American Football Play and Parkinson Disease Among Men

Abstract

ImportanceParkinsonism and Parkinson disease (PD) are known to result from repetitive head impacts from boxing. Repetitive head impacts from American football may also be associated with increased risk of neurodegenerative pathologies that cause parkinsonism, yet in vivo research on the association between football play and PD is scarce and limited by small samples and equivocal findings.ObjectiveTo evaluate the association between football participation and self-reported parkinsonism or PD diagnosis.Design, Setting, and ParticipantsThis cross-sectional study leveraged data from the online Fox Insight study. Participants completed online questionnaires and self-reported whether they currently had a diagnosis of Parkinson disease or parkinsonism by a physician or other health care professional. In November 2020, the Boston University Head Impact Exposure Assessment was launched for data collection 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. Former athletes were divided into those who participated in football (n = 729 [38.9%]) and those who participated in other sports (reference group).ExposuresSelf-reported participation in football, duration and level of football play, age at first exposure.Main Outcomes and MeasuresLogistic regression tested associations between PD status and history of football play, duration of football play, 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.ResultsIn this sample of 1875 men (mean [SD] age, 67.69 [9.84] years) enriched for parkinsonism or PD (n = 1602 [85.4%]), 729 (38.9%) played football (mean [SD] duration, 4.35 [2.91] years). History of playing football was associated with higher odds of having a parkinsonism or PD diagnosis (odds ratio [OR], 1.61; 95% CI, 1.19-2.17). Among the entire sample, longer duration of play was associated with higher odds of having a parkinsonism or PD diagnosis (OR, 1.12; 95% CI, 1.06-1.19). Among football players, longer duration of football play (OR, 1.12; 95% CI, 1.02-1.23) and higher level of play (OR, 2.93; 95% CI, 1.28-6.73) were associated with higher odds of having parkinsonism or PD.Conclusions and RelevanceIn this cross-sectional study of participants enriched for PD, participation in football was associated with higher odds of having a reported parkinsonism or PD diagnosis.

Substantia Nigra Pathology, Contact Sports Play, and Parkinsonism in Chronic Traumatic Encephalopathy

“…Parkinsonism and PD were recently found to be associated with a history of American football play and with longer duration of football play . We did not detect a difference in duration of contact sports participation between participants with and without parkinsonism.…”

“…We did not detect a difference in duration of contact sports participation between participants with and without parkinsonism. This finding may have been due to restriction of the sample to participants with CTE, who had a substantial RHI burden that was higher than the putative threshold for increased risk of parkinsonism ascertained by Bruce et al (approximately 4 years). Individual susceptibility to developing parkinsonism following head injury is heterogeneous and evidently mediated by additional variables, including neuropathologic factors.…”

“…Despite the association of parkinsonism with TBI and, more recently, American football play, the neuropathologic substrates of parkinsonism in CTE are not well known. In this study, in a group of deceased contact sports participants with CTE, parkinsonism was frequent (24.7%).…”

“…Despite the recognized association between head injury and parkinsonism, to our knowledge, a pathophysiologic mechanism for this association has not been defined, and the neuropathologic substrate for parkinsonism following RHI remains unclear. Our group recently reported that years of American football participation were associated with higher odds of parkinsonism and with the development of neocortical LBD . Chronic traumatic encephalopathy, however, is primarily a tauopathy and frequently involves the brainstem; previously, it was found that in individuals with CTE, NFTs within the pontine dorsal or median raphe nuclei were associated with probable rapid eye movement sleep behavior disorder (pRBD), which is typically associated with synucleinopathy .…”

Substantia(l) Impacts of Contact Sport Play and Parkinsonism

“…Prior work from this group found a dose-dependent association of more RHI with primarily neocortical LB, which may explain the absence of an effect of RHI on SN LB, specifically, in this study. These findings come on the heels of recent results from the Fox Insight Study showing that men with prior RHI from American football were at 1.6 times greater odds of having parkinsonism or a Parkinson disease diagnosis compared to men who had played other, noncontact organized sports, even among a sample already enriched for a history of parkinsonism and not selected for known or suspected prior RHI . The Adams et al results shed light on the potential neuropathological underpinnings of the increased risk for parkinsonism in individuals with prior RHI.…”