"The current rates of blood pressure control in the elderly are unacceptably low," said Donald M. Lloyd-Jones, M.D., assistant professor of preventive medicine and assistant professor of medicine, division of cardiology, at Northwestern University Feinberg School of Medicine.
Lloyd-Jones said that among hypertensive individuals in the 1990s, the overall prevalence of blood pressure control (lower than 140 systolic/90 diastolic) was around 34 percent.
Control rates declined with advancing age, with a more dramatic decline in women. Among those 80 and older with hypertension, only 32 percent of men and 24 percent of women had their blood pressure under control.
"The elderly are the fastest-growing segment of the U.S. population, and they have the highest prevalence of hypertension. Yet, clinicians seem to be reluctant to treat older patients aggressively, perhaps because of perceived lower benefits or possible increased risk of side effects," Lloyd-Jones said.
Lloyd-Jones and colleagues from the National Heart, Lung, and Blood Institute's Framingham Heart Study pooled data from almost 14,100 examinations of participants in the study from 1990 through 1999.
The Framingham Heart Study, initiated in 1948 in Framingham, Mass., is the longest-running prospective epidemiological study of heart disease. Researchers are now enrolling the grandchildren of the study's original participants.
The current study included about 2,230 men and 2,960 women. Participants were classified by age - younger than 60, 60 to 79 and 80 and older.
As expected, the prevalence of hypertension increased markedly with advancing age. In the younger-than-60 age group, around 27 percent had high blood pressure; and in the 60-to-79 age group, about 59 percent had high blood pressure. In the group aged 80 and older, over 70 percent had high blood pressure.
The overall prevalence of treatment was around 66 percent. Treatment rates increased substantially from the younger -to-old age group (57 percent to 72 percent), with no further increase in the "old-old," 80-and-over group (73 percent).
However, the number of antihypertensive medications used was similar across all age groups, with two thirds of treated hypertensive patients using only one medication; 25 percent using two medications; and fewer than 10 percent using three medications, Lloyd-Jones said.
Lloyd-Jones noted that the use of thiazide diuretics increased steadily with advancing age, but remained suboptimal.
In the 80-and-older group, only 22 percent of men and 32 percent of women with hypertension were using thiazide diuretics for therapy, despite the fact that thiazides have been shown to be extremely effective in older hypertensive patients.
The investigators also showed that the risks associated with hypertension for development of cardiovascular disease, major coronary events (such as heart attack) and congestive heart failure were substantially higher in the oldest age group compared with those in younger people with high blood pressure.
Lloyd-Jones said there are several major public health implications to be drawn from the study:
- The elderly have the highest prevalence of hypertension and the risks associated with hypertension increase with advancing age.
- Current rates of blood pressure control are unacceptably low for the oldest hypertensives, and particularly women.
- Poor control is due in part to an inadequate number of medications and, perhaps, to poor selection of drug classes.
According the recent Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, treatment principles should be the same for all age groups. Lower initial doses of medications may be needed to avoid side effects in older patients, but standard doses and multiple drugs may be required to reach appropriate blood pressure targets.
"That means physicians should start with low doses, and add more medications as necessary to help patients reach their blood pressure goals," said Lloyd-Jones.
The American Society of Hypertension is the largest U.S. organization devoted exclusively to hypertension and related cardiovascular diseases.
(Editor's note: To reach Dr. Lloyd-Jones during the ASH meeting on May 20 to 23, contact Bob Schwadron in the meeting newsroom at 212-536-4928.)