High blood pressure has been associated with heart disease for years, but scientists are now beginning to find that pulse pressure - a certain type of high blood pressure - is a more accurate predictor of calcification, atherosclerosis and coronary artery disease.
Blood pressure is the force of blood against the walls of arteries and is usually represented by two numbers. The first number represents systolic pressure, or when the heart contracts. Pressure against the artery walls is at its highest. The second number represents diastolic pressure, or when the heart relaxes.
Pulse pressure is the difference between the systolic and the diastolic readings (the high and low readings) obtained in determining the blood pressure. A person with a normal blood pressure reading of 120/80 has a relatively healthy pulse pressure of 40.
The average pulse pressure is 40; if it falls below 10, it is inadequate to maintain circulation. A person with a normal blood pressure reading of 120/80 has a relatively healthy pulse pressure of 40. When the blood pressure is low, if the pulse pressure is sufficient to maintain circulation, it is considered normal. It is only in a tiny minority of people with low blood pressure, ie, readings below 90/60 mmHg, where there is an underlying cause and treatment may be needed.
Pulse pressure appears to be an indicator of stiffness and inflammation in the blood-vessel walls. The greater the difference between systolic and diastolic numbers, the stiffer and more injured the vessels are thought to be.
A pulse pressure lower than 40 may mean you have poor heart function, while a higher pulse pressure may mean your heart's valves are leaky (valve regurgitation).
The most important cause of elevated pulse pressure is stiffness of the aorta, the largest artery in the body. The stiffness may be due to high blood pressure or fatty deposits on the walls of the arteries (atherosclerosis). Studies have shown that this number should be no more than 60 mm Hg. When greater than 60 mm Hg there is in increased incidence of adverse cardiovascular events especially in the older population.
Under age 50 diastolic is more predictive. At ages 50-59 systolic is most predictive and after 60 the pulse pressure is most important. As one ages there is a gradual shift in the strength of prediction of risk from diastolic to systolic to Pulse Pressure (PP).
Some studies suggest that in people over 45 years old, every 10-mm Hg increase in pulse pressure increases the risk for stroke increases by 11%, cardiovascular disease by 10%, and overall mortality by 16%. (In younger adults the risks are even higher.)
A high resting pulse pressure is harmful and tends to accelerate the normal aging of body organs, particularly the heart, the brain and kidneys. Heightened pulse pressure is also a risk factor for the development of atrial fibrillation.
If the patient suffers from elevated pulse pressure, treatment may include medications that address this factor, such as an angiotensin-converting enzyme inhibitor (ACE inhibitor). The authors of a meta-analysis suggest that this helps to explain the apparent increase in risk sometimes associated with low diastolic pressure, and warn that some medications for high blood pressure may actually increase the pulse pressure and the risk of heart disease. Last, be aware that certain anti-hypertensive drugs and combinations thereof have a better effect on pulse pressure than others. Examples are diuretics and certain calcium channel blockers.
A 2005 study found that 5 mg of folate daily over a three-week period reduced pulse pressure by 4.7 mm of Hg compared with a placebo, and concluded that Folic acid is an effective supplement that targets large artery stiffness and may prevent isolated systolic hypertension.