An inexpensive treatment may prevent disability and cardiovascular disease in millions of older Americans. Yet, many older people don't know that they have a common form of high blood pressure (hypertension), known as isolated systolic hypertension (ISH), or that ISH can be treated effectively. Prevention and treatment of this silent killer are essential because left untreated high blood pressure can damage the kidneys with progression to end-stage kidney disease and also can lead to stroke, heart attack, heart failure, dementia, and blindness.
Blood pressure is typically recorded as two numbers – the systolic pressure over the diastolic pressure. The systolic pressure is the pressure of blood in the vessels when the heart contracts. Diastolic pressure is the pressure of the blood between heartbeats when the heart is at rest. In most people, systolic blood pressure increases steadily with age, while the diastolic blood pressure increases until about age 55 and then declines.
Optimal blood pressure is less than 120/80 mm Hg. High blood pressure is defined as a systolic blood pressure of 140 mm Hg or greater or a diastolic blood pressure of 90 mm Hg or greater. ISH is defined as a systolic blood pressure greater than or equal to 140 mm Hg and a diastolic blood pressure less than 90 mm Hg. In people younger than 55, elevated diastolic blood pressure is a major concern. In older people, elevated systolic blood pressure, even in the absence of elevated diastolic blood pressure, is a concern.
Reducing systolic blood pressure to below 140 mm Hg is the priority in the treatment of ISH. In older people, measurement of systolic – and not diastolic – blood pressure better identifies people with high blood pressure and also those persons who are at increased risk of developing cardiovascular disease. In older people, systolic blood pressure tends to be higher and diastolic blood pressure lower than blood pressure measured in younger individuals.
The first step in preventing the development of ISH is an accurate blood pressure measurement followed by possible changes in lifestyle. Older adults should get their blood pressure checked regularly and monitor the systolic blood pressure number to make sure it is under 140 mm Hg. If the number is not under 140 mm Hg, lifestyle modifications and/or drug treatment may be needed to lower blood pressure.
Medication, such as diuretics, given at the proper dosage, can work to lower high blood pressure. Compelling data from large clinical trials have demonstrated the benefits of treating ISH. For example, the Systolic Hypertension in the Elderly Program (SHEP), a study supported jointly by the National Institute on Aging (NIA) and the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH), showed that patients, aged 60 years and older treated with a thiazide diuretic (chlorthalidone-based regimen) had marked reductions in the rates of heart attack, heart failure, and stroke and also showed some reduction in the risk of depression and dementia. The reduction in heart failure was even greater in older people who previously had a heart attack.
For all Americans, the keys to preventing high blood pressure include: eating a diet rich in fruits, vegetables, and low-fat dairy products; reducing daily intake of cholesterol and saturated and total fats; reducing daily salt intake; maintaining adequate intake of dietary potassium; losing weight, if overweight; limiting alcohol intake, if you drink; increasing aerobic physical activity each day; and stopping cigarette smoking.
Of the estimated 35 million older people living in the U.S., approximately 23 million have ISH, and most of them do not have their blood pressure adequately controlled. According to the American Heart Association, the cost of hypertensive disease in the U.S. in 2001 is estimated at $40.4 billion, which includes the cost of physician and other professional services, hospital and nursing home care, medications, home health care, and lost productivity, and this figure could escalate dramatically as Baby Boomers age. The number of older Americans is expected to reach 70 million by 2030, and the burden of health care could be staggering.
The NIA leads the Federal effort supporting and conducting research on aging, age-related disease, and social and behavioral needs of older people. Part of NIA's research involves ways to prevent frailty and reduce disability with age. For more information about health and aging, visit the NIA website at www.nia.nih.gov. Information about controlling blood pressure and the DASH (Dietary Approaches to Stop Hypertension) eating plan is available from the National High Blood Pressure Education Program, an NHLBI program. The website address is www.nhlbi.nih.gov.