History of infertility is associated with increased risk of heart failure
First author Emily Lau, MD, MPH, cardiologist and director of the Menopause, Hormone & Cardiology Clinic at MGH.
Infertility and Heart Failure
Infertility affects about one in five U.S. women and covers a wide range of difficulties conceiving, but its link to heart failure has not been thoroughly studied until recently. In partnership with the Women’s Health Initiative (WHI), designed in the early 1990s and querying a woman’s reproductive history, Lau and colleagues studied postmenopausal women from WHI and check to see if infertility is associated with the development of heart failure.
There are two types of heart failure: heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF).
Ejection fraction is a measurement related to the volume percentage of blood pumped from the left ventricle of the heart during each beat. An ejection fraction less than 50% is generally considered abnormal or decreased.
The team found an association between infertility and overall heart failure, particularly with HFpEF, a form of heart failure that is more common in women regardless of reproductive history. Of the 38,528 postmenopausal women studied, 14% of participants reported a history of infertility. During the 15-year follow-up period, the researchers noted that infertility was associated with 16% of the overall future risk of heart failure. When they examined types of heart failure, they found that infertility was associated with a 27% increased risk of future HFpEF.
Diastolic heart failure in men and women
Over the past decade, diastolic heart failure, or HFpEF (when the heart muscle doesn’t relax well) as opposed to HFrEF (in which the left ventricle doesn’t pump well), has become the most common form of heart failure in both men and women. But it is still more common in women. “It’s a challenging condition because we still don’t fully understand how HFpEF develops and we don’t have good therapies to treat HFpEF,” says Lau.
“I think our finding is particularly interesting because heart failure with preserved ejection fraction is more common in women.” Lau said. “We don’t understand why we see more HFpEF in women. Looking back at women’s early reproductive lives may give us some clues as to why.”
Notably, the team observed that the link persisted regardless of whether an individual was eventually conceived or directly born.
The increased risk was independent of traditional cardiovascular risk factors and other infertility-related conditions.
Association between infertility and cardiovascular metabolic risk factors
“There has been some suggestion in previous studies that women with infertility have more cardiovascular metabolic risk factors.” But the team did not find that cardiometabolic risk factors explained the link between infertility and heart failure in this study, Lau said. They also looked at whether other infertility-related conditions such as thyroid disease, irregular periods, and early menopause could explain the link between infertility and heart failure, but also found no supporting evidence. that hypothesis.
“So it really begs the question: what are the mechanisms driving the link between infertility and heart failure?” Lau said.
Is it shared risk factors, or is infertility on the causal path? She addresses vascular and endothelial dysfunction that may be involved and has a plan to eventually elucidate the underlying mechanism linking infertility and heart failure. In the future, Lau hopes to do a prospective study of women with a history of infertility related to exercise parameters, vascular measures, etc. to solve the mystery.
“We as scientists and doctors are beginning to recognize the importance of a woman’s reproductive history for future heart disease risk. Infertility is one of many risk factors. cardiovascular events, such as hypertension and high blood pressure, but reproductive history should not be considered part of the cardiovascular risk assessment,” Lau said.
Because people don’t tend to develop heart failure until their 60s or older, and infertility mostly occurs in their 20s, 30s, and 40s, many doctors don’t think of the link.
“We can’t change a woman’s history of infertility, but if we know a woman has a history of infertility, we can be more proactive in counseling her about factors that contribute to infertility.” Other modifiable risks include high blood pressure, high cholesterol, smoking, and more.”
Jennifer Ho is the lead author of the paper. This study was supported in part by the National Institutes of Health and the American Heart Association.