To determine the association between the apolipoprotein ε4 allele and concussion. We hypothesized that apolipoprotein ε4 carriers may be more likely to sustain a concussion.
Prospective cohort study.
University of Toronto varsity athletics.
Included 318 of 822 collegiate student athletes who participated in University of Toronto varsity sports from September 2002 to April 2006.
The presence of apolipoprotein ε4 was described dichotomously after genotyping blood samples collected from participants.
Concussions were identified by sport-medicine professionals present on the sidelines using on-field assessment forms. All concussion diagnoses were verified by a sports medicine physician. Survival analysis was used to determine the association between apolipoprotein ε4 and first concussion.
The unadjusted hazard ratio for concussion in the apolipoprotein ε4 carriers was 1.18 (95% CI: 0.52, 2.69) compared to noncarriers. Adjustment for sex, weight, height, and team type resulted in a hazard ratio of 1.06 (95% CI: 0.41, 2.72), indicating little effect from confounding factors.
There is no important association between carrying the apolipoprotein ε4 allele and sustaining a concussion. At this time, we do not recommend preseason genetic testing for varsity athletes as a mechanism for targeting prevention strategies.
From the *Department of Public Health Sciences, University of Toronto; †Centre of Research Expertise in Improved Disability Outcomes (CREIDO), University Health Network, Toronto Western Hospital; ‡Toronto Western Research Institute, University Health Network; §Division of Neurosurgery, Department of Surgery, University of Toronto; ¶Cancer Care Ontario; ∥Faculty of Physical Education and Health, University of Toronto; **Toronto Rehabilitation Institute; ††Department of Physical Therapy, University of Toronto; ‡‡Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada.
Submitted for publication December 21, 2007; accepted April 30, 2008.
Supported by the Ontario Neurotrauma Foundation, Ontario Neurotrauma Foundation (V.K.), and a Doctoral Training Award from the Canadian Institutes of Health Research in partnership with the Canadian Institute for the Relief of Pain and Disability (formerly the Physical Medicine Research Foundation) Woodbridge Grants and Awards Program (V.K.).
Presented in part at the National Neurotrauma Symposium, Kansas City, Missouri, 30 July 2007; the First Annual Meeting of the Canadian Association for Neuroscience, Toronto, Ontario, 23 May 2007; the Second Annual Canadian Genetic Epidemiology & Statistical Genetics Meeting, Toronto, Ontario, 16 April 2007; the Brain Injury of the Americas Conference, Miami, Florida, 15 Sept 2006; and the Eighth World Conference on Injury Prevention and Safety Promotion, Durban, South Africa, 4 April 2006.
Reprints: Dr. Vicki L. Kristman, PhD, Toronto Western Hospital, Fell Pavilion 4-132, 399 Bathurst Street, Toronto, Ontario, Canada M5T 2S8 (e-mail: firstname.lastname@example.org).