Does the Apolipoprotein [varepsilon]4 Allele Predispose Varsity Athletes to Concussion? A Prospective Cohort Study.
Kristman, Vicki L PhD *+++; Tator, Charles H MD, PhD ++[S]; Kreiger, Nancy MPH, PhD *[P]; Richards, Doug MD [//]**; Mainwaring, Lynda PhD [//]; Jaglal, Susan PhD *++; Tomlinson, George PhD *++++; Comper, Paul PhD [//]**
Clinical Journal of Sport Medicine.
18(4):322-328, July 2008.
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Objective: To determine the association between the apolipoprotein [varepsilon]4 allele and concussion. We hypothesized that apolipoprotein [varepsilon]4 carriers may be more likely to sustain a concussion.
Design: Prospective cohort study.
Setting: University of Toronto varsity athletics.
Participants: Included 318 of 822 collegiate student athletes who participated in University of Toronto varsity sports from September 2002 to April 2006.
Assessment of Risk Factors: The presence of apolipoprotein [varepsilon]4 was described dichotomously after genotyping blood samples collected from participants.
Main Outcome Measurements: 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 [varepsilon]4 and first concussion.
Results: The unadjusted hazard ratio for concussion in the apolipoprotein [varepsilon]4 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.
Conclusions: There is no important association between carrying the apolipoprotein [varepsilon]4 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.
(C) 2008 Lippincott Williams & Wilkins, Inc.