Dr. Ali is a Fellow, Geriatrics Division, Saint Louis University School of Medicine, St. Louis, MO. Dr. Ali reports no conflict of interest.
Hypertension (high blood pressure) is a deadly disease that is especially common in the elderly. Over time, abnormally high blood pressure damages the heart and kidneys and increases the risk of stroke, aneurysm and heart attack. Virtually symptomless, hypertension often goes untreated or undertreated. What do doctors know about it and what can be done to treat high blood pressure?
Doctors do know that hypertension becomes more common with age; over 50% of those over 65 have it. In the elderly, hypertension typically takes the form of high systolic blood pressure (SBP), low diastolic blood pressure (DBP) and orthostatic hypotension. Blood pressure readings are expressed by two numbers separated by a slash, e.g., 120/80. The first number is the systolic blood pressure and the second is the diastolic; orthostatic hypotension is an excessive drop in blood pressure when a person stands up; this causes fainting and dizziness.
While all of these conditions are fairly treatable, the reality is that treatment of hypertension in the elderly today leaves much to be desired. Any older person making health care decisions or anyone who is caring for an older person should educate themselves about hypertension, and raise the issue with their doctor or other health care professional.
The Right Way to Take Blood Pressure
Diagnosing hypertension starts with measuring the blood pressure. Taking blood pressure is a simple thing, but it is often done incorrectly. First of all, it is important that the sphygmomanometer, the familiar instrument with a black rubber cuff that is used to take blood pressure, be the right size. Cuffs that are too small for a particular person's arm may give falsely high readings.
Second, someone who is about to have their blood pressure taken should avoid food, exercise, caffeine and smoking one hour before BP measurement.6 Smoking two cigarettes will temporarily raise BP by 10/8 mm Hg for 15 minutes. Drinking a cup of coffee will elevate BP by up to 10/7 mm Hg for from one to two hours. The patient should sit in a warm room for at least five minutes with their arm supported at the level of the heart. Letting the arm hang will elevate SBP by 10 mm Hg because of the effects of gravity.
Smoking two cigarettes will temporarily raise BP by 10/8 mm Hg for 15 minutes. Drinking a cup of coffee will elevate BP by up to 10/7 mm Hg for from one to two hours.
Finally, BP should be checked in both arms; the arm with the higher reading should be used for later readings.
Pseudohypertension is the appearance of high blood pressure in someone who, in fact, does not have it. One common cause of false high blood pressure readings occurs because compression of the brachial artery in the arm, which is common in the elderly, requires using a higher cuff pressure when taking blood pressure. This will produce systolic and diastolic pressure readings that are 10 mm Hg too high or higher.
The Major Risk Factors for Hypertension
Medical researchers have identified factors that increase your risk of having high blood pressure:
- High salt diet — the relation between hypertension, diet and salt intake was demonstrated by a famous study called the DASH low sodium trial. Reduction of salt intake combined with a dietary regimen called DASH (Dietary Approaches to Stop Hypertension) successfully helped many to lower their blood pressure.
- High alcohol intake
- Family history of hypertension
- Obesity — the risk of hypertension for moderately obese men is two times higher than men who are not obese.
- African-American heritage — hypertension is more common and more severe in African-Americans than in otherAmericans.
The United States Preventive Service Task Force (USPSTF) recommends that blood pressure be taken at each medical visit for anyone over 21. This should include assessing risk factors for cardiovascular disease and counseling about life style changes such as increasing physical activity, lowering alcohol consumption and smoking, as well as eating a healthier diet.
It is important that your doctor measure your blood pressure more than once. Studies have shown that as many as 25% of all people — even more among the elderly — who appear to exhibit mild hypertension at the physician's office, may in fact be suffering from medical office examination anxiety, or "white coat hypertension." To avoid falsely labeling such patients as hypertensives, sometimes your doctor may suggest that a nurse check your BP at home or ask you to check your own BP at home.
The Health Effects of Hypertension
Atherosclerosis and coronary artery disease (CAD) are strongly associated with hypertension. Hypertension is the most common risk factor for congestive heart failure (CHF). In hypertensives, the risk of CHF is two times higher than normal in men and three times higher in women. In a study of people aged 40 to 89 who were followed for 20.1 years, 91% of those who developed CHF had a history of hypertension. In the study, those with hypertensive CHF did not live long; only 24% of the men and 31% of the women survived five years.
Stroke is another very serious complication of hypertension. A study called the Systolic Hypertension Trial in Europe (Syst-Eur) showed that aggressive treatment of hypertension reduces the risk of stroke by 42%. According to the Melbourne Risk Factor Study, hypertension is the most important risk factor for intracerebral hemorrhage.
There is no ideal blood pressure that is right for all people at all ages. Your doctor must still decide what goal blood pressure best suits you and how best to achieve it. Life style modification should be tried first.
The Syst-Eur trial also demonstrated a link between dementia and systolic hypertension. These findings indicate that if 1000 people with systolic hypertension were treated for 5 years, 19 cases of dementia might be prevented.
Many trials have confirmed the obvious — that the elderly benefit from effective treatment of hypertension. Successful treatment reduces total mortality by 13%, cardiovascular mortality by 18%, all cardiovascular complications by 26%, stroke by 30% and coronary events by 23%.
Unfortunately, however, these same studies also show that hypertension in the elderly is undertreated. In one study, in the case of elderly people who visited the doctor with hypertension that was documented for at least six months — a clear indication that treatment is needed — doctors started or changed treatment for hypertension only 38% of the time.
"Goal BP" and the Elderly
There is no ideal blood pressure that is right for all people at all ages. Your doctor must still decide what goal blood pressure best suits you and how best to achieve it. Life style modification should be tried first. Salt should be restricted to 2.3 g or 6 g of table salt per day.
Although dietary restrictions can be helpful, they need to be used with care in the elderly because appetite declines with age, and salt restriction can lead to weight loss, which can create further blood pressure complications.
While moderate alcohol intake (one or two drinks per day) is good for the heart and the cardiovascular system generally, alcohol consumption of more than two drinks per day can cause or worsen hypertension.
Is There a Drug of Choice?
Drugs are the primary weapon used today to fight hypertension. Particularly in the elderly, drug therapy for hypertension should be gentle, starting low and going slow, with care to avoid drugs that may cause hypotension (low blood pressure).
The Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)37 suggests that low dose thiazide diuretics have a better cardiovascular protective effect than the newer ACE inhibitors (ACEIs) and calcium channel blockers in patients with risk factors for coronary artery disease, diabetes, previous heart attack, stroke, hyperlipidemia, cigarette smoking or other atherosclerotic cardiovascular disease.
The following drugs may also be prescribed in certain situations:
- Angiotensin converting enzyme inhibitors (ACEIs) are preferable for those with heart failure, chronic renal failure (CRF) and for type 1 diabetics with kidney disease.
- Angiotensin receptor blockers (ARBs) are effective in those who cannot tolerate ACE inhibitors, in severe hypertension with enlarged heart, and in patients who have type 2 diabetes and who are spilling protein into their urine.
- Beta blockers are preferred for those who have had a heart attack because of their positive effect on heart rhythm. They are also beneficial in patients with heart failure.42 Given that many of the elderly are on fixed incomes, it is important to note that beta blockers are relatively inexpensive.
- Calcium channel blockers (CCBs) are often used for those with angina and conditions that make it difficult for patients to tolerate other drugs.
For certain special circumstances, doctors may prescribe a number of other drugs.
While we know much about the treatment of high blood pressure in the elderly, we need to know more. New studies are now on-going which will eventually help doctors better manage hypertension in the elderly. Meanwhile, the best treatment for the hypertensive elderly remains using proper techniques of blood pressure measurement, making the appropriate life style changes, and selecting the right drug or drugs for a particular patient.