Postmenopausal women with heart disease have three times the risk of developing heart failure if they also have diabetes, researchers report in Circulation: Journal of the American Heart Association.
In addition, diabetic women in the study who also had kidney disease or obesity, or whose diabetes was poorly controlled (fasting blood sugar levels above 300 mg/dL) had a risk of heart failure 6-10 times higher than that of women without diabetes.
Researchers analyzed records from 2,391 participants in the Heart and Estrogen/Progesterone Replacement Study (HERS) to determine risk factors for developing heart failure. Previous studies recognized some significant differences in heart failure between men and women. In men, for example, a heart attack more often precedes heart failure.
“In women, heart failure seems to happen often in the absence of a heart attack,” said Kirsten Bibbins-Domingo, M.D., Ph.D, lead author and an instructor in medicine, epidemiology, and biostatistics at the University of California, San Francisco. “Our goal was to find out what the risk factors were in women.”
Heart failure is a condition in which the heart can’t pump enough blood to the body’s other organs. Physicians diagnose about 550,000 new cases of congestive heart failure annually, and the condition kills nearly 53,000 Americans each year.
In the study, 237 of the women (average age 68.3) developed heart failure during an average of 6.3 years in HERS and its follow-up. The HERS trial tested the effectiveness of hormones in preventing a second heart attack in women who had already suffered one.
The study revealed nine health factors that identify postmenopausal women with coronary artery disease who have an increased risk of developing congestive heart failure. Diabetes was the most powerful predictor of heart failure. Women who had the disease on entering HERS were 3.1 times more likely to develop heart failure than women who did not. The risk from atrial fibrillation (abnormal rapid beats in the heart’s upper chambers) was nearly as great. Women with this abnormal heart rhythm were 2.9 times more likely to develop heart failure than women who did not have the condition.
The seven other factors are, in descending order of significance: two or more previous heart attacks, insufficient kidney function, hypertension, obesity, current smoking, and two heart disorders, left bundle branch block (a block in electrical impulses through the heart) and left ventricular hypertrophy.
“Lifestyle changes and/or medications can modify or prevent several of the nine risk factors,” Bibbins-Domingo said. “Physicians treating women with coronary disease should also focus on the risk factors for heart failure that are preventable or modifiable. These include controlling hypertension particularly, and also controlling blood sugar and obesity.”
Physicians long regarded heart failure as essentially a disease of men. “As with many types of heart disease, we are learning that heart failure is an equal-opportunity disease,” Bibbins-Domingo said. “There is a new realization among clinicians that heart failure, in particular, is also a woman’s disease.”
Among other findings:
- Women with diabetes who had well-controlled blood sugar levels had a relatively low rate of heart failure.
- The danger of developing heart failure increased in women with multiple risk factors. For example, women with none of the 9 risk factors had an annual incidence of only 0.4 percent, while women with three or more risk factors but no diabetes had a 3.4 percent annual incidence of heart failure. The yearly incidence for diabetic women who had three additional risk factors rose to 8.2 percent.
- For women who had diabetes and kidney disease, the annual incidence of heart failure was 13 percent.
- Estrogen/progestin use was not associated with developing heart failure.
- A heart attack increased a woman’s risk of heart failure to 1.4 times that of women who had not had one. Women with two or more heart attacks had a risk 2.5 times greater.
- Women with systolic blood pressure readings greater than 140 millimeters of mercury (mmHg) had a 2.1 times greater risk than those whose systolic pressure ranged from 80 to 120 mmHg.
- Current smokers had 1.9 times the risk of heart failure, “but being a former smoker does not put you at risk—one more reason to stop smoking,” Bibbins-Domingo said.
- Women with a body mass index (a measure of obesity) of more than 35 kg/m2 had a 1.9 times greater risk than those with a BMI of less than 25 kg/m2.
Co-authors are Feng Lin, M.S.; Eric Vittinghoff, Ph.D.; Elizabeth Barrett-Connor, M.D.; Stephen B.Hulley, M.D.; Deborah Grady, M.D.; and Michael Shlipak, M.D.