Fitness Now for Good Blood Pressure Later

High blood pressure risk was lowest in patients who were the most fit

(RxWiki News) Being fit may make you look and feel great — and it could ward off future health risks like high blood pressure.

A new study found that greater fitness lowered the risk of developing hypertension in the future. High fitness levels also lowered hypertension risk in patients who were already at a higher risk for heart disease.

Sarah Samaan, MD, FACC, a physician partner at The Baylor Heart Hospital in Plano, TX, told dailyRx News that exercise is an excellent way to lower stress and keep the heart healthy.

"Exercise will help you cope more effectively with stress, by tuning up the parasympathetic nervous system," Dr. Samaan said. "This is the 'mellowing out' side of your nervous system, designed to help calm the heart rate and blood pressure, as opposed to the 'fight or flight' sympathetic nervous system. People who exercise are also more likely to make healthier choices."

Stephen P. Juraschek, MD, PhD, of the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease in Baltimore, MD, led this study.

This study followed a total of 57,284 patients, who took a doctor-referred treadmill stress test. Among these patients, 35,175 had a history of hypertension. The other 22,109 did not.

The treadmill stress test is when patients go to a lab to have their heart rate and blood pressure recorded while walking or running on a treadmill. Sticky electrodes, which detect the electrical activity of the heart and are connected to the stress test machine, are also attached to the patient’s chest, shoulders and hips.

Before the treadmill test, Dr. Juraschek and team took the patients' resting blood pressures. During the test, physical fitness was measured in metabolic equivalents (METs) to see how many energy was burned.

METs estimate how much oxygen your body uses per body weight kilogram per minute. Since 1 MET is already used when you’re at a resting state, anything more than 1 MET is equal to energy burned when the body moves. The patients were divided into four groups: those who reached fewer than 6 METs, 6 to 9 METs, 10 to 11 METs, and 12 or more METs.

As the study went on, from 1991 to 2009, these researchers focused on incident hypertension, which was defined as a patient without a history of hypertension developing it during the study. To count as an incident hypertension case, the patient had to be diagnosed with hypertension three separate times in a row. This was to make sure that the blood pressure readings were accurate and precise.

During the follow-up period, 8,053 (36 percent) patients without hypertension history developed hypertension.

The number of METs patients reached during the treadmill stress test appeared to be tied to their risk of developing high blood pressure. For instance, 49 percent those who reached fewer than 6 METs developed high blood pressure — versus 21 percent of those who reached 12 or more METs.

In other words, patients who burned off 12 or more METs' worth of energy when exercising had a 20 percent lower risk of developing hypertension than those who reached 6 or fewer METs.

Dr. Juraschek and team saw that this held true for men and women of all ages, races, weights (including obese patients or those with diabetes) and resting blood pressures.

The resting blood pressure for the treadmill test was based on only a single measurement, Dr. Juraschek and team noted. So data showing changes in fitness level over time was not available.

These researchers also noted that patients joined the study based on referral for a stress test, which means their risk of heart disease was likely greater than that of the general population.

This study was published Dec. 17 in the Journal of the American Heart Association.

The authors disclosed no funding sources or conflicts of interest.

Review Date: 
December 16, 2014