Doctors Don’t Always Consider Time Factor

When assessing sick patients, many doctors do not take time to think about time, says Dr. William White.

That, he adds, is a mistake.

Most migraine headaches occur between 6 a.m. and noon, the worst period for asthmatics is in the early morning hours before waking, and mornings claim more heart attack victims than any other time of day.

“It used to be thought that heart problems occurred at random,” White said. “They are not random at all.”

White, a cardiologist at the University of Connecticut Health Center, is one of the leading proponents of chronobiology, a field that stresses the importance of the body’s 24-hour clock, or circadian rhythms, in understanding and treating disease.

“It is really an incredible concept,” said Dr. Charles Leach, professor of cardiology at UConn and former director of cardiology at New Britain General Hospital.

“Everything in nature varies through time. Everything contains biological rhythms.”

Menstruating women have no problem accepting that cycles are important to health, but some doctors do.

That’s because generations of medical students have been taught that the body constantly adjusts its functions to maintain an equilibrium, or homeostasis.

Doctors have incorrectly interpreted that concept to mean that time plays little or no role in either the progression of a disease or its effective treatment, White said.

In a 1996 survey of doctors by the American Medical Assn., only 46% knew rheumatoid arthritis sufferers had more pain in the morning and only 26% knew that asthmatics had most attacks between midnight and 6 a.m.

“Modern medicine has become so specialized,” said Michael Smolensky, professor of environmental sciences at the University of Texas in Houston and author of the recently published book “The Body Clock Guide to Better Health.” “No one is feeling the whole elephant.”

Smolensky said the significance of a person’s daily internal cycle has been established for 35 separate diseases.

Some examples cited in his book: Sufferers of osteoarthritis are most likely to experience pain in the afternoon. And diabetics who monitor their blood sugar should be aware that the pancreas produces more insulin in the morning.

Some studies have suggested that the effectiveness of chemotherapy in killing cancer cells varies by time of day, White added.

Cardiovascular disease has a particularly well-documented link to circadian rhythms, said White, who is the editor of a medical book to be published next month on the importance of monitoring blood pressure at different times of day.

For instance, people are three times more likely to die of heart attacks in the six hours before noon than in late evening.

That’s because pulse and blood pressure begin rising rapidly as the body gets ready for the new day.

The clear implication is that hypertension drugs are most needed early in the morning.

One drug company, Searle, part of Pharmacia Corp., now markets a hypertension drug--Covera-HS--that is designed to release medicine during crucial early morning hours.

However, simpler steps such as directing that drugs be taken first thing in the morning are not always followed by medical professionals, Leach said.

“Most hospitals deliver meds to patients at 10 in the morning, four hours after their blood pressures begin to rise,” Leach said.

“You walk into any meeting,” he said, “and doctors are discussing a patient’s blood pressure, and you ask if they considered the time of day. With amazing frequency you find they didn’t.”

Even so, Leach and White said that there has been increased acceptance in the past decade among both doctors and insurers about the importance of taking blood-pressure readings at different times of day.

Leach said that doctors increasingly are applying the common-sense principles of chronobiology, even if some remain suspicious that it’s just a gimmick when they hear the term.

“When I ask them about how they do their jobs,” Leach said, “I tell them they are already practicing chronobiology.”