Weight Gain, Hypertension, and the Emergence of a Maladaptive Cardiovascular Phenotype among US Football Players

Abstract

Importance: Former US football athletes are at increased risk of cardiovascular (CV) morbidity and mortality compared with the general population and other professional athletes. However, responsible maladaptive CV phenotypes have not been fully characterized. Objective: To address the emergence and progression of multiple independent factors associated with CV risk across serial years of collegiate US football participation. Design, Setting, and Participants: Collegiate US football athletes from 2 National Collegiate Athletic Association Division I programs were recruited as freshmen between June 2014 and June 2017 and analyzed at multiple points throughout 3 complete years of collegiate US football participation (until January 2019). Excluded athletes were those who did not complete any season of US football training because of injury, illness, or leaving the team. Factors associated with CV risk assessed clinically, by transthoracic echocardiography, and by vascular applanation tonometry were recorded. Exposures: The exposure of interest was seasonal US football exposure, including training, competition, and the training environment. Main Outcomes and Measures: Primary outcome measures were left ventricular mass index and geometry (cardiac structure), early diastolic myocardial relaxation velocity (E′; diastolic function), and pulse-wave velocity (arterial stiffness). Results: Of 186 individuals recruited as freshmen, 126 athletes were included in analyzed data. Collegiate US football athletes (62 white individuals [49%]; 63 black individuals [50%]; 77 nonlinemen [61%]; 49 linemen [39%]; 126 male individuals [100%]) weighed a mean (SD) of 101.1 (21.0) kg, with a mean systolic blood pressure of 129.1 (11.6) mm Hg at baseline of the freshman season. Adjusting for race, height, and player position, there were significant increases in weight (mean [SE] Δ, 4.74 [0.6] kg; P