The chance that former professional football players will be diagnosed with hypertension rises in step with the number of concussions they sustain during their careers, new research has revealed.
The results held true even after researchers took into account established risk factors known to drive the risk for high blood pressure, including age, body mass index, race, smoking status, and a diagnosis of diabetes.
Given that cardiovascular illness remains a major risk factor among former athletes and in the general population, the researchers said the results should be an impetus for doctors, former players, and their families to consider a history of prior head injury when screening patients for hypertension — even in the absence of other risk factors for this condition.
The Football Players Health Study at Harvard University also suggests that hypertension could be a further driver of cognitive decline – a condition strongly linked with professional football play in previous studies and believed to stem primarily from repeated head injury – but one which could be a modifiable risk factor.
“If players, families, and physicians are aware of the cardiovascular effects of head injury, we have a better chance of protecting both their cardiovascular health and long-term cognitive health,” said Rachel Grashow, director of epidemiological research initiatives for the Football Players Health Study.
The research — based on a survey of more than 4,000 former National Football League players representing the largest study cohort of former professional football players to date — was conducted as part of the ongoing study at Harvard University, a research program that encompasses a constellation of studies designed to evaluate various aspects of players’ health across their life span.
The researchers collected information from 4,168 former NFL players and analysed known risk factors for hypertension in the general population — diabetes, obesity, age, smoking — as well as players’ number of seasons of play, field position, years since play, and the occurrence of ten common concussion symptoms. These symptoms were used to calculate a concussion symptom score, or CSS.
The analysis showed that as players’ symptom scores rose, so did their likelihood of being diagnosed with hypertension, even after researchers accounted for known hypertension risk factors.
Notably, even using the number of occurrences of just one severe symptom of concussion — loss of consciousness — was enough to accurately predict players’ likelihood of developing hypertension.
Grashow said that while it remains unclear exactly how concussion leads to hypertension, one hypothesis is that repeat concussions could cause a chronic inflammation that prompts blood pressure to rise.
Uncovering the precise mechanism underlying concussion-related hypertension will be the subject for future research, she added.
Professor Aaron Baggish, professor of medicine at the University of Lausanne and senior faculty member at the Football Players Health Study, added that unlike many risk factors for cognitive decline, hypertension is potentially controllable with an array of safe and effective therapies, including routine aerobic exercise, dietary modification, and, in some cases, medication.
“By identifying those at increased risk for hypertension based on their history of head injuries, we could intervene with therapies that not only protect their hearts and blood vessels, but also their brains,” he added.
