Heart disease is the leading cause of death for both men and women. Be that as it may, an enormous number of unexpected losses could be prevented by taking appropriate preventive measures.
Among these measures, physical activity is often prescribed as it has multiple benefits. Also, international guidelines emphasize the need to be active to avoid cardiovascular mortality.
But physical activity is a broad concept, and few scientific studies have looked into the differences between various types of exercise may have. These are the findings of a new study led by Inserm researcher Jean-Philippe Empana (U970 PARCC, Inserm/Université de Paris) in collaboration with Australian researchers.
Jean-Philippe Empana, the lead author of the study, said, “Our idea was to look at whether all types of physical activity are beneficial, or whether under some circumstances physical activity can be harmful. We wanted in particular to explore the consequences of physical activity at work, especially strenuous physical activity such as routinely carrying heavy loads, which could have a negative impact.”
For the study, scientists gathered the data from participants in the Paris Prospective Study III, which monitored the health status of over 10,000 volunteers, aged 50 to 75 years old, and recruited during a health check-up at the Paris Health Clinic (Paris Preclinical Investigations, IPC).
During the study, participants were asked to fill out a questionnaire about the frequency, duration, and intensity of their physical activity in three different contexts: physical activity through sport, physical activity at work (for instance conveying overwhelming loads), and physical activity in their leisure time, (for example, gardening).
Scientists then accessed cardiovascular health based on the health of their arteries using cutting-edge ultrasound imaging of the carotid artery, called echo tracking. The method can also be used to measure baroreflex sensitivity, a mechanism of automatic adaptation to sudden changes in blood pressure. When this system is impaired, this can lead to significant health problems and a higher risk of cardiac arrest.
Scientists then distinguished between two components of the baroreflex: mechanical baroreflex, assessed through the measurement of arterial stiffness, and neural baroreflex, evaluated through the measurement of nerve impulses sent by the receptors on the walls of the artery, in response to distension of the vessel.
Abnormalities in the mechanical component tend to be related to aging-related cardiovascular diseases, while abnormalities in the neural part tend to be linked to heart rhythm disorders that can lead to a cardiac arrest.
The study suggests that high-intensity sporting physical activity is associated with better neural baroreflex. On the other hand, physical activity at work (such as routinely carrying heavy loads) appears to be more strongly associated with an abnormal neural baroreflex and higher arterial stiffness. Thus, such activity could become harmful for cardiovascular health, and in particular, may be related to heart rhythm disorders.
Empana said, “Our findings represent a valuable avenue of research for improving our understanding of the associations between physical activity and cardiovascular disease. They do not suggest that movement at work is harmful to health. Instead, they suggest that continuous, strenuous activity (such as lifting heavy loads) at work maybe.”
“We will attempt to replicate these results in other populations and explore in greater detail the interactions between physical activity and health. This study has major public health implications for physical activity at work. We now want to expand our analysis to further explore the interactions between physical activity and the health status of people in the workplace.”
The results have been published in Hypertension.