Tag: sex differences

Women Get the Same Exercise Benefits as Men, but with Less Effort

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A new study from the Smidt Heart Institute at Cedars-Sinai shows there is a gender gap between women and men when it comes to exercise. The findings, published in the Journal of the American College of Cardiology (JACC), show that women can exercise less often than men, yet receive greater cardiovascular gains.

“Women have historically and statistically lagged behind men in engaging in meaningful exercise,” said Martha Gulati, MD, director of Preventive Cardiology in the Department of Cardiology in the Smidt Heart Institute at Cedars-Sinai, the Anita Dann Friedman Chair in Women’s Cardiovascular Medicine and Research and co-lead author of the study.

“The beauty of this study is learning that women can get more out of each minute of moderate to vigorous activity than men do. It’s an incentivising notion that we hope women will take to heart.”

Investigators analysed data from 412 413 US adults utilising the National Health Interview Survey database. Participants between the time frame of 1997 to 2019 – 55% of whom were female – provided survey data on leisure-time physical activity.

Investigators examined gender-specific outcomes in relation to frequency, duration, intensity and type of physical activity.

“For all adults engaging in any regular physical activity, compared to being inactive, mortality risk was expectedly lower,” said Susan Cheng, MD, MPH, the Erika J. Glazer Chair in Women’s Cardiovascular Health and Population Science, director of the Institute for Research on Healthy Aging in the Department of Cardiology in the Smidt Heart Institute, and senior author of the study.

“Intriguingly, though, mortality risk was reduced by 24% in women and 15% in men.”

The research team then studied moderate to vigorous aerobic physical activity, such as brisk walking or cycling, and found that men reached their maximal survival benefit from doing this level of exercise for about five hours per week, whereas women achieved the same degree of survival benefit from exercising just under about 2 ½ hours per week.

Similarly, when it came to muscle-strengthening activity, such as weightlifting or core body exercises, men reached their peak benefit from doing three sessions per week and women gained the same amount of benefit from about one session per week.

Cheng said that women had even greater gains if they engaged in more than 2 ½ hours per week of moderate to vigorous aerobic activity, or in two or more sessions per week of muscle-strengthening activities.

The investigators note their findings help to translate a longstanding recognition of sex-specific physiology seen in the exercise lab to a now-expanded view of sex differences in exercise-related clinical outcomes.

With all types of exercise and variables accounted for, Gulati says there’s power in recommendations based on the study’s findings.

“Men get a maximal survival benefit when performing 300 minutes of moderate to vigorous activity per week, whereas women get the same benefit from 140 minutes per week,” Gulati said.

“Nonetheless, women continue to get further benefit for up to 300 minutes a week.”

Christine M. Albert, MD, MPH, chair of the Department of Cardiology in the Smidt Heart Institute and the Lee and Harold Kapelovitz Distinguished Chair in Cardiology, says concrete, novel studies like this don’t happen often.

“I am hopeful that this pioneering research will motivate women who are not currently engaged in regular physical activity to understand that they are in a position to gain tremendous benefit for each increment of regular exercise they are able to invest in their longer-term health,” said Albert, professor of Cardiology.

Source: Cedars-Sinai Medical Center

COVID, Opioid Pandemic Widen Gender Gap in Life Expectancy in the US

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Women have long been known to outlive men. But new research published in JAMA Internal Medicine shows that, at least in the United States, the gap has been widening for more than a decade. Among the factors driving the trend are the COVID pandemic and the opioid overdose epidemic.

The study, led by UC San Francisco and Harvard T.H. Chan School of Public Health, found the difference between how long American men and women live increased to 5.8 years in 2021, the largest since 1996. This is an increase from 4.8 years in 2010, when the gap was at its smallest in recent history.

The pandemic, which took a disproportionate toll on men, was the biggest contributor to the widening gap from 2019–2021, followed by unintentional injuries and poisonings (mostly drug overdoses), accidents and suicide.

“There’s been a lot of research into the decline in life expectancy in recent years, but no one has systematically analysed why the gap between men and women has been widening since 2010,” said the paper’s first author, Brandon Yan, MD, MPH, a UCSF internal medicine resident physician and research collaborator at Harvard Chan School.

Life expectancy in the US dropped in 2021 to 76.1 years, falling from 78.8 years in 2019 and 77 years in 2020.

The shortening lifespan of Americans has been attributed in part to so-called “deaths of despair.” The term refers to the increase in deaths from such causes as suicide, drug use disorders and alcoholic liver disease, which are often connected with economic hardship, depression and stress.

“While rates of death from drug overdose and homicide have climbed for both men and women, it is clear that men constitute an increasingly disproportionate share of these deaths,” Yan said.

Interventions to reverse a deadly trend

Using data from the National Center for Health Statistics, Yan and fellow researchers from around the country identified the causes of death that were lowering life expectancy the most. Then they estimated the effects on men and women to see how much different causes were contributing to the gap.

Prior to the COVID pandemic, the largest contributors were unintentional injuries, diabetes, suicide, homicide and heart disease.

But during the pandemic, men were more likely to die of the virus. That was likely due to a number of reasons, including differences in health behaviours, as well as social factors, such as the risk of exposure at work, reluctance to seek medical care, incarceration and housing instability. Chronic metabolic disorders, mental illness and gun violence also contributed.

Yan said the results raise questions about whether more specialised care for men, such as in mental health, should be developed to address the growing disparity in life expectancy.

“We have brought insights to a worrisome trend,” Yan said. “Future research ought to help focus public health interventions towards helping reverse this decline in life expectancy.”

Yan and co-authors, including senior author Howard Koh, MD, MPH, professor of the practice of public health leadership at Harvard Chan School, also noted that further analysis is needed to see if these trends change after 2021.

“We need to track these trends closely as the pandemic recedes,” Koh said. “And we must make significant investments in prevention and care to ensure that this widening disparity, among many others, do not become entrenched.”

Source: University of California – San Francisco

Females Less Able to Recover from ACL Injuries

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Injuries of the knee’s anterior cruciate ligament (ACL) are typically thought to be caused by acute traumatic events, such as sudden twists. Published in the Journal of Orthopaedic Research, new work analysing an animal model of ACLs suggests that such injuries can also occur as a result of chronic overuse, specifically due to a reduced ability to repair microtraumas associated with overuse. Importantly, the team said, females also are less able to heal from these microtraumas than males, which may explain why females are two to eight times more likely to tear their ACL ligaments than males.

“ACL tears are one of the most common injuries, affecting more than 200 000 people in the US each year, and women are known to be particularly susceptible,” said principal investigator Spencer Szczesny, associate professor of biomedical engineering and of orthopaedics and rehabilitation at Penn State. “While recent research suggests that chronic overuse can lead to ACL injuries, until now, no one had investigated the differential biological response of female and male ACLs to applied force.”

In the Penn State-led study, researchers placed ACLs from deceased male and female rabbits in a custom-made bioreactor that simulated the conditions of a living animal but allowed direct observation and measurement of the tissue. Next, they applied repetitive forces to the ACLs that mimicked those that would naturally occur during activities such as standing, walking and trotting and measured the expression of genes related to healing.

In male samples, the team found that low and moderate applied forces, such as those that would occur during standing or walking, resulted in increased expression of anabolic genes, which are related to building molecules needed for healing. By contrast, larger applied forces, such as those that would occur with repetitive trotting, decreased expression of these anabolic genes. For female samples, however, the amount of force applied did not influence the level of anabolic gene expression.

“It didn’t matter whether there was low, medium or high activity for females,” said Lauren Paschall, graduate student in biomedical engineering at Penn State and first author on the paper. “Female ACLs exposed to chronic use just didn’t heal as well as male ACLs, which may explain why women are predisposed to injuries. This supports the hypothesis that noncontact ACL injuries are attributed to microtraumas associated with chronic overuse that predispose the ACL to injury.”

According to the researchers, one explanation for the sex differences the team observed could be due to the higher amounts of oestrogen in females.

“Some studies have found that the overall effect of oestrogen on ACL injury is negative,” Paschall said. “Specifically, studies have shown that human women are more likely to tear their ACLs during the preovulatory phase, when oestrogen levels are high, than during the postovulatory phase, when oestrogen levels are low.”

She said the team plans to further investigate the role of oestrogen on ACL injury.

Szczesny noted that although the team’s study was not in humans, the findings may suggest that providing additional recovery time for women following injuries could be advantageous.

“Ultimately, this work could also help to identify targets for therapeutics to prevent ACL injuries in women,” he said.

Source: Penn State

Study Suggests Lowering Type 2 Diabetes Diagnosis Threshold in Women under 50

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New research published in the journal Diabetes Therapy suggests that the diagnosis threshold for type 2 diabetes (T2D) should be lowered in women aged under 50 years, since natural blood loss through menstruation could be affecting their blood sugar management.

Analysis of the national diabetes audit results has shown that women of younger age with type 2 diabetes mellitus (T2D) seem to have a higher mortality rate than men. The underlying mechanisms remain unclear. However, it is known that women are on average diagnosed with T2D at a later age than men. In this new study, the authors investigated whether a contributing factor to this late diagnosis may be a sex difference in the levels of glycated haemoglobin (HbA1c) due to haemoglobin replacement linked to menstrual blood loss.

This mechanism behind this could be shorter erythrocyte (red blood cell) survival which results in shorter exposure of haemoglobin to glucose compared with individuals who do not menstruate. Given that the diagnosis of T2D is also based on HbA1c, the use of the same reference range irrespective of age and sex, when a slightly lower point for T2D for premenopausal women may be appropriate, could potentially lead to under diagnosis of T2D in women and missed opportunities for intervention.

The study, by Dr Adrian Heald, Salford Royal Hospital, UK, and colleagues, examined HbA1c testing across seven UK laboratory sites (representing 5% of UK population). They conducted an exploratory analysis in two cohorts: cohort 1 was from one laboratory tested between 2012 and 2019 (146 907 participants). They assessed the sex and age differences of HbA1c in individuals who underwent single testing only, that had not been diagnosed with diabetes and had an HbA1c result of equal to or less than 48mmol/mol (the cutoff for diagnosing diabetes). The process was replicated in cohort 2 results from six laboratories with individuals tested between 2019 and 2021 (total people included 938 678). The possible national impact was estimated by extrapolating findings based on the Office of National Statistics (ONS) England population data and National Diabetes Audit published T2D prevalence and related excess mortality.

At age 50 years, average HbA1c levels in women lag by approximately five years compared to men. The data also show women aged under 50 years old had an HbA1c distribution that was lower than that of men by an average of 1.6mmol/mol (4.7% of the overall mean) while the difference in the distribution of HbA1c for individuals aged 50 years and over was less pronounced.  Further analysis showed that, at HbA1c of 48mmol/mol, 50% fewer women could be diagnosed with T2D than men under the age of 50, whilst only 20% fewer women could be diagnosed with T2D than men over or equal to the age of 50. These findings were consistent with those in cohort 2.

Based on these observations, the authors estimated the effects of lowering the threshold for diagnosis of diabetes from HbA1c (48mmol/mol) by 4.2% to 46mmol/mol for women under the age of 50. This analysis showed that an additional 35 345 currently undiagnosed women in England would be reclassified as being diagnosed with T2D (17% more than the current 208 000 recorded women with T2D aged under 50 years). Lifestyle changes and treatment for diabetes would then be initiated for these women enabling improvement in health outcomes over both the short and longer term.

The authors also highlight that sex and gender difference in adverse cardiovascular risk factors are known to be present prior to the development of T2D. Once diagnosed, the prevalence of atherosclerotic cardiovascular disease is twice as high in patients with diabetes mellitus compared to those without diabetes mellitus. For women, diabetes mellitus is a stronger risk factor for cardiovascular disease than for men: women with diabetes aged 35–59 years have the highest relative cardiovascular death risk across all age and sex groups.

Furthermore, there is disparity in cardiovascular risk factor management between men and women, including in high-risk groups such as women with T2D.  Women are less likely than men to receive treatment and cardiovascular risk reduction interventions that are recommended by international guidelines on diabetes. In addition, concordance with medication or prescription treating cardiovascular risk factors is lower in women than men with T2D, with less use of statins, aspirin and beta blockers. The authors say taken together, these factors mean “timely diagnosis of type 2 diabetes and initiation of preventative treatment has the potential to improve cardiovascular risk profile over lifetime and facilitate longer life quality and expectancy in women. Our findings provide evidence that the HbA1c threshold for this group should be re-evaluated.”

Source: EurekAlert!

A New Model of the Liver Will Help Improve Drug Safety for Women

Improved modelling of male and female livers can help lead to safer drugs

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Researchers report in PLOS Computational Biology that they developed a powerful new tool to understand how medications affect men and women differently, and that will help lead to safer, more effective drugs in the future.

Women are known to suffer a disproportionate number of liver problems from medications but also usually underrepresented in drug testing. To address this, University of Virginia scientists have developed sophisticated computer simulations of male and female livers and used them to reveal sex-specific differences in how the tissues are affected by drugs.

The new model has already provided unprecedented insights into the biological processes that take place in the liver, the organ responsible for detoxifying the body, in both men and women. But the model also represents a powerful new tool for drug development, helping ensure that new medications will not cause harmful side effects.

“There are incredibly complex networks of genes and proteins that control how cells respond to drugs,” said UVA researcher Jason Papin, PhD, one of the model’s creators. “We knew that a computer model would be required to try to answer these important clinical questions, and we’re hopeful these models will continue to provide insights that can improve healthcare.”

Harmful side effects

Papin, of UVA’s Department of Biomedical Engineering, developed the model in collaboration with Connor Moore, a PhD student, and Christopher Holstege, MD, a UVA emergency medicine physician and director of UVA Health’s Blue Ridge Poison Center. “It is exceedingly important that both men and women receive the appropriate dose of recommended medications,” Holstege noted. “Drug therapy is complex and toxicity can occur with subtle changes in dose for specific individuals.”

Before developing their model, the researchers first looked at the federal Food and Drug Administration’s Adverse Event Reporting System to evaluate the frequency of reported liver problems in men and women. The scientists found that women consistently reported liver-related adverse events more often than did men.

The researchers then sought to explain why this might be the case. To do that, they developed computer models of the male and female livers that integrated vast amounts of data on gene activity and metabolic processes within cells. These cutting-edge liver simulations provided important insights into how drugs (xenobiotics) affect the tissue differently in men and women and allowed the researchers to understand why.

They found that xenobiotic metabolism was more active in untreated males, while pentose and glucoronate interconversions were female-biased, suggesting a difference in pretreatment gene expression, which may result in different initial responses of phase I and phase II metabolism to hepatotoxic drugs. They also observed sex-bias in bile acid biosynthesis, which in combination with xenobiotic metabolism, this result may suggest differences in bacterial deconjugation driven by sex differences in the gut microbiome. Differences were also found in several essential metabolic pathways, such as glycolysis/gluconeogenesis, nucleotide metabolism, and lipid metabolism with supporting evidence in human or rat hepatocytes.

“We were surprised how many differences we found, especially in very diverse biochemical pathways,” said Moore, a biomedical engineering student in Papin’s lab. “We hope our results emphasise how important it is for future scientists to consider how both men and women are affected by their research.”

The work has already identified a key series of cellular processes that explain sex differences in liver damage, and the scientists are calling for more investigation of it to better understand “hepatotoxicity” — liver toxicity. Ultimately, they hope their model will prove widely useful in developing safer drugs.

“We’re hopeful these approaches will be help address many other questions where men and women have differences in drug responses or disease processes,” Papin said. “Our ability to build predictive computer models of complex systems in biology, like those in this study, is truly opening all kinds of new avenues for tackling some of the most challenging biomedical problems.”

Source: University of Virginia Health System

Diet Extremes of Carbohydrate and Fat Tied to Sex-specific Mortality Risks

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New research suggests that extreme dietary habits involving carbohydrates and fats affect life expectancy. Results published in The Journal of Nutrition show that a low carbohydrate intake in men and a high carbohydrate intake in women are associated with a higher risk of all-cause and cancer-related mortality and that women with higher fat intake may have a lower risk of all-cause mortality. Their findings suggest that people should pursue a balanced diet rather than heavily restricting their carbohydrate or fat intake.

While low-carbohydrate and low-fat diets are becoming popular as a way to promote weight loss and improve blood glucose levels, their long-term effects on life expectancy are less clear. Interestingly, recent studies conducted in Western countries suggest that extreme dietary habits for carbohydrates and fats are associated with a higher risk of mortality. However, few studies have explored these associations in East Asian populations, including Japanese individuals who typically have relatively low fat and high-carbohydrate dietary intakes.

Researchers from Nagoya University Graduate School of Medicine in Japan led by Dr Takashi Tamura conducted a follow-up survey over a period of 9 years with 81 333 Japanese people (34,893 men and 46 440 women) to evaluate the association between carbohydrate and fat intakes and the risk of mortality. Daily dietary intakes of carbohydrates, fats, and total energy were estimated using a food frequency questionnaire and calculated as a percentage of total energy intake for carbohydrates and fats. Carbohydrate intake quality (ie, refined compared with minimally processed carbohydrate intake) and fat intake quality (ie, saturated compared with unsaturated fat intake) were also assessed to examine the impact of food quality on the association with mortality.

They found that men who consumed less than 40% of their total energy from carbohydrates experienced significantly higher risks of all-cause and cancer-related mortality. The trend was observed regardless of whether refined or minimally processed carbohydrate were considered. On the other hand, among women with 5 years or longer of follow-up, those with a high carbohydrate intake of more than 65% had a higher risk of all-cause mortality. No clear association was observed between refined or minimally processed carbohydrate intake and the risk of mortality in women.

For fats, men with a high fat intake of more than 35% of their total energy from fats had a higher risk of cancer-related mortality. They also found that a low intake of unsaturated fat in men was associated with a higher risk of all-cause and cancer-related mortality. In contrast, total fat intake and saturated fat intake in women showed an inverse association with the risk of all-cause and cancer-related mortality. They concluded that this finding does not support the idea that high fat intake is detrimental to longevity in women.

“The finding that saturated fat intake was inversely associated with the risk of mortality only in women might partially explain the differences in the associations between the sexes,” Dr Tamura stated. “Alternatively, components other than fat in the food sources of fat may be responsible for the observed inverse association between fat intake and mortality in women.”

This study is extremely important because restricting carbohydrates and fats, such as extremely low-carbohydrate and low-fat diets, are now popular dieting strategies aimed at improving health, including the management of metabolic syndrome. However, this study shows that low-carbohydrate and low-fat diets may not be the healthiest strategy for promoting longevity, as their short-term benefits could potentially be outweighed by long-term risk.

Overall, an unfavourable association with mortality was observed for low-carbohydrate intake in men and for high carbohydrate intake in women, whereas high fat intake could be associated with a lower mortality risk in women. The findings suggest that individuals should carefully consider how to balance their diet and ensure that they are taking in energy from a variety of food sources, while avoiding extremes.

Source: Nagoya University

Women Have Double the Mortality Risk After Heart Attack

The risk of dying after a heart attack is more than twice as high for women than it is for men, according to research presented at Heart Failure 2023, held by the European Society of Cardiology (ESC).

“Women of all ages who experience a myocardial infarction are at particularly high risk of a poor prognosis,” said study author Dr Mariana Martinho of Hospital Garcia de Orta. “These women need regular monitoring after their heart event, with strict control of blood pressure, cholesterol levels and diabetes, and referral to cardiac rehabilitation. Smoking levels are rising in young women and this should be tackled, along with promoting physical activity and healthy living.”

Previous studies have found that women with ST-elevation myocardial infarction (STEMI) have a worse prognosis during their hospital stay compared to men, and that this may be due to their older age, increased numbers of other conditions, and less use of stents (percutaneous coronary intervention; PCI) to open blocked arteries. This study compared short- and long-term outcomes after STEMI in women and men, and examined whether any sex differences were apparent in both premenopausal (55 years and under) and postmenopausal (over 55) women.

This was a retrospective observational study which enrolled consecutive patients admitted with STEMI and treated with PCI within 48 hours of symptom onset between 2010 and 2015. Adverse outcomes were defined as 30-day all-cause mortality, five-year all-cause mortality and five-year major adverse cardiovascular events (MACE; a composite of all-cause death, reinfarction, hospitalisation for heart failure and ischaemic stroke).

The study included 884 patients. The average age was 62 years and 27% were women. Women were older than men (average age 67 vs 60 years) and had higher rates of high blood pressure, diabetes and prior stroke. Men were more likely to be smokers and have coronary artery disease. The interval between symptoms and treatment with PCI did not differ between women and men overall, but women aged 55 and below had a significantly longer treatment delay after arriving at the hospital than their male peers (95 vs 80 minutes).

The researchers compared the risk of adverse outcomes between women and men after adjusting for factors that could influence the relationship including diabetes, high cholesterol, hypertension, coronary artery disease, heart failure, chronic kidney disease, peripheral artery disease, stroke and family history of coronary artery disease. At 30 days, 11.8% of women had died compared to 4.6% of men, for a hazard ratio (HR) of 2.76. At five years, nearly one-third of women (32.1%) had died versus 16.9% of men (HR 2.33). More than one-third of women (34.2%) experienced MACE within five years compared with 19.8% of men (HR 2.10).

Dr Martinho said: “Women had a two to three times higher likelihood of adverse outcomes than men in the short- and long-term even after adjusting for other conditions and despite receiving PCI within the same timeframe as men.”

The researchers conducted a further analysis in which they matched men and women according to risk factors for cardiovascular disease including hypertension, diabetes, high cholesterol and smoking. Adverse outcomes were then compared between matched men and women aged 55 years and under, and between matched men and women over 55 years old.

There were 435 patients in the matched analysis. In matched patients over 55 years of age, all adverse outcomes measured were more common in women than men. Some 11.3% of women died within 30 days compared with 3.0% of men, for an HR of 3.85. At five years, one-third of women (32.9%) had died compared with 15.8% of men (HR 2.35) and more than one-third of women (34.1%) had experienced MACE compared with 17.6% of men (HR 2.15). In matched patients aged 55 years and below, one in five women (20.0%) experienced MACE within five years compared to 5.8% of men (HR 3.91), while there were no differences between women and men in all-cause mortality at 30 days or five years.

Dr Martinho said: “Postmenopausal women had worse short- and long-term outcomes after myocardial infarction than men of similar age. Premenopausal women had similar short-term mortality but a poorer prognosis in the long-term compared with their male counterparts. While our study did not examine the reasons for these differences, atypical symptoms of myocardial infarction in women and genetic predisposition may play a role. We did not find any differences in the use of medications to lower blood pressure or lipid levels between women and men.”

She concluded: “The findings are another reminder of the need for greater awareness of the risks of heart disease in women. More research is required to understand why there is gender disparity in prognosis after myocardial infarction so that steps can be taken to close the gap in outcomes.”

Source: European Society of Cardiology

Young Males Most at Risk of Developing Schizophrenia from Cannabis Use

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A registry-based study on cannabis users in Denmark spanning 39 years found that young males were more than twice as likely to develop schizophrenia as young females. The researchers, who published their findings in Psychological Medicine, estimated that about 15% of schizophrenia in this population group is due to cannabis use.

Previous research suggests an increase in schizophrenia population attributable risk fraction (PARF) for cannabis use disorder (CUD). However, sex and age variations in CUD and schizophrenia suggest the importance of examining differences in PARFs in sex and age subgroups.

Moreover, cannabis potency measured by the percentage of delta-9-tetrahydrocannabinol (THC) (main psychoactive component of cannabis) has increased dramatically, eg from 13% in 2006 to 30% in 2016 in Denmark. CUD has also increased markedly – past-year CUD rose significantly from 4.9% in 2014 to 5.9% in 2018 among US 18–25-year-olds.

A growing body of evidence suggests that the relationship between CUD and schizophrenia may differ by sex. Male sex and early heavy or frequent cannabis use are associated with earlier onset of psychosis.

The researchers conducted a nationwide Danish register-based cohort study including all individuals aged 16–49 at some point during 1972–2021, identifying CUD and schizophrenia status.

The researchers examined 6 907 859 individuals, with 45 327 cases of incident schizophrenia during follow-up. Males had slightly higher risk for schizophrenia with CUD (142%) than females (102%). But among 16–20-year-olds, the risk for males (284%) was more than twice that for females (81%). They also found that during the 39-year study period, the annual average increase in PARF for CUD in schizophrenia incidence was 4.8% among males and 3.2% among females. In 2021, among males, this risk fraction was 15%; among females, it was around 4%.

Conclusions

The researchers concluded that “Young males might be particularly susceptible to the effects of cannabis on schizophrenia. At a population level, assuming causality, one-fifth of cases of schizophrenia among young males might be prevented by averting CUD. Results highlight the importance of early detection and treatment of CUD and policy decisions regarding cannabis use and access, particularly for 16–25-year-olds.”

Atherosclerosis is a Greater Heart Attack Risk for Women

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Postmenopausal women with atherosclerosis are at higher risk of heart attacks than men of similar age, according to research presented at EACVI 2023, a scientific congress of the European Society of Cardiology (ESC), and published in European Heart Journal – Cardiovascular Imaging. Researchers used imaging techniques to examine the arteries of nearly 25 000 patients and followed them for heart attacks and death.

“The study suggests that a given burden of atherosclerosis is riskier in postmenopausal women than it is in men of that age,” said study author Dr Sophie van Rosendael of Leiden University Medical Centre. “Since atherosclerotic plaque burden is emerging as a target to decide the intensity of therapy to prevent heart attacks, the findings may impact treatment. Our results indicate that after menopause, women may need a higher dose of statins or the addition of another lipid-lowering drug. More studies are needed to confirm these findings.”

While young women do have heart attacks, in general, women develop atherosclerosis (narrowing of arteries due to plaque buildup) later in life than men and have heart attacks at an older age than men, in part because of the protective effect of oestrogen. This study examined whether the prognostic importance of atherosclerotic plaques are the same for women and men at different ages as this could be important for selecting treatments to prevent heart attacks.

The study included 24 950 patients referred for coronary computed tomography angiography (CCTA) and enrolled in the CONFIRM registry, which was conducted in six countries in North America, Europe, and Asia. CCTA is used to obtain 3D images of the arteries in the heart.

Total atherosclerotic burden was rated using the Leiden CCTA score, which incorporates the following items for each coronary segment: plaque presence (yes/no), composition (calcified, noncalcified or mixed), location, and severity of narrowing, for a final value of 0 to 42. Patients were divided into three categories previously found to predict the risk myocardial infarction: low atherosclerotic burden (0 to 5), medium (6 to 20) and high (over 20). In addition, obstructive coronary artery disease was defined as 50% narrowing or more.

The primary outcome was the difference in Leiden CCTA score between women and men of similar age. The investigators also analysed sex differences in the rates of major adverse cardiovascular events (MACE), which included all-cause death and myocardial infarction, after adjusting for age and cardiovascular risk factors (hypertension, high cholesterol, diabetes, current smoking and family history of coronary artery disease).

A total of 11 678 women (average age 58.5 years) and 13 272 men (average age 55.6 years) were followed for 3.7 years. Regarding the primary outcome, the study showed an approximately 12 year delay in the onset of coronary atherosclerosis in women: the median Leiden CCTA risk score was above zero at age 64 to 68 years in women versus 52 to 56 years in men (p<0.001). In addition, the overall plaque burden as quantified by the Leiden CCTA score was significantly lower in women, who had more non-obstructive disease.

Dr. van Rosendael said: “The results confirm the previously reported delay in the start of atherosclerosis in women. We also found that women are more likely to have non-obstructive disease. It was formerly thought that only obstructive atherosclerosis caused myocardial infarction but we now know that non-obstructive disease is also risky.”
 
The burden of atherosclerosis was equally predictive of MACE in premenopausal women (aged under 55 years) and men of the same age group. However, in postmenopausal women (age 55 years and older), the risk of MACE was higher than men for a given score. In postmenopausal women, compared to those with a low burden, those with a medium and high burden had 2.21-fold and 6.11-fold higher risks of MACE. While in men aged 55 years and older, compared to those with a low burden, those with a medium and high burden had 1.57-fold and 2.25-fold greater risks of MACE.

Dr van Rosendael said: “In this study, the elevated risk for women versus men was especially observed in postmenopausal women with the highest Leiden CCTA score. This could be partly because the inner diameter of coronary arteries is smaller in women, meaning that the same amount of plaque could have a larger impact on blood flow. Our findings link the known acceleration of atherosclerosis development after menopause with a significant increase in relative risk for women compared to men, despite a similar burden of atherosclerotic disease. This may have implications for the intensity of medical treatment.”

Source: European Society of Cardiology

Study Reveals How Androgen Receptor Functions are Affected by Mutations

Testosterone molecule
Model of a testosterone molecule. Source: Wikimedia CC0

The androgen receptor is a key transcriptional factor for proper sex development, especially in males and the physiological balance of all the tissues that express this receptor. The androgen receptor is involved in several pathologies and syndromes, such as spinal and bulbar muscular atrophy or androgen insensitivity syndrome, for which there is no specific treatment. Regarded as the main initial and progression factor in prostate cancer, this receptor has been the main therapeutic target for the treatment against this disease for decades.

Now, a study published in Science Advances describes the structural and functional effects of mutations on the androgen receptor, as well as how these changes lead to the development of prostate cancer.

Point mutations in the androgen receptor

The human androgen receptor is a key protein in the development and functioning of the prostate in response to male hormones, such as testosterone. Point mutations in the androgen receptor – specifically, one amino acid swapped for another – are one of the main mechanisms than can lead to structural and functional alterations in the receptor, which result in the development of diseases.

The results of the University of Barcelona-led study show that the analysed mutations affect several functional regions of the union domain of the androgen receptor to testosterone. In particular, these are mutations that alter a region of the receptor which is the target for posttranscriptional modifications (that is, modifications in the protein once this is produced).

This type of chemical alterations affect specific amino acids of the androgen receptor and are executed by regulating proteins which are critical for the proper functioning of the receptor. If this receptor’s regulation pathway is altered, such as the case of the presence of mutations described by the team, its function is deregulated and it can be dysfunctional and cause pathologies.

“In our study, we experimentally checked that these mutations deregulate a specific mutation, known as arginine methylation, which is one of the posttranscriptional modifications, due to the structural changes these alterations produce in a functional area of the receptor. Also, we could observe that the deregulation of the androgen receptor methylation involves relevant changes in its function within the cell,” the team concludes.

Source: University of Barcelona