Rats!

Posted by Lynn Bronikowski  

Study: Marijuana use associated with increased risk of stroke!  Using marijuana raises the risk of stroke and heart failure even after accounting for demographic factors, other health conditions and lifestyle risk factors such as smoking and alcohol use, according to new national research.

Coming at a time when marijuana, medically known as cannabis, is on track to become legal for medical or recreational use in more than half of U.S. states, this study sheds new light on how the drug affects cardiovascular health. While previous marijuana research has focused mostly on pulmonary and psychiatric complications, the new study is one of only a handful to investigate cardiovascular outcomes.

“Like all other drugs, whether they’re prescribed or not prescribed, we want to know the effects and side effects of this drug,” said Aditi Kalla, MD, Cardiology Fellow at the Einstein Medical Center in Philadelphia and the study’s lead author. “It’s important for physicians to know these effects so we can better educate patients, such as those who are inquiring about the safety of cannabis or even asking for a prescription for cannabis.”

The study drew data from the Nationwide Inpatient Sample, which includes the health records of patients admitted at more than 1,000 hospitals comprising about 20 percent of U.S. medical centers. Researchers extracted records from young and middle-aged patients—age 18-55 years— who were discharged from hospitals in 2009 and 2010, when marijuana use was illegal in most states.

Marijuana use was diagnosed in about 1.5 percent (316,000) of more than 20 million health records included in the analysis. Comparing cardiovascular disease rates in these patients to disease rates in patients not reporting marijuana use, researchers found marijuana use was associated with a significantly increased risk for stroke, heart failure, coronary artery disease and sudden cardiac death.

Marijuana use was also linked with a variety of factors known to increase cardiovascular risk, such as obesity, high blood pressure, smoking and alcohol use. After researchers adjusted the analysis to account for these factors, marijuana use was independently associated with a 26 percent increase in the risk of stroke and a 10 percent increase in the risk of developing heart failure.

“Even when we corrected for known risk factors, we still found a higher rate of both stroke and heart failure in these patients, so that leads us to believe that there is something else going on besides just obesity or diet-related cardiovascular side effects,” Kalla said. “More research will be needed to understand the pathophysiology behind this effect.”

Research in cell cultures shows that heart muscle cells have cannabis receptors relevant to contractility, or squeezing ability, suggesting that those receptors might be one mechanism through which marijuana use could affect the cardiovascular system. It is possible that other compounds could be developed to counteract that mechanism and reduce cardiovascular risk, Kalla said.

Because the study was based on hospital discharge records, the findings may not be reflective of the general population. The study was also limited by the researchers’ inability to account for quantity or frequency of marijuana use, purpose of use (recreational or medical), or delivery mechanism (smoking or ingestion).

Kalla suggested that the growing trend toward legalization of marijuana could mean that patients and doctors will become more comfortable speaking openly about marijuana use, which could allow for better data collection and further insights into the drug’s effects and side effects.

The research was scheduled for presentation at the American College of Cardiology’s 66th Annual Scientific Session.

 

Adults With Heart Defects May Face Higher Risk of Stroke

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Posted by Robert Preidt, HealthDay Reporter

Adults who were born with heart defects are at increased risk for stroke, a new study finds.

“We knew there was a connection between heart failure and stroke in patients with heart defects, but we were surprised to discover it was the strongest predictor,” said senior study author Dr. Ariane Marelli, a professor of medicine at McGill University in Montreal.

However, the study did not prove that heart defects cause stroke.

For the study, researchers looked at stroke rates among more than 29,000 adults born with heart defects, and compared them with rates among people in the general population of the province of Quebec, Canada.shutterstock_116455033 copy

Those with heart defects were nine to 12 times more likely to suffer an ischemic stroke (blocked blood flow to the brain) before age 55. In addition, they were two to four times more likely to have this type of stroke between the ages of 55 and 64, the investigators found.

The strongest predictors of ischemic strokes in adults with heart defects were heart failure, diabetes and recent heart attacks, the study authors said.

In addition, adults born with heart defects were five to six times more likely to have a bleeding (“hemorrhagic”) stroke before age 55, and two to three times more likely to have this type of stroke between the ages of 55 and 64.

Nearly 9 percent of men and 7 percent of women born with heart defects had at least one stroke before age 65, according to the study published online Nov. 23 in the journal Circulation.

“Our study also suggests that other well-known risk factors for stroke — such as irregular heartbeat and high blood pressure — may be under-detected in patients born with a heart defect,” study first author Dr. Jonas Lanz, a research fellow at McGill, said in a journal news release.

The findings show the need for adults born with heart defects to make regular visits to a cardiologist, to reduce their risk of stroke, Marelli said.

These patients, along with their family and friends, should also learn the signs of stroke and know how to get professional medical help quickly if a stroke is suspected, she added.
Every year, nearly 129,000 Americans die of stroke, which is the nation’s fifth leading cause of death.

SOURCE: Circulation, news release, Nov. 23, 2015

Recovery from stroke may be achieved?

These brain cells grew new connections after exposure to GDF10.  Image credit: UCLA

Written by Catharine Paddock PhD

A study led by researchers from the University of California-Los Angeles (UCLA) and published in Nature Neurologyidentifies a molecule called growth differentiation factor 10 (GDF10) that signals brain tissue to form new connections following a stroke.

The senior author of the study is neurologist and neuroscientist S. Thomas Carmichael, professor and vice chair for research and programs in UCLA’s department of neurology. He and his colleagues hope their findings will lead to new treatments to help patients recover brain function following a stroke.

Prof. Carmichael says their study is the first to identify that GDF10 has a function in the adult brain. He explains the importance of the finding:

“The brain has a limited capacity for recovery after stroke. Most stroke patients get better after their initial stroke, but few fully recover. If the signals that lead to this limited recovery after stroke can be identified and turned into a treatment, then it might be possible to enhance brain repair after stroke.”

The researchers started by searching for molecules that are prevalent in the brain following a stroke and listing all the genes that are switched on or off (they had already identified them in earlier work).

This was how GDF10 emerged as a possible trigger for brain repair, so the team investigated it more closely by looking at how it behaves in brain cells in the Petri dish and in animals.

GDF10 encourages brain cells to make new connections

The researchers found that GDF10 appears to encourage brain cells to make new connections. Prof. Carmichael comments:

“We found that GDF10 induces new connections to form in the brain after stroke, and that this mediates the recovery of the ability to control bodily movement.”

Fast facts about stroke

  • Stroke is the fifth leading cause of death for Americans
  • About 87% of all strokes are ischemic strokes, when blood flow to the brain is blocked
  • Although the risk of stroke increases with age, it can strike at any age.

Find out more about stroke

After identifying the signaling systems that control the process of making new connections, the team then pinpointed the molecules that GDF10 switches on and off in brain cells after a stroke.

They compared what happens to the RNA in these cells to what happens to the RNA in similar cells during brain development and learning, and to the RNA in brain cells of people with other types of disease.

RNA (ribonucleic acid) is an essential molecule that helps to pass the genetic information held in DNA onto proteins. It is also important for protein synthesis and gene regulation.

The researchers found that GDF10 controls a unique group of molecules that help brain tissue recover following a stroke.

They suggest this process of brain tissue repair following a stroke is unique and not simply a reactivation of molecules involved in brain development.

The researchers then explored the effect of GDF10 on brain areas linked to limb control. They mapped brain connections in this area in animals (rats and mice) that were given GDF10 following a stroke, in animals that suffered stroke but did not receive GDF10, in healthy animals and in animals that were given less GDF10 following a stroke.

Prof. Carmichael describes what they found:

“The results indicated that GDF10 normally is responsible for the very limited process of the formation of new connections after stroke. Delivering more GDF10 markedly enhances the formation of new connections and does so mostly in a specific brain circuit. The formation of connections in this circuit with GDF10 administration significantly enhanced recovery of limb control after stroke.”

He and his colleagues are now looking for a small molecule that could trigger GDF10 signaling and possibly lead to a drug to improve recovery after stroke.

Meanwhile, Medical News Today recently learned of new research that shows  high-stress jobs can lead to stroke, especially in women. Reporting in the journal Neurology, researchers from Southern Medical University in Guangzhou, China, defined high-stress jobs as being occupations where demands are high and control is low – such as that experienced by waitresses and nursing aides.

How Stroke Affects Cognition Over Time


                                                   Provided by Shutterstock

Posted by Lisa O’Neill Hill

A new study has found that people who have survived a stroke may continue to have challenges with their thinking years after the brain attack, and that those challenges may get worse. The study is one of the first to follow cognitive decline in stroke survivors over a long period of time.

The study, published in JAMA, was conducted over the course of six years, and suggests that stroke survivors may need to be monitored for cognitive impairment long after their strokes.

Unlike previous studies, which have suggested that cognitive decline doesn’t speed up after a stroke unless another one occurs, the recent findings suggest the opposite.

New Long-term Expectations

“The information is useful as education for patients and their caregivers to understand what might be expected in the long term after a stroke,” said Richard D. Zorowitz, MD, Attending Physician, Outpatient Services, MedStar National Rehabilitation Network in Washington, D.C.  “This may allow patients, their caregivers, and their physicians, to anticipate potential issues that may arise in the future and plan appropriately for them. In addition, there may be medications, such as stimulants like Ritalin, or dementia drugs, that may slow cognitive decline over time.”

The study included 23,572 people from the United States who were 45 or older. They did not have cognitive challenges when they entered the study. Out of the group, 515 people had strokes—470 ischemic, 43 hemorrhagic and two of unknown type. Researchers said the people who’d had strokes were more likely to have health problems such as higher blood pressure and diabetes, be older, and be male.

The stroke survivors had a “significantly faster” rate of cognitive impairment compared to the people who hadn’t had strokes.

Specific Areas of Cognitive Decline

Stroke was associated with a decline in verbal memory, new learning, and global cognition. Compared to the non-stroke group, stroke survivors had more challenges with global cognition and things like reasoning and problem solving, but not with new learning and verbal memory.

The findings may affect the future of patient care, research, and health care policy.

Survivors, now monitored before they’re discharged from the hospital and in rehab settings, should be checked for growing cognitive impairment years after their strokes. Cognitive decline greatly increases the risk of death, depression, dementia, and functional decline, the study said.