A recent study published in JAMA Internal Medicine looked at the effects of both weight and fitness on blood pressure. As authors explain, it’s well known that inactivity and overweight increase risk for high blood pressure—a major risk factor for heart disease and stroke. However, less is known about the combined effects of adolescent weight and fitness on blood pressure as an adult.
To learn more, researchers analyzed health data from more than 1.5 million men enlisting in the Swedish military between 1969 and 1997. Most men were 18 years old upon enrollment. All underwent physical exams to assess fitness, muscle strength and body fat. Participants were then followed for as long as 44 years, tracking key health outcomes like high blood pressure.
During the follow-up period, 6% of men were diagnosed with high blood pressure. Researchers found that high body mass index or BMI (measure of height and weight) and low fitness level at the start of the study were independently associated with increased risk for hypertension later in life. After taking into account factors like age, family history and income, overweight or obese men had 2.5 times greater risk for hypertension than men who were normal weight. Similarly, men with the lowest fitness level at the start of the study were 1.5 times more likely to develop high blood pressure than men with the highest fitness level.
But perhaps most concerning, researchers found that being overweight and unfit was an even more dangerous combination for men as they got older. Men with both a high body mass index and low fitness level at age 18 were more than three and a half times more likely to develop high blood pressure as an adult than fit men with a healthy weight.
Interestingly, researchers also noted that muscular strength was not significantly associated with hypertension risk in this study.
Based on findings, authors conclude that having a low fitness level and being overweight or obese in adolescence significantly increases risk for hypertension as an adult. Together, these common risk factors increase risk for high blood pressure even further.
However, since this study included only Swedish men, authors encourage future research on the issue. If confirmed in a more diverse population, findings suggest that interventions to promote both weight control and fitness early in life could help prevent hypertension as an adult.