DALLAS – Biological differences that lead to variations in heart disease between men and women are far more complex than just differences in hormones. To address these differences, UT Southwestern Medical Center researchers say, standards need to be developed for treatment of heart disease in women.
Those conclusions come from an analysis of data from the Dallas Heart Study, a large, multiethnic population study initiated at UT Southwestern in 2000.
In a study published online today in Circulation, UT Southwestern researchers examined sex differences among 30 biological markers in 3,439 individuals. They found significant sex-based differences in lipids, fat hormones, markers of inflammation and artery health, and indicators of muscle damage and kidney function.
“It has long been known that men and women have remarkable differences in their manifestations of heart disease. We used our study to examine the biology that explains these differences,” said Dr. James de Lemos, Professor of Internal Medicine and senior author of the study.
“The large differences we found in the levels of many of the proteins between men and women made us realize that using the same level to diagnose abnormalities in men and women might not be appropriate. It is likely that the normal ranges for these proteins should be different between men and women,” said Dr. de Lemos, who holds the Sweetheart Ball‐Kern Wildenthal, M.D., Ph.D. Distinguished Chair in Cardiology.
Some of the key findings:
- Women tend to have higher levels of fat hormones.
- Women tend to have higher levels of clotting proteins.
- Women tend to have lower levels of proteins that reflect unhealthy arteries.
- Women tend to have higher levels of certain markers of inflammation.
“One of the most striking findings was the influence of body composition and fat distribution on some of the differences we observed,” said Dr. Jeanney Lew, first author of the study and a third-year resident at UT Southwestern. “Differences in where men and women carry fat may have greater influence in women than even levels of sex hormones.”
Clotting factor differences were another area of significant variation between the sexes.
“Women have higher levels of clotting protein circulating in the blood, which may explain, for example, why women are more likely than men to suffer from clotting disorders like deep vein thrombosis and pulmonary embolism. Also, this difference may help explain why women with atrial fibrillation are more likely to suffer stroke,” Dr. de Lemos said.
“At the same time, women have lower levels of vascular disease markers, which may explain in part why women develop atherosclerosis, or plaque buildup in the coronary arteries, later and to a lesser degree than men.”
The findings suggest that sex differences in certain diagnostic measurements, such as levels of the protein troponin that are used to diagnose a heart attack, should be studied further. And, perhaps, the study suggests different threshold levels should be established for men and women.
“So often we just extrapolate exactly what we’ve done in men, who have been studied in much greater depth. It is high time that we begin to understand what drives specific forms of heart disease in women and not automatically apply the same diagnostic and treatment algorithms to the two sexes,” Dr. de Lemos said.
The Dallas Heart Study is an ongoing, multiethnic epidemiologic study funded by the Donald W. Reynolds Foundation. More than 6,000 individuals in Dallas County have participated in the study overall, which has led to more than 200 published papers and key findings about heart disease, cholesterol, and liver disease.
Other UT Southwestern researchers who contributed to this study include Dr. Monika Sanghavi, Assistant Professor of Internal Medicine; Colby Ayers, Faculty Associate in Clinical Sciences; Dr. Darren McGuire, Professor of Internal Medicine; Dr. Ian Neeland, Assistant Professor of Internal Medicine; Dr. Jarett Berry, Associate Professor of Internal Medicine and Clinical Sciences, who is a Dedman Family Scholar in Clinical Care; Dr. Amit Khera, Associate Professor of Internal Medicine, who holds the Dallas Heart Ball Chair in Hypertension and Heart Disease; and Dr. Anand Rohatgi, Associate Professor of Internal Medicine.
The Dallas Heart Study has been supported by grants from the Donald W. Reynolds Foundation and the National Center for Advancing Translational Sciences of the National Institutes of Health (NIH). Biomarker measurements for the study were supported by Roche Diagnostics, Alere, LipoScience, and Siemens Healthcare Diagnostics. Funding support for Dr. Neeland is provided by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases of the NIH and the Dedman Family Endowed Program for Scholars in Clinical Care at UT Southwestern. Dr. Rohatgi is supported by grants of the National Heart, Lung, and Blood Institute of the NIH and by the American Heart Association.
Dr. de Lemos has received grant funding from Roche Diagnostics and Abbott Diagnostics, and consulting income from Roche Diagnostics, diaDexus, Seimens Diagnostics, and Amgen. Disclosures of other research collaborators can be found in the study.
Mars vs. Venus: Sex differences in heart disease
- Heart attacks and angina occur later in life in women.
- Women have fewer plaques in the arteries that serve the heart, and fewer plaque ruptures.
- Of men and women who suffer a heart attack, women are more likely to die.
- Women with atrial fibrillation (a heart rhythm irregularity) are more likely to have a stroke than men.
- Men are more likely to develop congestive heart failure at a young age (under 55), but more women develop heart failure overall.
- Women are more likely than men to develop the kind of heart failure in which the heart still pumps appropriately.
About UT Southwestern Medical Center
UT Southwestern, one of the premier academic medical centers in the nation, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty includes many distinguished members, including six who have been awarded Nobel Prizes since 1985. The faculty of almost 2,800 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians provide medical care in about 80 specialties to more than 100,000 hospitalized patients and oversee approximately 2.2 million outpatient visits a year.