mostly belonged to severity level I and II. The injury risk significantly increased after a COVID-19 event, by 36% (HR = 1.36, CI95% 1.05; 1.77, p-value = 0.02). The injury burden demonstrated an 86% increase (ratio = 1.86, CI95% 1.21; 2.86, p-value = 0.005) in the COVID-19 severity level II/III versus players without a previous SARS-CoV-2 infection, while level I (asymptomatic) patients showed a similar average burden (ratio = 0.92, CI95% 0.54; 1.58, p-value = 0.77). A significantly higher proportion of muscle-tendon junction injuries (40.6% vs. 27.1%, difference = 13.5%, CI95% 0.002%; 26.9%, p-value = 0.047) was found when comparing level II/III versus Non-COVID-19. CONCLUSIONS: This study confirms the correlation between SARS-CoV-2 infection and indirect muscle injuries and highlights how the severity of the infection would represent an additional risk factor.

The Athlete after COVID-19 infection: what the scientific evidence? What to do?

The coronavirus-19 disease (COVID-19) related pandemic have deeply impacted human health, economy, psychology and sociality. Possible serious cardiac involvement in the infection has been described, raising doubts about complete healing after the disease in many clinical settings. Moreover, there is the suspicion that the vaccines, especially those based on mRNA technology, can induce myopericarditis. Myocarditis or pericarditis related scars can represent the substrate for lifethreatening arrhythmias, triggered by physical activity. A crucial point is how to evaluate an athlete after a Covid-19 infection ensuring a safe return to play without increasing the number of unnecessary disqualifications from sports competitions. The lack of conclusive scientific data significantly increases the difficulty to propose recommendations and guidelines on this topic. At the same time, the psychological and physical negative consequences of unnecessary sports restriction must be taken into account. The present document aims to provide an updated brief review of the current knowledge about the COVID-19 cardiac involvement and how to recognize it and to offer a roadmap for the management of the athletes after a Covid-19 infections, including subsequent impact on exercise recommendations. Our document exclusively refers to cardiovascular implications of the disease, but pulmonary consequences are also considered.

Return to Play after SARS-CoV-2 Infection in Competitive Athletes of Distinct Sport Disciplines in Italy: A FMSI (Italian Federation of Sports Medicine) Study.

BACKGROUND: SARS-CoV-2 can lead to several systemic complications, including myocardial injuries; these might be worsened by heavy physical activity. The optimal approach to cardiac risk stratification following SARS-CoV-2 infection in athletes for a safe return to play (RTP) still needs defining. The aim of this study was to assess the prevalence of abnormal RTP test results, according to the protocol of Italian Federation of Sport Medicine (FMSI), which was endorsed by the Italian Ministry of Health, potentially representing COVID-19-associated cardiac injuries. METHODS: This was a prospective, multicenter, observational study. All consecutive competitive athletes who underwent COVID-19 RTP testing protocol from 1 May to 31 July 2021, across 60 Italian Centers of Sports Medicine, were enrolled in the study. Athletes were tested at least 30 days after negativization of the nasopharyngeal swab (or immediately after negativization in professional athletes or Probable Olympians). A 12-lead electrocardiography at rest and during maximal incremental exercise test with continuous O2 saturation monitoring and an echocardiographic examination were part of the protocol. In athletes with "moderate" disease (NHI classification), 24 h ECG monitoring (to be performed on a training day) and Magnetic Resonance Imaging (MRI) were also performed. RESULTS: A total of 4143 athletes (67.8% males and 32.2% females) (53% > 18 years, 20% 18-35 years and 16% > 35 years), from more than 40 different sport disciplines, were included in the study. The mean age was 22.5 ± 13.3 years, with ages ranging from 8 to 80 years. Of these athletes, 52.3% were asymptomatic, 46.4% manifested mild symptoms, 1.1% and 0.14% had moderate or severe symptoms, respectively, while critical illness was evident in one athlete. Abnormal echocardiographic findings were detected in 80 cases (1.9%), and pericarditis in 7 cases (0.2%); all were from mildly symptomatic athletes. Arrhythmic events were recorded in 239 athletes, with 224 (5.4%) in the exercise test and 15 (0.4%) during 24 h ECG monitoring. Ventricular arrhythmias were observed in 101 (2.4%) athletes from the total population (mostly isolated or couples of premature ventricular beats): 91 in the exercise test and 10 during 24 h ECG monitoring. Cardiac magnetic resonance was performed in 34 athletes; the presence of myocarditis was confirmed in 5 athletes (0.12% of the total population, 14.7% of athletes in which MRI was performed). CONCLUSIONS: According to our results, cardiac complications from SARS-CoV-2 in asymptomatic or mildly symptomatic competitive athletes are rare, and an RTP assessment based on symptoms and ECG-monitored exercise test would ensure a safe RTP in these athletes.

Body composition changes during the lockdown-restart transition due to the SARS-CoV-2 pandemic in a group of professional football players.

BACKGROUND: At the beginning of March 2020, because of the ongoing pandemic, all sport events were suspended in Italy. The Italian Serie A league abruptly interrupted all competitions and teams could not train in a group anymore. These containment measures were gradually eased in May. The aim of this study was to ascertain the impact of the lockdown-restart transition on the body composition of a group of Italian footballers of a Serie A team during the pandemic. METHODS: The body composition of 18 male football players (age 27.6±4.5 years) from an Italian Serie A team was studied by bioelectrical impedance (BIA). Measures were conducted after lockdown, when they restarted to train in group with the ball (T0), and after the first regular match (T1). RESULTS: Results show that there were no changes in body mass, body mass index, fat mass, fat-free mass, and total body water between T0 and T1. Differently, intracellular water, extracellular water, and phase angle were changed. CONCLUSIONS: We concluded that the lockdown did not have any impact in athletes' body composition as they kept training at home. Moreover, the BIA method was able to detect subtle signals of shift in body water compartments (intra cellular and extra cellular water) likely due to the different kind of training conducted during and after the lockdown.

Association between the ACE I/D polymorphism and muscle injuries in Italian and Japanese elite football players.

ACE I/D polymorphism has been recently associated with the susceptibility to inflammation and muscle damage after exercise. The aim of this study was to understand the association between the ACE I/D polymorphism and muscle injuries in a large cohort of elite football players from two different countries. Seven hundred and ten male elite football players from Italy (n = 341) and Japan (n = 369) were recruited for the study. Genomic DNA was extracted from either the buccal epithelium or saliva using a standard protocol. Structural-mechanical injuries and functional muscle disorders were recorded from 2009 to 2018. A meta-analysis was performed using Review Manager 5.3.5. In the Japanese cohort, the ACE I/D polymorphism was significantly associated with muscle injury using the D-dominant model (OR: 0.48, 95% CI: 0.24-0.97, P = 0.040). The meta-analysis showed that in the pooled model (Italian and Japanese populations), the frequencies of the DD+ID genotypes were significantly lower in the injured groups than in non-injured groups (OR: 0.61, 95% CI: 0.38-0.98, P = 0.04) with a low degree of heterogeneity (I2  = 0%). Our findings suggest that the ACE I/D polymorphism could influence the susceptibility to developing muscle injuries among football players.

Association of Monocarboxylate Transporter-1 (MCT1) A1470T Polymorphism (rs1049434) with Forward Football Player Status.

The aim of this study was to investigate the association between the MCT1 (monocarboxylate transporter 1) A1470T polymorphism and positional roles in a large cohort of professional football players from five different countries. We compared genotype distributions of the MCT1 A1470T polymorphism between football players (n=694) and non-athlete controls (n=781) from Italy, Poland, Lithuania, Ukraine and Malta, and we analyzed the MCT1 genotype distributions with respect to the players' positions in the field (e. g. forwards, midfielders, defenders and goalkeepers). Genomic DNA was extracted from either buccal epithelium or peripheral blood using a standard protocol. In the pooled cohort of Italian, Polish, Lithuanian and Ukrainian football players, forwards (n=148) were more likely than controls (n=781) to possess the A allele (χ2=7.067, p=0.029, FDR q value 0.116), with a greater likelihood of having the AA genotype compared with the TT genotype (OR=1.97; C.I.=1.07-3.64; p=0.021, FDR q value 0.086). The MCT1 AA genotype was significantly more frequent in forwards then in controls. Further studies are needed to confirm these findings in other professional football player cohorts.

Association Between MCT1 A1470T Polymorphism and Fat-Free Mass in Well-Trained Young Soccer Players.

The aim of this study was to investigate the association between the MCT1 A1470T polymorphism and fat-free mass in young Italian elite soccer players. Participants were 128 Italian male soccer players. Fat-free mass was estimated for each of the soccer player using age- and gender-specific formulas with plicometry. Genotyping for the MCT1 A1470T polymorphism was performed using polymerase chain reaction. The MCT1 A1470T genotypes were in agreement with the Hardy-Weinberg equilibrium distribution. The percentage of fat-free mass was significantly higher in soccer players with the TT genotype and in the T-allele-dominant model group (TT + AT) compared with the soccer players with the AA genotype. The MCT1 T allele is associated with the percentage of fat-free mass in young elite male soccer players. Elucidating the genetic basis of body composition in athletes could potentially be used as an additional tool for strength and conditioning professionals in planning and adjusting training. However, these results are preliminary and need to be replicated in more cohorts.

Influence of the MCT1 rs1049434 on Indirect Muscle Disorders/Injuries in Elite Football Players.

BACKGROUND: The aim of this study was to investigate the association between MCT1 rs1049434 polymorphism and indirect muscle injuries in elite football players. One hundred and seventy-three male elite Italian football players (age = 19.2 ± 5.3 years) were recruited from a first-league football club participating at the Official National Italian Football Championship (Serie A, Primavera, Allievi, Giovanissimi). The cohort was genotyped for the MCT1 rs1049434 polymorphism, and muscle injuries data were collected during the period of 2009-2014 (five football seasons). METHODS: Genomic DNA was extracted using a buccal swab, and genotyping was performed using PCR method. Structural-mechanical injuries and functional muscle disorder were included in the acute indirect muscle injury group. RESULTS: Participants with the MCT1 AA (AA = 1.57 ± 3.07, n = 69) genotype exhibit significantly higher injury incidents compared to participants with the TT genotype (TT = 0.09 ± 0.25, n = 22, P = 0.04). CONCLUSIONS: The MCT1 rs1049434 polymorphism is associated with the incidence of muscle injuries in elite football players. We anticipate that the knowledge of athletes' genetic predisposition to sports-related injuries might aid in individualizing training programs.

Vitamin D receptor gene polymorphisms and musculoskeletal injuries in professional football players.

The aim of the present study was to investigate the association between vitamin D receptor (VDR) gene polymorphisms and musculoskeletal injury (MI) in elite football players. In total, 54 male professional football players were recruited from an official Italian professional championship team between 2009 and 2013. The cohort was genotyped for the ApaI, BsmI and FokI polymorphisms and MI data were collected over four football seasons. No significant differences were identified among the genotypes in the incidence rates or severity of MI (P=0.254). In addition, no significant associations were observed between VDR polymorphisms and MI phenotypes (P=0.460). However, the results of the casewise multiple regression analysis indicated that the ApaI genotypes accounted for 18% of injury severity (P=0.002). Therefore, while the BsmI and FokI polymorphisms did not appear to be associated with the severity or incidence of MI, the ApaI genotypes may have influenced the severity of muscle injury in top-level football players.

Relationship between static and dynamic balance abilities in Italian professional and youth league soccer players.

OBJECTIVES: To assess the existence of correlations between static and dynamic balance abilities in young and professional elite soccer players. DESIGN: Cross-sectional. PARTICIPANTS: Fifty-one elite players who regularly compete at national level divided into two groups: Professional (age 18-34, n = 20) and Under 15-17 (age 14-16, n = 31). MAIN OUTCOME MEASURES: Dynamic balance was assessed for the case of a single-leg landing task by means of vertical time to stabilization (TTS) and postural sway calculated on the basis of center-of-pressure (COP) trajectories (sway area, COP displacements in antero-posterior and medio-lateral direction, COP path length). The same parameters were also measured for a 20 s one-legged stance to assess static balance abilities. RESULTS: No significant correlations were found between static and dynamic balance parameters except for TTS and COP displacements in the antero-posterior direction (r = 0.29, p = 0.003). Professional players are characterized by lower TTS in comparison with youth leagues players (0.767 vs. 1.188 s for the dominant limb, p < 0.001) and exhibit reduced sway area (of 34-40%, p < 0.05) for both conditions tested. CONCLUSION: The assessment of balance in soccer players should be performed with both dynamic and static tests, considering that the postural control performances in the two cases are not related.

ACTN3 R577X polymorphism is not associated with team sport athletic status in Italians.

BACKGROUND: The ACTN3 gene may influence performance in team sports, in which sprint action and high-speed movements, regulated by the anaerobic energy system, are crucial to the ultimate success of a match. The aim of this study was to determine the association between the ACTN3 R577X (rs1815739) polymorphism and elite team sport athletic status in Italian male athletes. METHODS: We compared the genotype and allele frequency of the ACTN3 R577X polymorphism between team sport athletes (n = 75), endurance athletes (n = 40), sprint/power athletes (n = 64), and non-athletic healthy controls (n = 192) from Italy. Genomic DNA was collected using a buccal swab. Extraction was performed according to the manufacturer's directions provided with a commercially available kit (Qiagen S.r.l., Milan, Italy). RESULTS: Team sport athletes showed a lower frequency of the 577RR genotype compared to the 577XX genotype than sprint/power athletes (p = 0.044). However, the ACTN3 R577X polymorphism was not associated with team sport athletic status compared to endurance athletes and non-athletic controls. CONCLUSIONS: Our results agree with a recent large-scale study involving athletes from Spain, Poland, and Russia. The ACTN3 R577X polymorphism was not associated with team sport athletic status compared to endurance athletes and non-athletic controls.

Characterization of static balance abilities in elite soccer players by playing position and age.

In this study, we investigated the static balance of adult and adolescent elite soccer players to understand how expertise and playing position influence postural control. Seventy-one national level players were tested using a force platform to acquire Center-of-Pressure (COP) data in uni- and bipedal stance and calculate sway area (SA), COP path length, velocity and displacements. The results show significant differences in postural sway related to age and playing position only for single-limb stance. In particular, midfielders exhibited significantly lower values of SA with respect to defenders (-48%, p = 0.001) and the under-15 players exhibited SA 42-64% higher than all the others (p = 0.001). In the light of planning training or rehabilitation programs specific for each player's role and age, sway measurements may supply useful, objective and reliable information only for the unipedal test as the bipedal standing appears not challenging enough to let differences in balance abilities emerge.

Exercise training, lymphocyte subsets and their cytokines production: experience of an Italian professional football team and their impact on allergy.

BACKGROUND: In recent years, numerous articles have attempted to shed light on our understanding of the pathophysiological mechanisms of exercise-induced immunologic changes and their impact on allergy and asthma. It is known that lymphocyte subclasses, cytokines, and chemokines show modifications after exercise, but outcomes can be affected by the type of exercise as well as by its intensity and duration. Interesting data have been presented in many recent studies on mouse models, but few studies on humans have been performed to check the long-term effects of exercise over a whole championship season. METHODS: This study evaluated lymphocyte subsets and their intracellular IL-2, IL-4, TNF-α, and IFN-γ production in professional football (soccer) players, at three stages of the season, to evaluate if alterations occur, particularly in relation to their allergic status. RESULTS AND CONCLUSION: Despite significant mid-season alterations, no significant lymphocyte subclasses count modifications, except for NKs that were significantly higher, were observed at the end. IL-2 and IL-4 producing cells showed a significant decrease (P = 0.018 and P = 0.001, but in a steady fashion for IL-4), confirming the murine data about the potential beneficial effects of aerobic exercise for allergic asthma.

New genetic model for predicting phenotype traits in sports.

PURPOSE: The aim of the current study was to construct a genetic model with a new algorithm for predicting athletic-performance variability based on genetic variations. METHODS: The influence of 6 polymorphisms (ACE, ACTN-3, BDKRB2, VDR-ApaI, VDR-BsmI, and VDR-FokI) on vertical jump was studied in top-level male Italian soccer players (n = 90). First, the authors calculated the traditional total genotype score and then determined the total weighting genotype score (TWGS), which accounts for the proportion of significant phenotypic variance predicted by the polymorphisms. Genomic DNA was extracted from saliva samples using a standard protocol. Genotyping was performed using polymerase chain reaction (PCR). RESULTS: The results obtained from the new genetic model (TWGS) showed that only 3 polymorphisms entered the regression equation (ACTN-3, ACE, and BDKRB2), and these polymorphisms explained 17.68-24.24% of the vertical-jump variance. With the weighting given to each polymorphism, it may be possible to identify a polygenic profile that more accurately explains, at least in part, the individual variance of athletic-performance traits. CONCLUSIONS: This model may be used to create individualized training programs based on a player's genetic predispositions, as well as to identify athletes who need an adapted training routine to account for individual susceptibility to injury.