High blood pressure, the "silent killer," too often gets overlooked by people who have conditions that cause them pain or severe distress, a new study finds.

A survey of more than 51,000 people enrolled in a Pennsylvania state prescription drug program found that people with either physical or psychological problems were markedly less likely to take the pills needed to control their blood pressure, according to a report in the June 28 issue of Hypertension.

"It's not so surprising," said study author Dr. Philip Wang. "But what was notable was the consistency with which the presence of other conditions decreased use of antihypertensives [drugs for high blood pressure]."

A wide array of conditions affected use of those drugs, said Wang, an assistant professor of psychiatry, medicine and health-care policy at Harvard Medical School.

For example, someone with both high blood pressure and asthma or another chronic lung disease was 57 percent less likely to take blood pressure medication than someone without such a condition. Use of blood pressure medication was 50 percent lower in people with depression, 41 percent lower for people with gastrointestinal complaints, and 37 percent less likely for people with osteoarthritis.

The blame lies with both patients and doctors, Wang said.

"A patient with several conditions might deal with those that cause discomfort, even though hypertension is probably as important an issue," he said. "And patients may have financial barriers to taking multiple medications. Or maybe they just run out of time."

Doctors know that high blood pressure is a major risk factor for heart attack and stroke, Wang said, so they also play a role in its neglect, though "probably not intentionally." He pointed out that doctors usually have a limited amount of time to spend with individual patients "and if you have to deal with multiple conditions in 15 minutes, hypertension might get short shrift."

The study illustrates "the complexity of the illnesses that older people have these days, and the challenge of dealing with them," said Dr. Daniel W. Jones, dean of the University of Mississippi School of Medicine and a spokesman for the American Heart Association.

The complexity of the American health-care system also plays a role, Jones said. "It's hard to tell what part cost plays in it," he added.

The overall lesson "for patients and their physicians is that blood pressure medications are effective at improving the length and quality of life," Jones said. "Physicians should take care that the problem doesn't fall between the cracks."

A report in the June 28 issue of Circulation highlighted the importance for older people of another silent risk factor -- C-reactive protein.

A study of nearly 4,000 people aged 65 and older found that a high blood level of C-reactive protein is an independent risk factor for heart disease, comparable to high cholesterol levels, the report said. People with the highest levels of C-reactive protein had a 45 percent increase in the risk of developing heart disease over the 10-year course of the study.

"There have been other studies with a shorter-term follow-up, three or four years," said study co-author Dr. Bruce M. Psaty, a professor of pathology and biochemistry at the University of Vermont. "This is the first long-term prospective study in the elderly."

C-reactive protein was almost unknown a decade ago, but a blood test now "is widely available, and is becoming more so over time," Psaty said.

There are several ways to lower levels of the protein, including the use of cholesterol-busting statin drugs, he said. And since "one of the biggest things associated with C-reactive protein is obesity, one of the best ways to control it is to lose weight," Psaty added.