And now the other side of the room

Last week, I explained how the results of a treadmill test may be the best predictor of lifespan, better even than smoking habits or the presence of cardiovascular disease or diabetes. In that study, men with the lowest exercise capacity were about four times more likely to die during follow up than those at the highest fitness levels.

Many of you wrote to thank me for that reminder on the importance of exercise. And many women wrote to also ask how, or if, those results applied to us.

Fortunately, I just came across some new research that addresses that question – and reinforces the value of the treadmill test for everyone. In two separate studies, researchers at Johns Hopkins University showed that the treadmill test is an accurate predictor for both men and women – and that the test may help reveal problems in patients who don’t exhibit other traditional warning signs.
Treadmill test reveals hidden heart disease in both sexes

In these studies, the researchers examined data from the national Lipid Research Clinics Prevalence Study, which gathered data at Hopkins and nine other medical centers across the U.S. between 1972 and 1976. The 3,775 men and 2,001 women who participated underwent treadmill tests at baseline, and then were tracked for an average of 20 years with annual questionnaires, phone calls and/or personal visits. (Both of the studies were presented last week at the annual meeting of the American College of Cardiology in Atlanta.)

The data showed that women with abnormal or inconclusive results on the treadmill test were more than TWICE as likely to die from cardiovascular disease during follow up compared to women with normal treadmill test results. They were also slightly more likely to die from other causes as well, though the connection was not as significant.

The same held true for men; men with abnormal or inconclusive results were twice as likely to die from heart disease, and about one and a half times more likely to die from any cause.

The researchers also found that the treadmill tests revealed blood flow problems even in patients that hadn’t shown any of the standard symptoms of heart disease, like angina (chest pain), previous heart attacks, or exercise-related cramping.
Methods vary, but predictive strength remains strong

The treadmill test used in the Hopkins studies was slightly different than in the study I wrote about last week. That study, published in the New England Journal of Medicine, measured exercise capacity in metabolic equivalents (METs); one MET is roughly equal to the amount of oxygen required by the average adult while sitting quietly, and MET levels increase along with exertion. This is assessed by having the patient breathe through a mask while on the treadmill to measure oxygen and carbon dioxide flow.

In this research, the treadmill tests were more traditional, measuring heart rate, blood pressure, and the electrical function of the heart through sensors. The Hopkins studies did not assess METs or maximum exercise capacity.

But both sets of data clearly support the predictive value of treadmill tests in assessing heart health, no matter what the exact protocol. And, they show that this test is reliable for both women and men.

Even more importantly, they suggest that a treadmill test may be a valuable tool in the early detection of heart disease for those at increased risk. In a John Hopkins press release discussing the studies, the lead researcher, Samia Mora M.D. said, “The current guidelines say that it’s not necessary to do routine treadmill exercise tests on people without symptoms, but our studies suggest that for those with high cholesterol or other diseases, it might be warranted.”

If you have any of the common markers for heart disease, but have not yet been diagnosed, ask your doctor about taking a treadmill test. It’s a proven way to assess your REAL risk, so you can start reversing it now.

Source:
“Treadmill exercise tests point out hidden heart disease”
http://www.hopkinsmedicine.org/press/2002/MARCH/020319.htm

Copyright 1997-2002 by Institute of Health Sciences, L.L.C.