Key points What is the association between participation in organized American football and the odds of having a reported diagnosis of parkinsonism or Parkinson’s disease (PD)? Findings In this cross-sectional study that leveraged data from the Fox Insight online study , 729 participants with a history of playing organized American football were more likely to have a diagnosis of parkinsonism or Parkinson’s disease (PD) compared to participants in other organized sports. Longer game duration and higher level of soccer play were associated with higher odds of a reported diagnosis. Meaning The findings suggest that participation in American football could be a risk factor for developing parkinsonism or Parkinson’s disease (PD). |
Identification of risk factors for Parkinson’s disease (PD) is essential for early detection and diagnosis. Age and male sex are known demographic risk factors for PD. Genetic and environmental risk factors include a family history of PD and exposure to toxins and pesticides. There are other proposed etiologies for parkinsonism, such as vascular parkinsonism caused by cerebrovascular disease in association with vascular risk factors (e.g., diabetes and hypertension).
Traumatic brain injury ( TBI) is another risk factor for PD, as observed in non-human TBI models and autopsy studies. Crane et al analyzed TBI data from 7,130 participants from 3 large prospective cohort studies: the Adult Changes in Thought (ACT) study, the Religious Orders Study (ROS), and the Memory and Aging Project (MAP), and found an association between TBI with loss of consciousness and parkinsonism symptoms among participants in the ROS and MAP cohorts.
Exposure to repetitive head impacts occurs through participation in contact sports , such as football, boxing, soccer, and ice hockey, as well as military service and other activities. Exposure to repetitive impacts to the head is the main risk factor for chronic traumatic encephalopathy (neurodegenerative tauopathy) . Chronic traumatic encephalopathy has been diagnosed pathologically in former football, soccer, ice hockey and rugby players. There is a dose-response association between the duration of soccer and the risk of chronic traumatic encephalopathy.
Age at first exposure to football has been shown to contribute to long-term neurobehavioral symptoms, but not risk of chronic traumatic encephalopathy, in symptomatic older people. However, the literature on age of first exposure to football is mixed. Exposure to repetitive head impacts has also been associated with Lewy body pathology and may be an independent risk factor for parkinsonism and PD. Parkinsonism has been observed in boxers. A mortality study found an increased risk of death from PE in 3,439 former National Football League players who played between 1959 and 1988.
Research on the association between American football participation and parkinsonism and PD is scarce, limited by secondary reports and the lack of an appropriate comparison group. Large studies with appropriate reference groups testing the association between football participation and parkinsonism or PD are a critical next step. Here, we leveraged 1,875 male participants from the Fox Insight study to assess the association between American football participation and the odds of having a diagnosis of parkinsonism or PD.
Importance
Parkinsonism and Parkinson’s disease (PD) are known to result from repetitive impacts to the head from boxing. Repetitive head impacts from American football may also be associated with an increased risk of neurodegenerative pathologies causing parkinsonism, however, in vivo research on the association between football and PD is scarce and limited by small samples and equivocal findings. .
Aim
To assess the association between football participation and self-reported diagnosis of parkinsonism or Parkinson’s disease (PD).
Design, environment and participants
This cross-sectional study leveraged data from the Fox Insight online study . Participants completed online questionnaires and self-reported whether they currently had a diagnosis of Parkinson’s disease or parkinsonism from a doctor or other health care professional.
In November 2020, the Boston University Head Impact Exposure Assessment was launched to collect data on repetitive head impacts. Data used for this manuscript were obtained from the Fox Insight database on June 9, 2022. A total of 1875 men who endorsed playing any organized sport were included. The former athletes were divided into those who played American football (n = 729 [38.9%]) and those who played other sports (reference group).
Exhibitions
Self-reported participation in American football, duration and level of football play, age at first exposure.
Main results and measures
Logistic regression assessed associations between Parkinson’s disease (PD) status and soccer playing history, duration of soccer playing, highest level played, and age at first exposure, controlling for age, education, history of diabetes or heart disease, body mass index, history of traumatic brain injury with loss of consciousness, and family history of PD.
Results
In this sample of 1875 men (mean [SD] age, 67.69 [9.84] years) enriched with parkinsonism or Parkinson’s disease (PD) data (n = 1602 [85.4%]), 729 (38 .9%) played soccer (mean duration [SD], 4.35 [2.91] years).
A history of playing soccer was associated with higher odds of having a diagnosis of parkinsonism or PD (odds ratio [OR], 1.61; 95% CI, 1.19-2.17).
Among the entire sample, longer duration of gaming was associated with higher odds of having a diagnosis of parkinsonism or PD (OR, 1.12; 95% CI, 1.06-1.19).
Among soccer players, longer duration of soccer play (OR, 1.12; 95% CI, 1.02-1.23) and higher level of play (OR, 2.93; 95% CI, 1.02-1.23) 95%, 1.28-6.73) were associated with increased odds of having parkinsonism or PD.
Figure : Estimated marginal mean differences in soccer game duration by Parkinson’s disease or parkinsonism status . The figure was generated using a multivariate analysis of covariance comparing the parkinsonism/Parkinson’s disease and non-parkinsonism/Parkinson’s disease groups on duration of soccer play, controlling for age, education level, disease history cardiac, history of diabetes, family history of Parkinson’s disease, traumatic brain injury with loss of consciousness, and body mass index. The estimated marginal mean difference in soccer game duration for the given outcome between the groups is reported and shown on the y-axis. Error bars are 95% CIs.
Conclusions and relevance
In this cross-sectional study of PD-enriched participants, participation in American football was associated with increased odds of having a reported diagnosis of parkinsonism or Parkinson’s disease (PD).
Final message In this cross-sectional study, there was an association between American football participation and increased odds of self-reported parkinsonism or Parkinson’s disease (PD). Among soccer players, the odds of having a diagnosis of parkinsonism or PD were higher with more seasons and a higher level of soccer play. The findings suggest that participation in American football could be a risk factor for developing parkinsonism or PD. Prospective research among community samples objectively assessing parkinsonism and PD in former American football players at different levels of play will clarify the observed associations. |
