Predicting heart disease risk and aging processes: the understudied placenta
“The placenta is interesting – it has a short life span of nine months and ages in that time like any other part of the body. It’s a great model for studying aging,” says Dr. Tony Parks, a Perinatal Pathologist who has studied the placenta for decades. His research, in collaboration with colleagues at the University of Pittsburgh, has recently been highlighted by the American Heart association as one of the top ten “advances in cardiovascular disease research for 2022”.
Gestational hypertension, or high blood pressure during pregnancy, is found in around 45 of 1,000 births in Canada and approximately 12 in 1,000 suffer from preeclampsia, a more extreme form which causes damage to other organs such as the kidneys or liver. It is now known that women who suffer from preeclampsia are also at a two – four-fold increased risk of developing early cardiovascular disease. Intriguingly, their placentas often develop vascular damage reminiscent of that seen in cardiovascular disease. While the similarity of these various placental vascular lesions (collectively termed maternal vascular malperfusion) to cardiovascular disease has long been noted, no one had attempted to study their significance for the mother’s health.
Dr. Parks is a Professor in the Department of Laboratory Medicine and Pathobiology in the Temerty Faculty of Medicine, and Staff Pathologist at Mount Sinai Hospital. With his collaborator, Dr. Janet Catov at the University of Pittsburgh, they secured funding from the American Heart Association to probe cardiovascular outcomes in women.
The group has been studying a group of 500 women 8 - 10 years after delivery to investigate the association of placental pathology to early cardiovascular disease. The women were selected based on having had a histological review of their placentas previously by Dr. Parks for clinical indications. Roughly ten years after delivery, enough time to see changes, but early enough to avoid age-related onset of cardiovascular disease, the women in this group were brought back for a battery of tests, including blood pressure readings, metabolic profiles, and assessments of the visible microvessels on the underside of the tongue.
The investigators discovered that women whose placentas showed the vascular damage of maternal vascular malperfusion had an increased risk to develop increased diastolic blood pressure, elevated total and LDL cholesterol and vascular changes indicative of a high-risk profile for cardiovascular disease. A follow up pilot study of cognitive function and published in another journal found that women with a history of preeclampsia and maternal vascular malperfusion had slower information processing speeds and decreased cerebrovascular reactivity.
“Not all women with preeclampsia will necessarily develop cardiovascular issues later in life. There appears to be a subset of women and it’s those who show pathological indicators in the placenta,” explains Parks.
Less than half of all placentas are examined after birth, so placental pathology would not be practical as a screening test. These studies are better considered as helping to guide future studies toward finding a biomarker for women at increased risk for cardiovascular disease and potentially new treatment modalities.
On this research being recognised by the American Heart Association, Parks said “Our research is a little bit off the beaten path, so I was completely shocked and it’s very gratifying. Although how we’re looking at this issue of aging and cardiovascular health maybe somewhat unusual, it is very significant.”
Find out more about this research
Hear Dr. Tony Parks present at the upcoming conference: Making Sense of Senescence: Aging Through a Microscopic and Macroscopic Lens on Saturday, January 14, 2023 in the University of Toronto Medical Sciences Building, Toronto.