Chronic traumatic encephalopathy: how serious a sports problem is it?

Neuroanatomical correlates of aggressiveness: a case-control voxel- and surface-based morphometric study

Aggression occurs across the population ranging on a symptom continuum. Most previous studies have used magnetic resonance imaging in clinical/forensic samples, which is associated with several confounding factors. The present study examined structural brain characteristics in two healthy samples differing only in their propensity for aggressive behavior. Voxel- and surface-based morphometry (SBM) analyses were performed on 29 male martial artists and 32 age-matched male controls. Martial artists had significantly increased mean gray matter volume in two frontal (left superior frontal gyrus and bilateral anterior cingulate cortex) and one parietal (bilateral posterior cingulate gyrus and precuneus) brain clusters compared to controls (whole brain: p < 0.001, cluster level: family-wise error (FWE)-corrected). SBM analyses revealed a trend for greater gyrification indices in martial artists compared to controls in the left lateral orbital frontal cortex and the left pars orbitalis (whole brain: p < 0.001, cluster level: FWE-corrected). The results indicate brain structural differences between martial artists and controls in frontal and parietal brain areas critical for emotion processing/inhibition of emotions as well as empathic processes. The present study highlights the importance of studying healthy subjects with a propensity for aggressive behavior in future structural MRI research on aggression.

GABAergic circuits of the basolateral amygdala and generation of anxiety after traumatic brain injury

Traumatic brain injury (TBI) has reached epidemic proportions around the world and is a major public health concern in the United States. Approximately 2.8 million individuals sustain a traumatic brain injury and are treated in an Emergency Department yearly in the U.S., and about 50,000 of them die. Persistent symptoms develop in 10-15% of the cases including neuropsychiatric disorders. Anxiety is the second most common neuropsychiatric disorder that develops in those with persistent neuropsychiatric symptoms after TBI. Abnormalities or atrophy in the temporal lobe has been shown in the overwhelming number of TBI cases. The basolateral amygdala (BLA), a temporal lobe structure that consolidates, stores and generates fear and anxiety-based behavioral outputs, is a critical brain region in the anxiety circuitry. In this review, we sought to capture studies that characterized the relationship between human post-traumatic anxiety and structural/functional alterations in the amygdala. We compared the human findings with results obtained with a reproducible mild TBI animal model that demonstrated a direct relationship between the alterations in the BLA and an anxiety-like phenotype. From this analysis, both preliminary insights, and gaps in knowledge, have emerged which may open new directions for the development of rational and more efficacious treatments.

Head injury in mixed martial arts: a review of epidemiology, affected brain structures and risks of cognitive decline

Background: The popularity trend of mixed martial arts (MMA) is steeply increasing, especially in the very young population. Unfortunately, MMA carries an enormous risk of head trauma.Purpose: The aim of this article is to provide review of studies on the association between head injuries and cognitive functions in MMA fighters.Methods: A systematic literature review was performed. Web of Science, PubMed, Springer, and Scopus databases were used. A total of 30 studies were identified. The inclusion criteria were as follows: studies with MMA fighters and head injuries and/or TKO/KO and/or reduction of cognitive functions in these fighters.Results: The results indicate that the incidence of head traumas ranges between 58% and 78% of all injuries. The King-Devick test seems to be a suitable rapid tool used in the studies to assess the extent of cognitive impairment. Among the detected studies, the post-fighting scores were significantly worse for fighters with head trauma during the match. We also found anomalies in MMA fighters in different brain structures, but it seems that the thalamus and caudate are the most affected. The impaired performance in processing speed, verbal memory and psychomotor speed is regularly confirmed in studies with MMA fighters. In addition, head traumatization seems to be a risk factor for the development of neurodegenerative disorders and it may be one of the possible causes of chronic traumatic encephalopathy (CTE). Several global medical societies have identified MMA as a violent and dangerous sport and have called for its ban - but unsuccessfully.Conclusion: Therefore, possible recommendations should include increased medical supervision of the fighter (during his career, but also after it) and the introduction of practical safety instructions for fighters to reduce the risk of developing CTE. With the increasing popularity of MMA, the risk of CTE should not be underestimated.

Comprehensive Neuropsychiatric and Cognitive Characterization of Former Professional Football Players: Implications for Neurorehabilitation

Objectives: To identify novel targets for neurorehabilitation of people with a remote history of multiple concussions by: (1) comprehensively characterizing neuropsychiatric and cognitive functioning in former professional football players, with a focus on executive functions; (2) distinguishing concussion-related findings from pre-morbid/cohort characteristics of professional football players; and, (3) exploring the relationship between executive functions and neuropsychiatric symptoms. Participants: Sixty-one high-functioning former professional football players and 31 age- and sex-matched control participants without history of concussion or participation in contact sports. Design: Between-groups analyses. Main measures: Neuropsychiatric. Personality Assessment Inventory (PAI) clinical scales plus the Aggression treatment consideration scale; the Mini International Neuropsychiatric Interview (MINI). Cognitive. Comprehensive clinical neuropsychological battery assessing domains of verbal and visuospatial attention; speed of processing and memory; current and estimated pre-morbid IQ; and, executive functioning, including two experimental measures that were novel for this population (i.e., response inhibition and inconsistency of responding on a go/no-go task). Results: (1) Compared to control participants, former professional football players scored significantly higher on the PAI Depression, Mania, and Aggression scales, and significantly lower on response inhibition. (2) Relative to controls, former players with >3 concussions (x ¯ = 6 . 1 ), but not former players with ≤ 3 concussions (x ¯ = 2 . 0 ), showed (i) significantly higher scores on the PAI Depression scale, (ii) significantly more MINI clinical diagnoses overall, and manic/hypomanic episodes specifically, and (iii) significantly poorer executive function. (3) Mediation analysis revealed that concussion exposure had a significant indirect effect on PAI Depression, Mania, and Aggression via inconsistency of responding on the go/no-go task. Conclusions: Notable impairments to neuropsychiatric functioning and worse performance on a sensitive experimental measure of executive function were observed; these were related to both concussion history and pre-morbid (cohort) factors. Therefore, neuropsychiatric and executive functioning should be carefully assessed in those with a remote history of multiple concussions. Moreover, former players' neuropsychiatric symptoms were associated with inconsistency of responding; this suggests that treatments targeted at response inconsistency could help to mitigate neuropsychiatric dysfunction.

Chronic Traumatic Encephalopathy in Professional American Football Players: Where Are We Now?

Repetitive head trauma provides a favorable milieu for the onset of inflammatory and neurodegenerative processes. The result of long-lasting head trauma is chronic traumatic encephalopathy (CTE), a disease process well-recognized in boxers, military personnel, and more recently, in American football players. CTE is a chronic neurodegenerative disease with hallmarks of hyperphosphorylated tau (p-tau) aggregates and intercellular lesions of neurofibrillary tangles. The criteria for CTE diagnosis requires at least 1-2 focal perivascular lesions of p-tau in the cerebral cortex, at the depth of the sulci. These pathognomonic lesions aggregate within neurons and glial cells such as astrocytes, and cell processes within the vicinity of small blood vessels. CTE presents in a distinct topographical distribution pattern compared to other tauopathies such as AD and other age-related astrogliopathies. CTE also has an insidious onset, years after repetitive head trauma. The disease course of CTE is characterized by cognitive dysfunction, behavioral changes, and can progress to altered motor function with parkinsonian-like manifestations in later stages. This short review aims to summarize CTE in professional football, epidemiology, diagnosis based on neuroanatomical abnormalities, cognitive degeneration, and adverse mental health effects, as well as gaps in the literature and future directions in diagnostics, therapeutics, and preventive measures.

Reduced brain glutamine in female varsity rugby athletes after concussion and in non-concussed athletes after a season of play

The purpose of this study was to use non-invasive proton magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) to monitor changes in prefrontal white matter metabolite levels and tissue microstructure in female rugby players with and without concussion (ages 18-23, n = 64). Evaluations including clinical tests and 3 T MRI were performed at the beginning of a season (in-season) and followed up at the end of the season (off-season). Concussed athletes were additionally evaluated 24-72 hr (n = 14), three months (n = 11), and six months (n = 8) post-concussion. Reduced glutamine at 24-72 hr and three months post-concussion, and reduced glutamine/creatine at three months post-concussion were observed. In non-concussed athletes (n = 46) both glutamine and glutamine/creatine were lower in the off-season compared to in-season. Within the MRS voxel, an increase in fractional anisotropy (FA) and decrease in radial diffusivity (RD) were also observed in the non-concussed athletes, and correlated with changes in glutamine and glutamine/creatine. Decreases in glutamine and glutamine/creatine suggest reduced oxidative metabolism. Changes in FA and RD may indicate neuroinflammation or re-myelination. The observed changes did not correlate with clinical test scores suggesting these imaging metrics may be more sensitive to brain injury and could aid in assessing recovery of brain injury from concussion.

A Review of Sport-Related Head Injuries

We review current topics in sport-related head injuries including acute subdural hematoma (ASDH), traumatic cerebrovascular disease, cerebral concussion, and chronic traumatic encephalopathy (CTE). Sports-related ASDH is a leading cause of death and severe morbidity in popular contact sports like American football and Japanese judo. Rotational acceleration can cause either cerebral concussion or ASDH due to rupture of a parasagittal bridging vein. Although rare, approximately 80% of patients with cerebral infarction due to sport participation are diagnosed with ischemia or infarction due to arterial dissection. Computed tomography angiography, magnetic resonance angiography, and ultrasound are useful for diagnosing arterial dissection; ultrasound is particularly useful for detecting dissection of the common and internal carotid arteries. Repeated sports head injuries increase the risks of future concussion, cerebral swelling, ASDH, and CTE. To avoid fatal consequences of CTE, it is essential to understand the criteria for safe post-concussion sports participation. Once diagnosed with a concussion, an athlete should not be allowed to return to play on the same day and should not resume sports before the concussion symptoms have completely resolved. Information about the risks and management of head injuries in different sports should be widely disseminated in educational institutions and by sport organization public relations campaigns.

Retirement-from-sport considerations following pediatric sports-related concussion: case illustrations and institutional approach

The decision to advise an athlete to retire from sports following sports-related concussion (SRC) remains a persistent challenge for physicians. In the absence of strong empirical evidence to support recommendations, clinical decision making must be individualized and should involve a multidisciplinary team of experts in concussion and traumatic brain injury. Although previous authors have advocated for a more conservative approach to these issues in child and adolescent athletes, there are few reports outlining considerations for this process among this unique population. Here, the authors use multiple case illustrations to discuss 3 subgroups of clinical considerations for sports retirement among pediatric SRC patients including the following: those with structural brain abnormalities identified on neuroimaging, those presenting with focal neurological deficits and abnormalities on physical examination, and those in whom the cumulative or prolonged effects of concussion are suspected or demonstrated. The authors' evolving multidisciplinary institutional approach to return-to-play and retirement decision making in pediatric SRC is also presented.

The science and questions surrounding chronic traumatic encephalopathy

Recently, the pathobiology, causes, associated factors, incidence and prevalence, and natural history of chronic traumatic encephalopathy (CTE) have been debated. Data from retrospective case series and high-profile media reports have fueled public fear and affected the medical community's understanding of the role of sports-related traumatic brain injury (TBI) in the development of CTE. There are a number of limitations posed by the current evidence that can lead to confusion within the public and scientific community. In this paper, the authors address common questions surrounding the science of CTE and propose future research directions.

Chronic Traumatic Encephalopathy and Movement Disorders: Update

Association of repetitive brain trauma with progressive neurological deterioration has been described since the 1920s. Punch drunk syndrome and dementia pugilistica (DP) were introduced first to explain symptoms in boxers, and more recently, chronic traumatic encephalopathy (CTE) has been used to describe a neurodegenerative disease in athletes and military personal with a history of multiple concussions. Although there are many similarities between DP and CTE, a number of key differences are apparent especially when comparing movement impairments. The aim of this review is to compare clinical and pathological aspects of DP and CTE with a focus on disorders of movement.

Postconcussion syndrome: demographics and predictors in 221 patients

OBJECTIVE The objective of this study was to determine the demographics and predictors of postconcussion syndrome (PCS) in a large series of patients using a novel definition of PCS. METHODS The authors conducted a retrospective cohort study of 284 consecutive concussed patients, 221 of whom had PCS on the basis of at least 3 symptoms persisting at least 1 month. This definition of PCS was uniformly employed and is unique in accepting an expanded list of symptoms, in shortening the postconcussion interval to 1 month from 3 months, and in excluding those with focal injuries such as hemorrhages and contusions. RESULTS The 221 cases showed considerable heterogeneity in clinical features of PCS. They averaged 3.3 concussions, with a range of 0 to 12 or more concussions, and 62.4% occurred during sports and recreation. The median duration of PCS was 7 months at the time of examination, with 11.8% lasting more than 2 years, and 23.1% with PCS had only 1 concussion. The average patient age was 27 years (range 10-74 years). The average number of persistent symptoms was 8.1; 26.2% had a previous psychiatric condition, attention-deficit disorder/attention-deficit hyperactivity disorder, a learning disability, or previous migraine headaches. The prevalence of arachnoid cysts and Chiari malformation in PCS exceeded the general population. Additionally, involvement in litigation, presence of extracranial injuries, amnesia and/or loss of consciousness, and female sex were predictive of reporting a high number of symptoms. A prior history of psychiatric conditions or migraines, cause of injury, number of previous concussions, and age did not significantly predict symptom number. Only the number of symptoms reported predicted the duration of PCS. To predict the number of symptoms for those who fulfilled PCS criteria according to the International Classification of Diseases, 10th Revision (ICD-10), and the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV), the number of previous concussions was significant. CONCLUSIONS PCS is commonly associated with multiple concussions, but 23.1% in the present series occurred after only 1 concussion. Most patients with PCS had multiple symptoms persisting for months or years. The median duration of PCS was 7 months, with a range up to 26 years. In only 11.3%, the PCS had ended at the time of consultation. Not all predictors commonly cited in the literature align with the findings in this study. This is likely due to differences in the definitions of PCS used in research. These results suggest that the use of ICD-10 and DSM-IV to diagnose PCS may be biased toward those who are vulnerable to concussions or with more severe forms of PCS. It is thus important to redefine PCS based on evidence-based medicine.

Diagnosis and management of paediatric concussion

Heightened recognition of concussions and concerns about their sequelae in children has become an increasing community and public health concern. Biomarkers and clinical tests are being explored, but the diagnosis of concussion in the emergency department continues to be based on clinical signs and symptoms. While the majority of children go on to recover from post-concussive symptoms within 2 weeks, it is unclear which patients with concussion will go on to develop short- or long-term sequelae. A number of more or less evidence-based guidelines have become available which seek to guide clinicians on how to manage children post-concussion. In general, care after the emergency department is focused on reducing the risk of re-injury and rest until cerebral recovery with a graduated return to school and then play.

Sport-Related Concussion Reporting and State Legislative Effects

OBJECTIVE

To investigate concussion rates and reporting frequencies in high school and collegiate athletes in 2013, compare results to those obtained from 1999 to 2002, and examine to what extent the 2012 Wisconsin state concussion law affected reporting in 2013.

DESIGN

Retrospective 2013 survey compared with prior survey.

SETTING

High schools and colleges in the Milwaukee, Wisconsin, area.

PARTICIPANTS

Athletes (N = 784) from multiple sports were surveyed in 2013. Football players (N = 1532) from 1999 to 2002 completed the same measure.

MAIN OUTCOME MEASURES

Both surveys assessed concussion history, concussion incidence during the current season, whether incident concussions were reported, who concussions were reported to, and reasons for not reporting. The 2013 survey also assessed awareness of the Wisconsin state law and its effect on reporting.

RESULTS

Rates of concussion in the surveyed season were comparable to previous findings from 1999 to 2002 (16.6% vs 15.3%, P = 0.558). Notably, athletes were significantly more likely to report their concussions in 2013 (70.6% vs 47.3% previously, P = 0.011). Among high school athletes surveyed, 59.5% were aware of the Wisconsin state law, with 55.1% stating it would make them more likely to report a concussion.

CONCLUSIONS

Rates of concussion for 1 sport season have not changed significantly over the past 14 years. The percentage of concussions that are reported to someone has increased significantly. Awareness of the Wisconsin state law does not fully account for the increase in concussion reporting.

CLINICAL RELEVANCE

Given the finite amount of knowledge regarding the influence of concussion-related cultural and legal changes, these findings will help to inform clinicians of the current concussion milieu from the perspective of athletes. It will inform practitioners involved in concussion management to what extent athletes are aware of and report concussions.

Psychiatric outcomes after pediatric sports-related concussion

OBJECT

The objectives of this study were twofold: (1) to examine the prevalence of emotional symptoms among children and adolescents with a sports-related concussion (SRC) who were referred to a multidisciplinary pediatric concussion program and (2) to examine the prevalence, clinical features, risk factors, and management of postinjury psychiatric outcomes among those in this clinical population.

METHODS

The authors conducted a retrospective chart review of all patients with SRC referred to a multidisciplinary pediatric concussion program between September 2013 and October 2014. Clinical assessments carried out by a single neurosurgeon included clinical history, physical examination, and Post-Concussion Symptom Scale (PCSS) scoring. Postinjury psychiatric outcomes were defined as a subjective worsening of symptoms of a preinjury psychiatric disorder or new and isolated suicidal ideation or diagnosis of a novel psychiatric disorder (NPD). An NPD was defined as a newly diagnosed psychiatric disorder that occurred in a patient with or without a lifetime preinjury psychiatric disorder after a concussion. Clinical resources, therapeutic interventions, and clinical and return-to-play outcomes are summarized.

RESULTS

One hundred seventy-four patients (mean age 14.2 years, 61.5% male) were included in the study. At least 1 emotional symptom was reported in 49.4% of the patients, and the median emotional PCSS subscore was 4 (interquartile range 1-8) among those who reported at least 1 emotional symptom. Overall, 20 (11.5%) of the patients met the study criteria for a postinjury psychiatric outcome, including 14 patients with an NPD, 2 patients with isolated suicidal ideation, and 4 patients with worsening symptoms of a preinjury psychiatric disorder. Female sex, a higher initial PCSS score, a higher emotional PCSS subscore, presence of a preinjury psychiatric history, and presence of a family history of psychiatric illness were significantly associated with postinjury psychiatric outcomes. Interventions for patients with postinjury psychiatric outcomes included pharmacological therapy alone in 2 patients (10%), cognitive behavioral therapy alone in 4 (20%), multimodal therapy in 9 (45%), and no treatment in 5 (25%). Overall, 5 (25%) of the patients with postinjury psychiatric disorders were medically cleared to return to full sports participation, whereas 5 (25%) were lost to follow-up and 9 (45%) remained in treatment by the multidisciplinary concussion program at the end of the study period. One patient who was asymptomatic at the time of initial consultation committed suicide.

CONCLUSIONS

Emotional symptoms were commonly reported among pediatric patients with SRC referred to a multidisciplinary pediatric concussion program. In some cases, these symptoms contributed to the development of an NPD, isolated suicidal ideation, and worsening symptoms of a preexisting psychiatric disorder. Future research is needed to clarify the prevalence, pathophysiology, risk factors, and evidence-based management of postinjury psychiatric outcomes after pediatric SRC. Successful management of these patients requires prompt recognition and multidisciplinary care by experts with clinical training and experience in concussion and psychiatry.

Tackling in Youth Football

American football remains one of the most popular sports for young athletes. The injuries sustained during football, especially those to the head and neck, have been a topic of intense interest recently in both the public media and medical literature. The recognition of these injuries and the potential for long-term sequelae have led some physicians to call for a reduction in the number of contact practices, a postponement of tackling until a certain age, and even a ban on high school football. This statement reviews the literature regarding injuries in football, particularly those of the head and neck, the relationship between tackling and football-related injuries, and the potential effects of limiting or delaying tackling on injury risk.

Neuroimaging assessment of early and late neurobiological sequelae of traumatic brain injury: implications for CTE

Traumatic brain injury (TBI) has been increasingly accepted as a major external risk factor for neurodegenerative morbidity and mortality. Recent evidence indicates that the resultant chronic neurobiological sequelae following head trauma may, at least in part, contribute to a pathologically distinct disease known as Chronic Traumatic Encephalopathy (CTE). The clinical manifestation of CTE is variable, but the symptoms of this progressive disease include impaired memory and cognition, affective disorders (i.e., impulsivity, aggression, depression, suicidality, etc.), and diminished motor control. Notably, mounting evidence suggests that the pathology contributing to CTE may be caused by repetitive exposure to subconcussive hits to the head, even in those with no history of a clinically evident head injury. Given the millions of athletes and military personnel with potential exposure to repetitive subconcussive insults and TBI, CTE represents an important public health issue. However, the incidence rates and pathological mechanisms are still largely unknown, primarily due to the fact that there is no in vivo diagnostic tool. The primary objective of this manuscript is to address this limitation and discuss potential neuroimaging modalities that may be capable of diagnosing CTE in vivo through the detection of tau and other known pathological features. Additionally, we will discuss the challenges of TBI research, outline the known pathology of CTE (with an emphasis on Tau), review current neuroimaging modalities to assess the potential routes for in vivo diagnosis, and discuss the future directions of CTE research.

Frontotemporal correlates of impulsivity and machine learning in retired professional athletes with a history of multiple concussions

The frontotemporal cortical network is associated with behaviours such as impulsivity and aggression. The health of the uncinate fasciculus (UF) that connects the orbitofrontal cortex (OFC) with the anterior temporal lobe (ATL) may be a crucial determinant of behavioural regulation. Behavioural changes can emerge after repeated concussion and thus we used MRI to examine the UF and connected gray matter as it relates to impulsivity and aggression in retired professional football players who had sustained multiple concussions. Behaviourally, athletes had faster reaction times and an increased error rate on a go/no-go task, and increased aggression and mania compared to controls. MRI revealed that the athletes had (1) cortical thinning of the ATL, (2) negative correlations of OFC thickness with aggression and task errors, indicative of impulsivity, (3) negative correlations of UF axial diffusivity with error rates and aggression, and (4) elevated resting-state functional connectivity between the ATL and OFC. Using machine learning, we found that UF diffusion imaging differentiates athletes from healthy controls with significant classifiers based on UF mean and radial diffusivity showing 79–84 % sensitivity and specificity, and 0.8 areas under the ROC curves. The spatial pattern of classifier weights revealed hot spots at the orbitofrontal and temporal ends of the UF. These data implicate the UF system in the pathological outcomes of repeated concussion as they relate to impulsive behaviour. Furthermore, a support vector machine has potential utility in the general assessment and diagnosis of brain abnormalities following concussion.

Repeated head trauma is associated with smaller thalamic volumes and slower processing speed: the Professional Fighters' Brain Health Study

Objectives

Cumulative head trauma may alter brain structure and function. We explored the relationship between exposure variables, cognition and MRI brain structural measures in a cohort of professional combatants.

Methods

224 fighters (131 mixed martial arts fighters and 93 boxers) participating in the Professional Fighters Brain Health Study, a longitudinal cohort study of licensed professional combatants, were recruited, as were 22 controls. Each participant underwent computerised cognitive testing and volumetric brain MRI. Fighting history including years of fighting and fights per year was obtained from self-report and published records. Statistical analyses of the baseline evaluations were applied cross-sectionally to determine the relationship between fight exposure variables and volumes of the hippocampus, amygdala, thalamus, caudate, putamen. Moreover, the relationship between exposure and brain volumes with cognitive function was assessed.

Results

Increasing exposure to repetitive head trauma measured by number of professional fights, years of fighting, or a Fight Exposure Score (FES) was associated with lower brain volumes, particularly the thalamus and caudate. In addition, speed of processing decreased with decreased thalamic volumes and with increasing fight exposure. Higher scores on a FES used to reflect exposure to repetitive head trauma were associated with greater likelihood of having cognitive impairment.

Conclusions

Greater exposure to repetitive head trauma is associated with lower brain volumes and lower processing speed in active professional fighters.

All-cause and disease-specific mortality among male, former elite athletes: an average 50-year follow-up

AIM

To investigate life expectancy and mortality among former elite athletes and controls.

METHODS

HR analysis of cause-specific deaths sourced from the national death registry for former Finnish male endurance, team and power sports athletes (N=2363) and controls (N=1657). The median follow-up time was 50 years.

RESULTS

Median life expectancy was higher in the endurance (79.1 years, 95% CI 76.6 to 80.6) and team (78.8, 78.1 to 79.8) sports athletes than in controls (72.9, 71.8 to 74.3). Compared to controls, risk for total mortality adjusted for socioeconomic status and birth cohort was lower in the endurance ((HR 0.70, 95% CI 0.61 to 0.79)) and team (0.80, 0.72 to 0.89) sports athletes, and slightly lower in the power sports athletes (0.93, 0.85 to 1.03). HR for ischaemic heart disease mortality was lower in the endurance (0.68, 0.54 to 0.86) and team sports (0.73, 0.60 to 0.89) athletes. HR for stroke mortality was 0.52 (0.33 to 0.83) in the endurance and 0.59 (0.40 to 0.88) in the team sports athletes. Compared to controls, the risk for smoking-related cancer mortality was lower in the endurance (HR 0.20, 0.08 to 0.47) and power sports (0.40, 0.25 to 0.66) athletes. For dementia mortality, the power sports athletes, particularly boxers, had increased risk (HR 4.20, 2.30 to 7.81).

CONCLUSIONS

Elite athletes have 5-6 years additional life expectancy when compared to men who were healthy as young adults. Lower mortality for cardiovascular disease was in part due to lower rates of smoking, as tobacco-related cancer mortality was especially low.