A longitudinal study examining the effects of a season of American football on lipids and lipoproteins

BACKGROUND: Dyslipidemia is one factor cited for increased risk of cardiovascular disease (CVD) in American football players. However, American football players undergo physical conditioning which is known to influence lipids. This study examined if the physical activity of an American football season is associated with changes in lipids and if a relationship exists between lipids and body composition. METHODS: Fourteen division I freshmen American football players had blood drawn prior to summer training (T1), end of competition (T2), and end of spring training (T3). Samples were analyzed for total cholesterol (TCHL), HDL-C, LDL-C, and triglycerides (TG). Body composition was assessed via dual-x-ray absorptiometry. National Cholesterol Education Program (NCEP) lipid categorization was used to characterize participants. Pearson correlations were computed to determine relationships. RESULTS: Body mass increased T2 (p=0.008) as a result of increase in fat mass (p=0.005) and remained high despite a decrease T3. Lean mass did not differ significantly at any time. No significant time effects were observed for lipids measured. The number of participants presenting with risk factors attributed to dyslipidemia varied. By T3, no participant was categorized as "low" for HDL-C. TCHL was moderately correlated (r=0.60) with fat mass at T1; whereas a moderate correlation (r=-0.57) was observed between BMI and HDL-C at T2. TG was strongly correlated with fat mass at each time point (T1, r=0.83; T2, r=0.94; T3, r=0.70). CONCLUSION: The physical activity associated with a season of football results in little change in blood lipids and CVD risk. Further, TG are strongly related to fat mass. Future research should focus on examining the cause of dyslipidemia in American football players.