CNN
—
Taking oral or inhaled glucocorticoids, a type of steroid used to curb inflammation in asthma and other autoimmune disorders, may be linked to harmful changes in the brain’s white matter, a new study found.
“This study shows that both systemic and inhaled glucocorticoids are associated with an apparently generalized reduction in white matter integrity,” wrote study author Merel van der Meulen, a postdoctoral student at Leiden University Medical Center. in the Netherlands, in the studio. published Tuesday in the journal BMJ Open.
White matter is the tissue that forms connections between brain cells and the rest of the nervous system. Having less white matter can slow down your brain’s ability to process information, pay attention, and remember. Lower levels of white matter have also been linked to psychiatric problems such as depressionanxiety and irritability.
“This new study is particularly interesting because it shows the extent to which white matter, which is necessary for neurons to connect to each other, is affected by medication use,” said Thomas Ritz, a psychology professor at North Methodist University. Sur, who investigated the impact of steroids on people with asthma. He was not involved in the study.
However, “there is no reason to be alarmed,” said the neuroimmunologist Dr. Avindra Nath, clinical director of the National Institute of Neurological Disorders and Stroke, who was also not involved in the study. Doctors have long known that if you give patients steroids, “the brain shrinks, but when you take the steroids off, it comes back,” Nath said.
Due to brain plasticity, the brain’s ability to reorganize its structure, functions or connections, “these could be temporary effects,” he said. “They don’t necessarily have to be permanent. White matter can repair itself.”
Glucocorticoids are some of the most frequently prescribed anti-inflammatory drugs due to their widespread use in a number of conditions, experts say.
In addition to asthma, both oral and inhaled glucocorticoids can be used to treat allergies, chronic obstructive pulmonary disease (COPD), Crohn’s disease and other types of inflammatory bowel disease, eczema and other skin conditions, lupus, tendonitis, multiple sclerosis, osteoarthritis, and rheumatoid arthritis.
Nevertheless, glucocorticoid inhalers not to be confused with quick-relief inhalers used to stop an asthma attack. Quick-relief inhalers contain nonsteroidal medications that relax the muscles in the lungs, such as albuterol, levalbuterol, and pirbuterol, which can open the airways in minutes. Inhaled corticosteroids do not work in emergencies; they are prescribed for long-term control of inflammatory conditions.
Previous research has linked long-term use of oral glucocorticoids with structural brain abnormalities and shrinkage of certain brain areas, as much as mental health problems such as anxiety, depression, confusion and disorientation. Studies have also shown that people who have lived with asthma have higher rates of cognitive and memory impairment later in life than people without the condition.
But much of the previous research has been small-scale and at times inconclusive, experts say.
The new study used data from the UK Biobank, a large biomedical research center that followed 500,000 UK residents between 2006 and 2010. From that database, the researchers were able to find 222 oral glucocorticoid users and 557 inhaled glucocorticoid users who had no previous diagnosis of any neurological, hormonal or mental health problems.
Those people underwent cognitive and mental health tests and received a diffusion MRI of the brain. The researchers mined that data and compared those cognitive and MRI findings to more than 24,000 people in the database who weren’t using steroids.
“To our knowledge, this is the largest study to date evaluating the association between glucocorticoid use and brain structure, and the first to investigate these associations in inhaled glucocorticoid users,” the study authors wrote.
The study found the greatest amount of white matter damage in people who use oral steroids regularly for long periods of time. The mental processing speed of chronic oral steroid users was lower than that of non-users. People taking oral steroids also had more apathy, depression, fatigue, and restlessness than those not using steroids.
The smallest impact on white matter occurred in people using inhaled steroids, the study found.
That fits with what doctors see in clinical practice, said pulmonologist Dr. Raj Dasgupta, an assistant professor of clinical medicine at the University of Southern California Keck School of Medicine.. He was not involved in the study.
“We don’t see side effects as often with the inhaled form of glucocorticoids,” he said. “And of course the mainstay of therapy for allergies and asthma will always be avoiding triggers and making lifestyle modifications.”
Pulmonologists and rheumatologists are cautious with prescribe the smallest dose of steroids needed to control symptoms, Dasgupta said, because of the myriad of side effects of steroid use that can also affect health, including brain health.
“As a physician, the moment you start a person on these medications, you immediately think, ‘How can I safely and timely remove that person?’ Steroids cause weight gain, and weight gain will always be a risk for developing diabetes and high blood pressure,” Dasgupta said.
“When you give steroids to people with diabetes, their blood sugar level can go up,” he added. “When you take steroids acutely, you could definitely have insomnia and trouble sleeping, and when you take steroids long-term, it puts you at high risk for infections because they are immunosuppressive.”
The new study had limitations. For one thing, it couldn’t determine steroid dosage or track adherence, Ritz said.
“We know that only about 50% of asthma patients take their medications as prescribed, and possible overreporting of intake is also an issue,” Ritz said. “You should take your inhaled corticosteroids, which reduce inflammation locally, as regularly as possible, but at the lowest possible dose that will control your asthma.
“This study gives us another reason to keep doses low,” he added.
Another limitation was that it couldn’t differentiate between people taking steroid tablets and those using infusions, according to the study authors.
“The study mainly confirms what we have known for a long time about asthma control: take as few systemic (oral) corticosteroids as possible, as long as you are not a patient with severe asthma. Stick to inhaled steroids and discuss with your treating physician plans to reduce drug regimens during good times,” Ritz said.
“This is a very well done study,” said Nath. “But the findings call for another study to see how long these effects last and how they can be reversed.”
.
