Researchers followed nearly 6,000 women who had no signs of heart disease when the study launched in 1992. Over the next nine years, those with metabolic syndrome were 57 percent more likely to die than those who didn't have the cluster of risk factors that defines metabolic syndrome. But when researchers controlled the study for women with metabolic syndrome who had higher levels of cardiorespiratory fitness, this elevated risk nearly disappeared - both overall deaths and deaths specific to heart disease fell to rates similar to those of the group of women without metabolic syndrome.
"Through some mechanism, cardiorespiratory fitness may be protective against the adverse effects of metabolic syndrome," says lead researcher Martha Gulati, MD, co-director of the Center for Women's Health at the Bluhm Cardiovascular Institute of Northwestern Memorial Hospital. "Fitness has a protective effect, likely because it reduces other risk factors, lowers heart rate and conditions the heart to respond to stress."
Cardiorespiratory fitness can be determined by measuring the maximal oxygen uptake for a given workload and can be expressed in metabolic equivalents (METs). One MET is defined as the energy it takes to sit quietly. This study defined higher levels of cardiorespiratory fitness as women who are able to perform activities at greater than 8 METs (approximate to being able to run a mile in 12 minutes or faster).
Metabolic syndrome, which increases the risk of cardiovascular disease and diabetes, is defined as having three or more of the following risk factors: a waist circumference of greater than 35 inches in women; high blood pressure; elevated triglycerides; low levels of high-density lipoprotein (HDL); or high fasting glucose levels.
In August of this year, a related study by Dr. Gulati was published in the New England Journal of Medicine which found that otherwise healthy women whose exercise capacity was less than 85 percent the age-predicted value had twice the risk of death compared to women reaching at least 85 percent. "Our findings should provide an added incentive for women, with and without metabolic syndrome, to start working out," Gulati said. "In many aspects, women can take control over their own health and longevity and exercise is one of the keys."
About Northwestern Memorial Hospital
Northwestern Memorial Hospital is one of the country's premier academic medical centers and is the primary teaching hospital of Northwestern University's Feinberg School of Medicine. Northwestern Memorial and its Prentice Women's Hospital and Stone Institute of Psychiatry have 744 beds and more than 1,200 affiliated physicians and 5,000 employees. Providing state-of-the-art care, Northwestern Memorial is recognized for its outstanding clinical and surgical advancements in such areas as cardiothoracic and vascular care, gastroenterology, neurology and neurosurgery, oncology, organ and bone marrow transplantation, and women's health.
Northwestern Memorial received the prestigious 2005 National Quality Health Care Award and is listed in eight specialties in this year's US News & World Report's issue of "America's Best Hospitals." The hospital is also cited as one of the "100 Best Companies for Working Mothers" by Working Mother magazine for the past 5 years and has been chosen by Chicagoans for a decade as their "most preferred hospital" in National Research Corporation's annual survey.
About the Bluhm Cardiovascular Institute
The Bluhm Cardiovascular Institute at Northwestern Memorial Hospital is a world-class heart program offering comprehensive services and state-of-the-art surgical treatments in all areas of cardiovascular care. Recently named by Solucient, an industry-leading healthcare information provider, as the only Chicago hospital on its list of the country's 100 Top Cardiovascular Hospitals, Northwestern Memorial Hospital offers a timely response to referrals and a multidisciplinary approach that joins physicians, nurses and a range of other medical specialists and caregivers from
Cardiology, Cardiac Surgery, Vascular Surgery, Cardiovascular Anesthesiology and Radiology from evaluation to follow-up. Patients benefit from the latest minimally invasive surgical techniques and are offered the opportunity to participate in a range of clinical research trials.
Advanced Cardiovascular Care
Patients referred to the Bluhm Cardiovascular Institute experience a healthcare environment in which the most advanced diagnostic and treatment options are supported by state-of-the-art technology and a commitment to medical excellence through research. Expertise is available in all areas of cardiovascular care, including:
- Valve repair and replacement
- MAZE and atrial fibrillation ablation procedures
- Coronary artery bypass with arterial conduits
- LV and aortic aneurysm repair
- Congestive heart failure surgery
- Ventricular assist devices
- Heart transplantation
- Thoracic and abdominal aortic aneurysm surgery
- Carotid endarterectomy and stents
- Endovascular surgery for aortic aneurysms and limb salvage
- Lower extremity bypass procedures
- Uncommon mesenteric and upper extremity revascularization
- Supraaortic trunk revascularization
- Primary and secondary prevention
- Advanced diagnostic testing including echocardiography, nuclear cardiology, cardiac MRI and computed tomography
- Cardiac electrophysiology, including diagnostic EP procedures, catheter ablation and pacemaker and ICD implantation
- Heart failure management
- Evaluation of heart valve disease
- Acute coronary care
- Diagnostic catheterization and interventional cardiology