Physical fitness and regular exercise reduces a major predictor of cardiovascular disease

May 16 2005

Physical fitness and regular exercise reduces a major predictor of cardiovascular disease in adults with normal blood pressure or mild hypertension. Physical conditioning in the absence of medication is not, however, as advantageous to the more severe hypertensive patient, reported researchers at the American Society of Hypertension Twentieth Annual Scientific Meeting.

"Clinical studies have shown that moderate to intense physical exercise and conditioning such as jogging, aerobics or cycling, done on average at least three hours a week, can have a positive impact on vascular health and a protective effect on arterial stiffness," said Dr. Yvonne Plantinga from the Department of Internal Medicine at University of Pisa, Italy. "Our research showed, however, that habitual physical activity only seems to have a positive impact on arterial stiffness in patients with normal blood pressure or mild hypertension."

"Sedentary lifestyle is among many risk factors, such as aging, hypertension, dyslipidemia and diabetes that elevate the risk of cardiovascular disease significantly," Dr. Plantinga noted. "It has been known for some time that all of these risk factors can lead to a stiffening of the major arteries, which is a good predictor of cardiovascular events."

Arterial stiffness is a measurement of the elasticity of the arteries while the heart pumps blood. In healthy individuals, the central arteries will expand and contract to reduce the overall workload of the heart. However, as the arteries stiffen, pressure on the arterial walls during heartbeats, or systolic pressure, rises while diastolic coronary perfusion, or a measurement of the blood flow in between heartbeats, falls. The net result is an increase of stress on the heart and an increased risk of cardiovascular disease.

Dr. Plantinga and colleagues studied 400 middle-aged patients with normal blood pressure and varying degrees of hypertension and relatively low levels of physical activity. Patients were interviewed on their occupational/work, leisure and sports activities, and then examined for arterial stiffness, measured by pulse-wave analysis through a non-invasive technique called applanation tonometry.

The results of the study confirmed that hypertensive patients had stiffer arteries than those with normal blood pressure, and also found that of the patients with normal or mild hypertension, subjects with low level of physical activity had stiffer arteries than those with higher levels of physical activity. For patients with moderated to severe untreated hypertension, however, a correlation between physical activity and arterial stiffness was not observed.

"Even for patients with moderate to severe hypertension in the absence of pharmacological treatment who got plenty of physical exercise, their arterial stiffness was no better than those with low levels of exercise," said Dr. Plantinga. "Our findings suggest that untreated hypertension seems to level out the beneficial impact of physical activity on cardiovascular risk."

Dr. Plantinga warns that the study results do not undermine the importance of exercise and regular physical activity. The study results suggest that habitual physical activity has a protective effect on arterial stiffness, but the effect is more pronounced in patients with normal blood pressure or mild hypertension. Dr. Plantinga notes that ideal therapy for any patient with high blood pressure should include proper medication, diet and physical activity.

"Our study confirms the importance of keeping blood pressure under control to reduce the risk of cardiovascular disease," said Dr. Plantinga. "If a patient has hypertension, proper pharmacological treatment, diet, and plenty of exercise are essential to achieving this goal."