A new study, published by the Stanford University by JAMA Internal Medicine has revealed that body mass index (BMI) and aerobic capacity in adolescents is linked to increased risk of high blood pressure.
Aerobic capacity and muscular strength is used to examine the impact of physical fitness and is measured in watts and muscular strength is measured in newtons. The study population consisted of 1.5 million 18 year old men, observed up to maximum age of 62. Among the 1.5 million men, 93,035 (6 percent) were subsequently diagnosed with hypertension with an average follow-up of nearly 26 years. The median age of participants at hypertension diagnosis was nearly 50.
The research findings indicate that high BMI and low aerobic capacity (but not muscular strength) is associated, with an increased risk of high blood pressure, independent of family history and socioeconomic factors. Low aerobic capacity is associated with an increased risk of hypertension even among men with normal BMI. The combination of high BMI (overweight or obese vs. normal) and low aerobic capacity was associated, with the highest risk of hypertension. A combination of low aerobic capacity and high BMI was associated with a risk of hypertension that was 3.5 times higher relative to the group of men with high aerobic capacity and normal BMI.
“If confirmed, these findings suggest that interventions to prevent hypertension should begin early in life and include not only weight control but also aerobic fitness, even among those with a normal BMI,” the researchers specify.
A prior study published in the Journal of the American College of Cardiology has demonstrated that elevated blood pressure, at an early stage is a predictor for heart failure, after the age of 50. The research participants consisted of 2,479 men and women, between ages 18 and 30. Their blood pressure was assessed seven times, over a period of 25 years. The estimated “cumulative blood pressure exposure” was evaluated by multiplying their systolic blood pressure (when the heart is contracting) and diastolic blood pressure (between beats) at each of the seven time points by the year in which they were measured. Three percent of people younger than age 18 years have high blood pressure,
Normal blood pressure should be less than 120 millimeters of Mercury systolic, over 80 nn HG diastolic. High blood pressure is diagnosed, at 140/90 mmHg or more.
“Our findings provide further support for the importance of good risk factor control early in life,” said senior author Dr. Joao A.C. Lima of the cardiology division at Johns Hopkins University School of Medicine in Baltimore, Maryland.
“Many participants were not hypertensive at the beginning of the study; however, chronic exposure to higher blood pressure, even within what is considered the normal range, is associated with cardiac dysfunction 25 years later,” he said in a news release.
The research findings specified that by age 50, 135 of the participants had left ventricle dysfunction, in which the heart was markedly weaker at pumping blood to the body, during beats or between beats. Those who had higher blood pressure readings in their younger years, between 120/80 to 139/89 before age 30, were more likely to have left ventricular dysfunction between heartbeats than those with lower blood pressure.
“In children (high blood pressure) should elicit a careful hunt for secondary causes – especially kidney disease, endocrine and vascular problems,” Marwick said.
“Weight management, control of salt intake and physical activity are important lifestyle interventions that are important across the population,” to decrease the risk of elevated blood pressure, he said.
1.Casey Crump, Jan Sundquist, Marilyn A. Winkleby, Kristina Sundquist. Interactive Effects of Physical Fitness and Body Mass Index on the Risk of Hypertension. JAMA Internal Medicine, 2016; 1 DOI: 10.1001/jamainternmed.2015.7444