Exercise Decreases Salt’s Effect on Blood Pressure

Salt intake less important to reducing hypertension in athletes

(RxWiki News) Evidence mounts from all corners to continue a regular exercise program and low-salt diet.   A new study supports this recommendation and shows an inverse relationship in the amount of exercise one gets and the effect salt intake has on their blood pressure.

Casey M. Rebholz, M.P.H. a student at Tulane School of Medicine and lead author of the study, observed restricting sodium in more sedentary people is particularly important in lowering their blood pressure.

While still recommending a low-salt diet, Rebholz observed that physically active people were less susceptible to a rise in blood pressure in response to salt-intake in their diet.

dailyRx Insight: Increase your exercise and eat less sodium to reduce your blood pressure.

Researchers divided the study’s participants into four groups: a very active group, a moderately active group, a less active group and a sedentary group. Then, they compared study participant’s blood pressure on two one-week diets. One diet was low in sodium and the other was high in sodium.

The average systolic blood pressure going from a low to a high sodium diet were: 5.27 mm Hg in the sedentary group, 5.07 mm Hg in the less active group, 4.93 mm Hg in the moderately active group, and 3.88 mm Hg in the very active group.

After gathering this data, which was adjusted in all groups to take into account gender and age, the risk of being affected by a high salt diet was 10 percent lower in the less active group, 17 percent lower in the moderately active group, and 38 percent lower in the most active group compared to the sedentary group.

The 1,906 participants in the study were Han Chinese adults with an average age of 38. They are participating in the Genetic Epidemiology Network of Salt Sensitivity (GenSalt), a project to reveal genetic and environmental factors leading to salt sensitivity. All of the participants in the study have a family history of pre-hypertension or stage-1 hypertension.

It is estimated that close to 30% of the United States population has high blood pressure (hypertension), or about 90 million people. Blood pressure is measured as the force the pumping blood exerts on the walls of the arteries in the body. When this pressure is higher than normal (120/80 mmHg), patients are at risk for heart attack, stroke, congestive heart failure, kidney failure, and aneurysms in the arteries and brain. Even moderate high blood pressure can lead to a shortened life expectancy. Most high blood pressure is asymptomatic, and is discovered during a routine checkup. As blood pressure reaches dangerously high levels, some people may experience symptoms such as headache, ringing in the ears, visual changes, and irregular heartbeat. These symptoms are a medical emergency. At particularly high risk for high blood pressure are African Americans, people who are obese, smokers, diabetics, having high salt intake, and having a family history. Alcohol abuse and cocaine use can also cause hypertension. Diagnosis is made by measuring blood pressure over several doctors visits, and is treated by lifestyle modification first, such as smoking cessation, weight loss, dietary changes, and exercise. There are hundreds of different medications to treat hypertension, such as beta-blockers (Lopressor, Inderal), diuretics (Diamox, HydroDiuril), Calcium channel blockers (Norvasc, Procardia), and ACE inhibitors (Lotensin, Vasotec, Capoten).

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Review Date: 
March 30, 2011