Analysis of lipoproteins and body mass index in professional football players

A career in sport does not eliminate risk of cardiovascular disease: A systematic review and meta-analysis of the cardiovascular health of field-based athletes

OBJECTIVES

To determine the prevalence of cardiovascular disease (CVD) risk factors in current field-based athletes.

DESIGN

Meta-analysis.

METHODS

This review was conducted and reported in accordance with PRISMA and pre-registered with PROSPERO. Articles were retrieved via online database search engines, with no date or language restriction. Studies investigating current field-based athletes (>18years) for CVD risk factors according to the European Society of Cardiology and American Heart Association were screened. Full texts were screened using Covidence and Cochrane criteria. Eligible articles were critically appraised using the AXIS tool. Individual study estimates were assessed by random-effect meta-analyses to examine the overall effect.

RESULTS

This study was ascribed a 1b evidence level, according to the Oxford Centre for Evidence-based Medicine. 41 studies were identified, including 5546 athletes from four sports; American football; soccer; rugby and baseball mean ages: 18-28. Despite participation in sport, increased body mass was associated with increased total cholesterol, low-density lipoprotein, triglycerides, hypertension, systolic blood pressure, and decreased high-density lipoprotein. Linemen had increased prevalence of hypertension compared to non-athletes. Conflicting findings on fasting glucose were prevalent. There were inconsistencies in screening and reporting of CVD risk factors. Sport specific anthropometric demands were associated with elevated prevalence of CVD risk factors, most notably: elevated body mass; dyslipidemia; elevated systolic blood pressure and; glucose.

CONCLUSIONS

There are elevated levels of risk for CVD in some athletes, primarily football players. Lifestyle behaviours associated with elite athleticism, particularly football linemen potentially expose players to greater metabolic and CVD risk, which is not completely offset by sport participation.

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.

Prevalence of metabolic syndrome among college football linemen

OBJECTIVE

To determine the prevalence of metabolic syndrome among Canadian amateur football players.

METHODS

University football players from Saskatchewan were invited to participate in this study. Each subject underwent screening for blood pressure using a BpTRU monitor, and serum cholesterol and fasting blood glucose using a Cholestech LDX analyzer. Waist circumference was recorded and body composition was measured by dual-energy x-ray absorptiometry. RESULTS were compared between linemen and non-linemen using independent sample t-tests for continuous data and chi-square for dichotomous variables.

RESULTS

Out of 39 players who consented to participate, 14% of linemen (3/21) and no non-linemen satisfied metabolic syndrome criteria. Compared to non-linemen, linemen had a higher waist circumference (108.0 vs. 82.9 cm; p<0.001), higher total body fat composition (26.4% vs. 11.2%; p<0.001), lower mean high-density lipoprotein cholesterol (0.93, vs. 1.12 mmol/L; p=0.021) and higher fasting blood glucose (5.22 vs. 4.77 mmol/L; p<0.001).

CONCLUSION

Despite their young age and participation in an elite-level athletic program, many collegiate-level football linemen had features of metabolic syndrome. Although our study focused on a single team, we suspect these trends may be consistent across the country.

Review of cardiometabolic risk factors among current professional football and professional baseball players

Data on the development of cardiovascular disease in professional football players are conflicting. Studies have documented a higher prevalence of obesity, lower high-density lipoprotein cholesterol levels, increased left ventricular and left atrial size, and higher prevalence of metabolic syndrome in former professional football linemen compared with nonlinemen. It has been suggested that former National Football League players are at risk for early cardiovascular disease and premature death. A print media report in 2006 indicated an increased prevalence of cardiovascular disease and early mortality in professional football players compared with professional baseball players. However, there has been little scientific evaluation of cardiovascular risk factors in professional baseball players. Our data suggest that there is increased cardiovascular disease risk in football players, but this is limited to heavier linemen. In preliminary studies, baseball players do not appear to demonstrate the same increased risk. However, caution should be used in the interpretation of increased cardiovascular disease risk, as it does not necessarily translate into early increased mortality.