Posts tagged estrogen
Articles and news from the latest research reports.
Memory decline — a frequent complaint of menopausal women — potentially could be lessened by hypnotic relaxation therapy, say Baylor University researchers, who already have done studies showing that such therapy eases hot flashes, improves sleep and reduces stress in menopausal women.
Their review — “Memory Decline in Peri- and Post-menopausal Women: The Potential of Mind-Body Medicine to Improve Cognitive Performance” — is published in the journal Integrative Medicine Insights. October has been designated World Menopause Month by the International Menopause Society.
Initial research by Baylor, funded by the National Institutes of Health, focused on hot flashes, finding that hypnotic relaxation therapy lessened them, but “along the way, we discovered there are a lot of secondary benefits, including significantly improved sleep and mood,” said Jim R. Sliwinski, a doctoral student in the department of psychology and neuroscience in Baylor’s College of Arts & Sciences.
Co-researcher Gary Elkins, Ph.D., theorizes that sleep, mood and hot flashes associated with decreased estrogen also have a bearing on memory. Their publication, which reviews previous research by other scholars, proposes a framework for how mind-body interventions may improve memory, which could prove fruitful in doing future research.
“Memory decline may not be solely about decreased estrogen,” said Elkins, director of Baylor’s Mind-Body Medicine Research Laboratory and a professor of psychology and neuroscience.
Peri- and post-menopausal women may find mind-body therapies attractive for many reasons, among them that they do not have the side effects of medications or hormone therapy, said Elkins, author of “Relief from Hot Flashes: The Natural, Drug-Free Program to Reduce Hot Flashes, Improve Sleep and Ease Stress.”
While hormone therapy can increase estrogen, it also is associated with an increased risk of breast cancer and cardiovascular disease for some women, he said.
Researchers have noted that while memory decline can occur with aging in both men and women, women are more likely to report a greater number of memory problems, associating it with estrogen decline. Women also report more concerns about memory than pre-menopausal women do, according to several large-scale survey studies.
A factor that may impact memory is that women are dealing with increased responsibilities, stress or depression over such issues as caring for aging parents. In addition, their concern about memory problems may cause them to be more aware of memory lapses, Sliwinski said.
Even women who can safely be treated with estrogen do not necessarily have improved memory. “It sometimes even is associated with cognition problems,” he said.
Although there are questions about sleep’s specific role in forming and storing memories, researchers generally agree that consolidated sleep throughout a whole night is optimal for learning and memory.
Memory tests and scores over time with study participants — both pre-and post-menopausal — could help shed light on how menopause affects recollection, the Baylor researchers said.
(Image: Shutterstock)
Estrogen receptor expression may help explain why more males have autism
The same sex hormone that helps protect females from stroke may also reduce their risk of autism, scientists say.
In the first look at a potential role of the female sex hormone in autism, researchers at the Medical College of Georgia at Georgia Regents University have found expression of estrogen receptor beta – which enables estrogen’s potent brain protection – is significantly decreased in autistic brains. The receptor also plays a role in locomotion as well as behavior, including anxiety, depression, memory, and learning.
"If you ask any psychiatrist seeing patients with autistic behavior their most striking observation from the clinic, they will say there are more males compared to females," said Dr. Anilkumar Pillai, MCG neuroscientist and corresponding author of the study in Molecular Autism.
Estrogen is known to help protect premenopausal women from maladies such as stroke and impaired cognition. Exposure to high levels of the male hormone testosterone during early development has been linked to autism, which is five times more common in males than females.
The new findings of reduced expression of estrogen receptor beta as well as that of an enzyme that converts testosterone to estrogen could help explain the high testosterone levels in autistic individuals and higher autism rates in males, Pillai said.
It was the 5-to-1 male-to-female ratio along with the testosterone hypothesis that led Pillai and his colleagues to pursue whether estrogen might help explain the significant gender disparity and possibly point toward a new treatment.
"The testosterone hypothesis is already there, but nobody had investigated whether it had anything to do with the female hormone in the brain," Pillai said. "Estrogen is known to be neuroprotective, but nobody has looked at whether its function is impaired in the brain of individuals with autism. We found that the children with autism didn’t have sufficient estrogen receptor beta expression to mediate the protective benefits of estrogen."
Comparing the brains of 13 children with and 13 children without autism spectrum disorder, the researchers found a 35 percent decrease in estrogen receptor beta expression as well as a 38 percent reduction in the amount of aromatase, the enzyme that converts testosterone to estrogen.
Levels of estrogen receptor beta proteins, the active molecules that result from gene expression and enable functions like brain protection, were similarly low. There was no discernable change in expression levels of estrogen receptor alpha, which mediates sexual behavior.
The study focused on the brain’s prefrontal cortex, which is involved in social behavior and cognition. Brain tissue from both autistic and healthy subjects was obtained from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Brain and Tissue Bank for Developmental Disorders at the University of Maryland. The children died at an average age of 11 from drowning, other accidents, or suicide. All the brain tissue was from male children except for one control.
While much work remains, estrogen receptor beta agonists, which are already known to improve brain plasticity and memory in animals, might one day help reverse autism’s behavioral deficits, such as reclusiveness and repetitive behavior, Pillai said.
The scientists already are moving to animal studies to see what happens when they reduce estrogen receptor beta expression in mice. They also plan to give an estrogen receptor beta agonist – which should increase receptor function – to a mouse with generalized inflammation and signs of autism to see if it mitigates those signs. Inflammation is a factor in many diseases of the brain and body, and estrogen receptor beta agonists already are in clinical trials for schizophrenia
Larger, follow-up studies should also include comparing expression of testosterone receptor levels in healthy and autistic children, Pillai said. MCG scientists also want to know more about why the reduced beta receptor expression occurs.
Studies published in the journal Molecular Psychiatry earlier this year by scientists at the University of Cambridge and Denmark’s Statens Serum Institute showed that male children who develop autism were exposed to higher levels of steroid hormones, including testosterone and progesterone, during development than their healthy peers.
The incidence of autism has increased about 30 percent in the past two years in the United States, to the current rate of about 1 in 68 children, according to the Centers for Disease Control and Prevention. Most children are diagnosed at about age 4, although the disorder can be diagnosed by about age 2, according to the CDC. Diagnosis is made through extensive behavioral and psychological testing.
(Source: eurekalert.org)
Music can be soothing or stirring, it can make us dance or make us sad. Blood pressure, heartbeat, respiration and even body temperature – music affects the body in a variety of ways. It triggers especially powerful physical reactions in pregnant women. Scientists at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig have discovered that pregnant women compared to their non-pregnant counterparts rate music as more intensely pleasant and unpleasant, associated with greater changes in blood pressure. Music appears to have an especially strong influence on pregnant women, a fact that may relate to a prenatal conditioning of the fetus to music.
For their study, the Max Planck researchers played short musical sequences of 10 or 30 seconds’ duration to female volunteers. They changed the passages and played them backwards or incorporated dissonances. By doing so, they distorted the originally lively instrumental pieces and made listening to them less pleasant.
The pregnant women rated the pieces of music slightly differently, they perceived the pleasant music as more pleasant and the unpleasant as more unpleasant. The blood pressure response to music was much stronger in the pregnant group. Forward-dissonant music produced a particularly pronounced fall in blood pressure, whereas backwards-dissonant music led to a higher blood pressure after 10 seconds and a lower one after 30 seconds. “Thus, unpleasant music does not cause an across-the-board increase in blood pressure, unlike some other stress factors”, says Tom Fritz of the Max Planck Institute in Leipzig. “Instead, the body’s response is just as dynamic as the music itself.”
According to the results, music is a very special stimulus for pregnant women, to which they react strongly. “Every acoustic manipulation of music affects blood pressure in pregnant women far more intensely than in non-pregnant women”, says Fritz. Why music has such a strong physiological influence on pregnant woman is still unknown. Originally, the scientists suspected the hormone oestrogen to play a mayor part in this process, because it has an influence on the brain’s reward system, which is responsible for the pleasant sensations experienced while listening to music. However, non-pregnant women showed constant physiological responses throughout the contraceptive cycle, which made them subject to fluctuations in oestrogen levels. “Either oestrogen levels are generally too low in non-pregnant women, or other physiological changes during pregnancy are responsible for this effect”, explains Fritz.
The researchers suspect that foetuses are conditioned to music perception while still in the womb by the observed intense physiological music responses of the mothers. From 28 weeks, i.e. at the start of the third trimester of pregnancy, the heart rate of the foetus already changes when it hears a familiar song. From 35 weeks, there is even a change in its movement patterns.
Researchers Discover the Seat of Sex and Violence in the Brain
As reported in a paper published online today in the journal Nature, Caltech biologist David J. Anderson and his colleagues have genetically identified neurons that control aggressive behavior in the mouse hypothalamus, a structure that lies deep in the brain (orange circle in the image). Researchers have long known that innate social behaviors like mating and aggression are closely related, but the specific neurons in the brain that control these behaviors had not been identified until now.
The interdisciplinary team of graduate students and postdocs, led by Caltech senior research fellow Hyosang Lee, found that if these neurons are strongly activated by pulses of light, using a method called optogenetics, a male mouse will attack another male or even a female. However, weaker activation of the same neurons will trigger sniffing and mounting: mating behaviors. In fact, the researchers could switch the behavior of a single animal from mounting to attack by gradually increasing the strength of neuronal stimulation during a social encounter (inhibiting the neurons, in contrast, stops these behaviors dead in their tracks).
These results suggest that the level of activity within the population of neurons may control the decision between mating and fighting.
The neurons initially were identified because they express a protein receptor for the hormone estrogen, reinforcing the view that estrogen plays an important role in the control of male aggression, contrary to popular opinion. Because the human brain contains a hypothalamus that is structurally similar to that in the mouse, these results may be relevant to human behavior as well.
Estrogen: Not just produced by the ovaries
A UW-Madison research team reports today that the brain can produce and release estrogen — a discovery that may lead to a better understanding of hormonal changes observed from before birth throughout the entire aging process.
The new research shows that the hypothalamus can directly control reproductive function in rhesus monkeys and very likely performs the same action in women.
Scientists have known for about 80 years that the hypothalamus, a region in the brain, is involved in regulating the menstrual cycle and reproduction. Within the past 40 years, they predicted the presence of neural estrogens, but they did not know whether the brain could actually make and release estrogen.
Most estrogens, such as estradiol, a primary hormone that controls the menstrual cycle, are produced in the ovaries. Estradiol circulates throughout the body, including the brain and pituitary gland, and influences reproduction, body weight, and learning and memory. As a result, many normal functions are compromised when the ovaries are removed or lose their function after menopause.
"Discovering that the hypothalamus can rapidly produce large amounts of estradiol and participate in control of gonadotropin-releasing hormone neurons surprised us," says Ei Terasawa, professor of pediatrics at the UW School of Medicine and Public Health and senior scientist at the Wisconsin National Primate Research Center. "These findings not only shift the concept of how reproductive function and behavior is regulated but have real implications for understanding and treating a number of diseases and disorders."
For diseases that may be linked to estrogen imbalances, such as Alzheimer’s disease, stroke, depression, experimental autoimmune encephalomyelitis and other autoimmune disorders, the hypothalamus may become a novel area for drug targeting, Terasawa says. “Results such as these can point us in new research directions and find new diagnostic tools and treatments for neuroendocrine diseases.”
The study, published today in the Journal of Neuroscience, “opens up entirely new avenues of research into human reproduction and development, as well as the role of estrogen action as our bodies age,” reports the first author of the paper, Brian Kenealy, who earned his Ph.D. this summer in the Endocrinology and Reproductive Physiology Program at UW-Madison. Kenealy performed three studies. In the first experiment, a brief infusion of estradiol benzoate administered into the hypothalamus of rhesus monkeys that had surgery to remove their ovaries rapidly stimulated GnRH release. The brain took over and began rapidly releasing this estrogen in large pulsing surges.
In the second experiment, mild electrical stimulation of the hypothalamus caused the release of both estrogen and GnRH (thus mimicking how estrogen could induce a neurotransmitter-like action). Third, the research team infused letrazole, an aromatase inhibitor that blocks the synthesis of estrogen, resulting in a lack of estrogen as well as GnRH release from the brain. Together, these methods demonstrated how local synthesis of estrogen in the brain is important in regulating reproductive function.
The reproductive, neurological and immune systems of rhesus macaques have proven to be excellent biomedical models for humans over several decades, says Terasawa, who focuses on the neural and endocrine mechanisms that control the initiation of puberty. “This work is further proof that these animals can teach us about so many basic functions we don’t fully understand in humans.”
Leading up to this discovery, Terasawa said, recent evidence had shown that estrogen acting as a neurotransmitter in the brain rapidly induced sexual behavior in quails and rats. Kenealy’s work is the first evidence of this local hypothalamic action in primates, and in those that don’t even have ovaries.
"The discovery that the primate brain can make estrogen is key to a better understanding of hormonal changes observed during every phase of development, from prenatal to puberty, and throughout adulthood, including aging," Kenealy says.
(Source: news.wisc.edu)
Menstrual Cycle Influences Concussion Outcomes
Researchers found that women injured during the two weeks leading up to their period (the premenstrual phase) had a slower recovery and poorer health one month after injury compared to women injured during the two weeks directly after their period or women taking birth control pills.
The University of Rochester study was published today in the Journal of Head Trauma Rehabilitation. If confirmed in subsequent research, the findings could alter the treatment and prognosis of women who suffer head injuries from sports, falls, car accidents or combat.
Several recent studies have confirmed what women and their physicians anecdotally have known for years: Women experience greater cognitive decline, poorer reaction times, more headaches, extended periods of depression, longer hospital stays and delayed return-to-work compared to men following head injury. Such results are particularly pronounced in women of childbearing age; girls who have not started their period and post-menopausal women have outcomes similar to men.
Few studies have explored why such differences occur, but senior author Jeffrey J. Bazarian, M.D., M.P.H. says it stands to reason that sex hormones such as estrogen and progesterone, which are highest in women of childbearing age, may play a role.
“I don’t think doctors consider menstrual history when evaluating a patient after a concussion, but maybe we should,” noted Bazarian, associate professor of Emergency Medicine at the University of Rochester School of Medicine and Dentistry who treats patients and conducts research on traumatic brain injury and long-term outcomes among athletes. “By taking into account the stage of their cycle at the time of injury we could better identify patients who might need more aggressive monitoring or treatment. It would also allow us to counsel women that they’re more – or less – likely to feel poorly because of their menstrual phase.”
Although media coverage tends to focus on concussions in male professional athletes, studies suggest that women have a higher incidence of head injuries than men playing sports with similar rules, such as ice hockey, soccer and basketball. Bazarian estimates that 70 percent of the patients he treats in the URMC Sport Concussion Clinic are young women. He believes the number is so high because they often need more follow-up care. In his experience, soccer is the most common sport leading to head injuries in women, but lacrosse, field hockey, cheerleading, volleyball and basketball can lead to injuries as well.
Sex hormone levels often change after a head injury, as women who have suffered a concussion and subsequently missed one or more periods can attest. According to Kathleen M. Hoeger, M.D., M.P.H., study co-author and professor of Obstetrics and Gynecology at the University of Rochester School of Medicine and Dentistry, any stressful event, like a hit to the head, can shut down the pituitary gland in the brain, which is the body’s hormone generator. If the pituitary doesn’t work, the level of estrogen and progesterone would drop quickly.
According to Bazarian, progesterone is known to have a calming effect on the brain and on mood. Knowing this, his team came up with the “withdrawal hypothesis”: If a woman suffers a concussion in the premenstrual phase when progesterone levels are naturally high, an abrupt drop in progesterone after injury produces a kind of withdrawal which either contributes to or worsens post concussive symptoms like headache, nausea, dizziness and trouble concentrating. This may be why women recover differently than men, who have low pre-injury levels of the hormone.
Hoeger and Bazarian tested their theory by recruiting144 women ages 18 to 60 who arrived within four hours of a head hit at five emergency departments in upstate New York and one in Pennsylvania. Participants gave blood within six hours of injury and progesterone level determined the menstrual cycle phase at the time of injury. Based on the results, participants fell into three groups: 37 in the premenstrual/high progesterone group; 72 in the low progesterone group (progesterone is low in the two weeks directly after a period); and 35 in the birth control group based on self-reported use.
One month later, women in the premenstrual/high progesterone group were twice as likely to score in a worse percentile on standardized tests that measure concussion recovery and quality of life – as defined by mobility, self-care, usual activity, pain and emotional health – compared to women in the low progesterone group. Women in the premenstrual/high progesterone group also scored the lowest (average 65) on a health rating scale that went from 0, being the worst health imaginable, to 100, being the best. Women in the birth control group had the highest scores (average 77).
“If you get hit when progesterone is high and you experience a steep drop in the hormone, this is what makes you feel lousy and causes symptoms to linger,” said Bazarian. “But, if you are injured when progesterone is already low, a hit to the head can’t lower it any further, so there is less change in the way you feel.”
The team suspected that women taking birth control pills, which contain synthetic hormones that mimic the action of progesterone, would have similar outcomes to women injured in the low progesterone phase of their cycle. As expected, there was no clear difference between these groups, as women taking birth control pills have a constant stream of sex hormones and don’t experience a drop following a head hit, so long as they continue to take the pill.
“Women who are very athletic get several benefits from the pill; it protects their bones and keeps their periods predictable,” noted Hoeger. “If larger studies confirm our data, this could be one more way in which the pill is helpful in athletic women, especially women who participate in sports like soccer that present lots of opportunities for head injuries.”
In addition to determining menstrual cycle phase at the time of injury, Bazarian plans to scrutinize a woman’s cycles after injury to make sure they are not disrupted. If they are, the woman should make an appointment with her gynecologist to discuss the change.
Study helps deconstruct estrogen’s role in memory
The loss of estrogens at menopause increases a woman’s risk of dementia and Alzheimer’s disease, yet hormone replacement therapy can cause harmful side effects.
Knowing the exact mechanism of estrogen activation in the brain could lead to new targets for drug development that would provide middle-aged women the cognitive benefits of hormone replacement therapy without increasing their risk for cardiovascular disease or breast cancer.
In a new study, Karyn Frick, professor of psychology at the University of Wisconsin-Milwaukee, uncovers details about estrogen’s role in the complex cellular communication system underlying memory formation.
“The receptor mechanisms that regulate estrogen’s ability to enhance memory are still poorly understood,” says Frick. “With this study, we’ve begun to sort out several of the key players needed for estrogens to mediate memory formation.”
The research, published in the The Journal of Neuroscience today, focused on estrogen effects in a brain region called the hippocampus, which deteriorates with age or Alzheimer’s disease. The researchers found that each of the two known estrogen receptors rapidly activate a specific cellular pathway necessary for memory formation in the hippocampus of female mice, but only if they interact with a certain glutamate receptor, called mGluR1.
The study revealed that when this glutamate receptor is blocked, the cell-signaling protein ERK cannot be activated by the potent estrogen, 17β-estradiol. Because ERK activation is necessary for memory formation, estradiol failed to enhance memory among mice in which mGluR1 was blocked.
Frick’s team also found evidence that estrogen receptors and mGluR1 physically interact at the cell membrane, allowing estradiol to influence memory formation within seconds to minutes. Collectively, the data provide the first evidence that the rapid signaling initiated by such interactions is essential for estradiol to enhance memory regulated by the hippocampus.
“Our data suggesting that interactions between estrogen receptors and mGluR1 at the cell membrane are critical for estradiol to enhance memory provides important new information about how estrogens regulate memory formation,” Frick says. “Because membrane proteins are better targets for drug development than proteins inside the cell, these data could lead to a new generation of therapies that provide the cognitive benefits of estrogens without harmful side effects.”
Females Respond Better to Stress Because of Estrogen in the Brain, Animal Study Finds
The idea that females are more resilient than males in responding to stress is a popular view, and now University at Buffalo researchers have found a scientific explanation. The paper describing their embargoed study will be published July 9 online, in the high-impact journal, Molecular Psychiatry.
“We have examined the molecular mechanism underlying gender-specific effects of stress,” says senior author Zhen Yan, PhD, a professor in the Department of Physiology and Biophysics in the UB School of Medicine and Biomedical Sciences. “Previous studies have found that females are more resilient to chronic stress and now our research has found the reason why.”
The research shows that in rats exposed to repeated episodes of stress, females respond better than males because of the protective effect of estrogen.
In the UB study, young female rats exposed to one week of periodic physical restraint stress showed no impairment in their ability to remember and recognize objects they had previously been shown. In contrast, young males exposed to the same stress were impaired in their short-term memory.
An impairment in the ability to correctly remember a familiar object signifies some disturbance in the signaling ability of the glutamate receptor in the prefrontal cortex, the brain region that controls working memory, attention, decision-making, emotion and other high-level “executive” processes.
Last year, Yan and UB colleagues published in Neuron a paper showing that repeated stress results in loss of the glutamate receptor in the prefrontal cortex of young males.
The current paper shows that the glutamate receptor in the prefrontal cortex of stressed females is intact. The findings provide more support for a growing body of research demonstrating that the glutamate receptor is the molecular target of stress, which mediates the stress response.
The stressors used in the experiments mimic challenging and stressful, but not dangerous, experiences that humans face, such as those causing frustration and feelings of being under pressure, Yan says.
By manipulating the amount of estrogen produced in the brain, the UB researchers were able to make the males respond to stress more like females and the females respond more like males.
“When estrogen signaling in the brains of females was blocked, stress exhibited detrimental effects on them,” explains Yan. “When estrogen signaling was activated in males, the detrimental effects of stress were blocked.
“We still found the protective effect of estrogen in female rats whose ovaries were removed,” says Yan. “It suggests that it might be estrogen produced in the brain that protects against the detrimental effects of stress.”
In the current study, Yan and her colleagues found that the enzyme aromatase, which produces estradiol, an estrogen hormone, in the brain, is responsible for female stress resilience. They found that aromatase levels are significantly higher in the prefrontal cortex of female rats.
“If we could find compounds similar to estrogen that could be administered without causing hormonal side effects, they could prove to be a very effective treatment for stress-related problems in males,” she says.
She notes that while stress itself is not a psychiatric disorder, it can be a trigger for the development of psychiatric disorders in vulnerable individuals.
(Source: newswise.com)
Brain Anatomy of Dyslexia Is Not the Same in Men and Women, Boys and Girls
Using MRI, neuroscientists at Georgetown University Medical Center found significant differences in brain anatomy when comparing men and women with dyslexia to their non-dyslexic control groups, suggesting that the disorder may have a different brain-based manifestation based on sex.
Their study, investigating dyslexia in both males and females,is the first to directly compare brain anatomy of females with and without dyslexia (in children and adults). Their findings were published online in the journal Brain Structure and Function.
Because dyslexia is two to three times more prevalent in males compared with females, “females have been overlooked,” says senior author Guinevere Eden, PhD, director for the Center for the Study of Learning and past-president of the International Dyslexia Association.
“It has been assumed that results of studies conducted in men are generalizable to both sexes. But our research suggests that researchers need to tackle dyslexia in each sex separately to address questions about its origin and potentially, treatment,” Eden says.
Previous work outside of dyslexia demonstrates that male and female brains are different in general, adds the study’s lead author, Tanya Evans, PhD.
“There is sex-specific variance in brain anatomy and females tend to use both hemispheres for language tasks, while males just the left,” Evans says. “It is also known that sex hormones are related to brain anatomy and that female sex hormones such as estrogen can be protective after brain injury, suggesting another avenue that might lead to the sex-specific findings reported in this study.”
The study of 118 participants compared the brain structure of people with dyslexia to those without and was conducted separately in men, women, boys and girls. In the males, less gray matter volume is found in dyslexics in areas of the brain used to process language, consistent with previous work. In the females, less gray matter volume is found in dyslexics in areas involved in sensory and motor processing.
The results have important implications for understanding the origin of dyslexia and the relationship between language and sensory processing, says Evans.
Hormone Combination Effective and Safe for Treating Obesity in Mice
Scientists at Indiana University and international collaborators have found a way to link two hormones into a single molecule, producing a more effective therapy with fewer side effects for potential use as treatment for obesity and related medical conditions.
The studies were carried out in the laboratories of Richard DiMarchi, the Standiford H. Cox Distinguished Professor of Chemistry and the Linda & Jack Gill Chair in Biomolecular Sciences in the IU Bloomington College of Arts and Sciences, and of Matthias Tschöp, professor of medicine and director of the Institute of Diabetes and Obesity, Helmholtz Center Munich, Germany. Results were published online this week by the journal Nature Medicine.
Researchers combined a peptide hormone from the digestive system, GLP-1, with the hormone estrogen and administered it to obese laboratory mice. While both GLP-1 and estrogen have demonstrated efficacy as therapy for obesity and adult-onset diabetes, the combination was more effective in producing weight loss and other beneficial results than using either compound on its own. And it produced fewer adverse effects, such as excessive tissue growth linked to tumor formation.
"We find that combining the hormones as a single molecule dramatically enhanced their efficacy and their safety," DiMarchi said. "The combination improves the ability to lower body weight and the ability to manage glucose, and it does so without showing the hallmark toxicities associated with estrogen."