New research published in JAMA Network Open has shown that physical fitness at a young age, and particularly body mass index (BMI), is important for future cardiovascular health. However, previous studies may have overestimated the effects of fitness on future cardiovascular health after adjustment for genetic and environmental factors.
The study included over one million men with sibling comparisons in Sweden who participated in mandatory military conscription examinations between 1972 and 1995. The men were followed up through 2016 and monitored for the development of cardiovascular disease. The goal of the study was to determine how physical factors in late adolescence, such as BMI, cardiorespiratory fitness, grip strength, and blood pressure, affect the development of future cardiovascular disease and how that risk may be shaped by genetic and environmental factors.
The results showed that BMI, blood pressure, fitness, and grip strength in late adolescence were all associated with cardiovascular disease risk in adulthood, even after controlling for genetic and environmental factors. However, the associations for fitness, blood pressure, and grip strength were weaker than expected after controlling for genetics and environmental factors as determined by the sibling analysis. The connection between BMI and future cardiovascular disease remained strong, suggesting that halting and reversing weight gain early in life should be a priority for preventing cardiovascular disease.
The authors noted that while fitness showed a weaker link than expected, it still had an association with future heart disease and should not be ignored. Adolescence is also an important time for building healthy habits surrounding fitness and diet that may carry into adulthood. However, the most important takeaway from the results was that BMI is a very strong individual risk factor for the development of heart disease that should be addressed as early as possible.
Sources: JAMA Network Open, Science Daily