Scientists show that high leptin levels in preeclampsia trigger a cardiovascular cascade that puts mother and child at risk | Health

In preeclampsia, which puts both mother and baby at risk, researchers have found that an increase in the hormone leptin in mid-pregnancy, which most of us associate with appetite suppression, causes appetite disturbances in the blood vessels and limits the growth of the baby. The research results were published in the journal “Hypertension”.

Before a baby is born, critical problems in the nutrition and oxygen supply chain can lead to premature birth or even death and increase the risk of cardiovascular disease for both child and mother throughout life. life long. It is known that about 20 weeks into a pregnancy, women with preeclampsia experience increased production of leptin by the placenta, but the consequences are unknown.

“It’s emerging as a marker for preeclampsia,” said Dr. Jessica Faulkner, a vascular physiologist in the Department of Physiology at the Medical College of Georgia and corresponding author of the study in the journal Hypertension. Leptin, produced primarily by fat cells, is also produced by the temporary organ, the placenta, which helps a mother supply her developing baby with nutrients and oxygen, Faulkner said.

Leptin levels rise steadily during a healthy pregnancy, but it’s unclear what leptin even normally does in this scenario. There is evidence that it is a natural nutrient scavenger in reproduction or possibly a way to allow new blood vessels to grow and/or stimulate growth hormone for habitual development . “But in preeclamptic patients, leptin levels rise more than they should,” Faulkner said.

The new impact research shows for the first time that increased leptin leads to endothelial dysfunction in which blood vessels constrict, their ability to relax is impaired and the baby’s growth is restricted. When scientists inhibited the precursor to powerful natural blood vessel dilator nitric oxide, like what happens in hypertension, it roughly mimics the effect of leptin rising in mid-gestation.

To make matters worse, scientists also have evidence that leptin plays a role in increasing levels of blood vessel constrictor endothelin. Conversely, when they removed the aldosterone receptor, in this case the mineralocorticoid receptors on the surface of cells that line blood vessels. , endothelial dysfunction did not occur, said Dr. Eric Belin de Chantemele, a physiologist at the MCG’s Center for Vascular Biology and lead author of the paper.

“We think what’s happening in preeclamptic patients is that the placenta isn’t formed properly,” Faulkner says. “In mid-gestation, fetal growth doesn’t occur as it should. I think the placenta compensates by increasing leptin production,” potentially in an effort to help stimulate more normal growth. But the results seem to be quite the opposite. “It can harm the baby’s development and increase the risk of long-term health problems for the baby and the mother,” she said.

Although leptin has been associated with preeclampsia, this is the first study to show that when leptin rises, it induces the unhealthy clinical features of preeclampsia, Chantemele’s Belin said. When they infused pregnant mice with leptin to mimic the surge that occurs in preeclampsia, they found an unhealthy chain reaction with the adrenal gland making more steroid hormone aldosterone, which could increase production of endothelin 1, also by the placenta.

Their previous work has shown that outside of pregnancy, leptin infusion leads to endothelial dysfunction. Belin’s lab at Chantemele pioneered work showing that fat-derived leptin directly induces the adrenal glands to produce more aldosterone which activates mineralocorticoid receptors found throughout the body, including blood vessels in women, which is important for blood pressure levels. High aldosterone levels are a hallmark of obesity and a major cause of metabolic and cardiovascular problems. This work caused them to hypothesize that the leptin infusion that occurs during mid-gestation in preeclampsia had a similar impact that suppression of mineralocorticoid receptors lining blood vessels might resolve. They connected similar physiological points in young women, in whom obesity often robs the early years of the protection against cardiovascular disease that being a woman typically provides until menopause.

Those same gamblers are likely factors that increase the mother’s risk of lifelong cardiovascular problems, Faulkner says. “It means the system is deregulated and that’s basically when you develop the disease,” she said.

Their goals include better defining the pathways of increased blood pressure and other blood vessel dysfunction, pathways that can be targeted during pregnancy to avoid potentially devastating outcomes for mother and baby, which Faulkner calls of “two-shot condition”. Their findings to date indicate that effective therapies to better protect mother and baby could be existing drugs like eplerenone, a blood pressure drug that binds to the mineralocorticoid receptor, effectively reducing the effect of higher levels of aldosterone, according to scientists.

The problems likely start with the placenta and potentially inadequate blood flow to the temporary organ early in its development and the subsequent failure of development of the large blood vessels that become the passageway for nutrients and oxygen from mother to baby. . It is known that in preeclampsia there are problems like decreased secretion of placental growth factors. The bottom line seems to be that mid-gestation the placenta can no longer properly support the baby, which may explain why it secretes leptin, perhaps in an effort to stimulate its own growth and normal fetal development. , but actually it helps the cardiovascular system. and deadly consequences, the scientists report, including increased blood pressure in the mother.

“Rates of preeclampsia, unfortunately, are increasing,” Faulkner says, both in the number of pregnant women affected and in the severity of it. According to an analysis of data from the Centers for Disease Control and Prevention published in January of this year in the Journal of the American Heart Association, rates of hypertension that occurs during pregnancy, including preeclampsia and gestational hypertension, have almost doubled in rural and urban areas of this country from 2007 to 2019 and has been accelerating since 2014. Gestational hypertension is an increase in a pregnant woman’s blood during mid-gestation but without associated signs of protein in the urine , signs of renal distress or markers of placental dysfunction, such as are found in preeclampsia.

Risk factors include carrying more than one fetus, chronic high blood pressure, type 1 or 2 diabetes, kidney disease, autoimmune disorders before pregnancy as well as the use of in vitro fertilization . Rising rates of preeclampsia are primarily attributed to obesity, which is a risk factor for many of these conditions and associated with high levels of aldosterone and leptin, Faulkner said. Other times, women seem to develop the problem spontaneously. (ANI)

(This story has not been edited by the Devdiscourse team and is auto-generated from a syndicated feed.)

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