A new study found that the use of oral or inhaled glucocorticoids, a type of steroid used to reduce inflammation in asthma and other autoimmune conditions, may be associated with detrimental changes in the white matter of the brain.
This study, led by Merel van der Meulen, a postdoctoral fellow at Leiden University Medical Center in the Netherlands, and published Tuesday in the journal BMJ Open, “shows that both systemic and inhaled glucocorticoids are associated with a apparently generalized reduction in white matter integrity.”
Tissue known as “white matter” is what connects brain cells to the rest of the nervous system. The brain’s ability to process information, pay attention, and remember can be decreased by having less white matter. Lower white matter volumes have also been linked to psychiatric conditions such as anxiety, depression, and irritability.
Thomas Ritz, a professor of psychology at Southern Methodist University who has studied the effects of steroids on people with asthma and was not involved in the study, said the new study is especially compelling because it shows how drug use affects white matter. , which are necessary for neurons to connect with each other.
But according to neuroimmunologist Dr. Avindra Nath, clinical director of the National Institute of Neurological Disorders and Stroke, who was also not involved in the study, “there is no reason to be alarmed.” The brain shrinks when patients are given steroids, but returns when the steroids are stopped, doctors have long known, according to Nath.
These “could be temporary effects,” he said, referring to the brain’s ability to restructure its connections, functions and structure. They don’t have to be permanent, necessarily. White matter is capable of self-repair.
Due to their widespread use in a variety of diseases, specialists suggest that glucocorticoids are among the most widely prescribed anti-inflammatory drugs.
Allergies, chronic obstructive pulmonary disease (COPD), Crohn’s disease and other forms of inflammatory bowel disease, eczema and other skin conditions, lupus, tendonitis, multiple sclerosis, osteoarthritis, and rheumatoid arthritis can be treated with oral and inhaled glucocorticoids in addition to treating asthma.
However, quick-relief inhalers used to stop an asthma attack should not be confused with glucocorticoid inhalers. Albuterol, levalbuterol, and pirbuterol are examples of nonsteroidal medications found in quick-relief inhalers that relax the muscles in the lungs and can quickly open the airways. Inhaled corticosteroids are indicated for the long-term treatment of inflammatory diseases; They are ineffective in crises.
Long-term use of oral glucocorticoids has been linked to structural changes in the brain and shrinkage of certain parts of the brain, as well as mental health problems such as anxiety, depression, confusion, and sense of loss. In addition, research has indicated that people with asthma are more likely than people without asthma to experience cognitive and memory decline later in life.
However, many previous studies have been limited in scope and sometimes inconclusive, according to specialists.
The new research used information compiled by the UK BioBank, a huge biomedical research center that monitored the health of 500,000 people living in the UK between 2006 and 2010. From this database, the researchers were able to find 222 people who used oral glucocorticoids and 557 people who used inhaled glucocorticoids but had never been diagnosed with a neurological, hormonal, or mental health disorder.
These individuals had their cognitive and mental health assessed and underwent diffusion MRI of the brain. The researchers pulled this information from the database and compared MRI and cognitive outcomes with those of nearly 24,000 people who did not use steroids.
The researchers pulled this information from the database and compared MRI and cognitive outcomes with those of nearly 24,000 people who did not use steroids.
According to the study authors, this is the largest study to date examining the relationship between glucocorticoid use and brain anatomy. It is also the first to look at these relationships in people using inhaled glucocorticoids.
The study found that those who use oral steroids consistently for long periods of time have the most severe white matter damage. Chronic oral steroid users were rated as slower in terms of mental processing speed than non-users. Additionally, apathy, hopelessness, fatigue, and restlessness were more common among oral steroid users than nonusers.
The study found that steroid inhalation had the slightest effect on white matter.
According to pulmonologist Dr. Raj Dasgupta, an assistant professor of clinical medicine at the University of Southern California Keck School of Medicine, who was not involved in the study, it’s consistent with what medical professionals see in clinical practice.
“We don’t see side effects as often with the inhaled form of glucocorticoids,” he added. “And of course the mainstay of therapy for allergies and asthma will always be avoiding triggers and making lifestyle modifications.”
According to Dasgupta, because of the many adverse effects of steroid use that can also affect health, particularly brain health, pulmonologists and rheumatologists are cautious about prescribing the smallest dose of steroids needed to control symptoms.
“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,” added Dasgupta as aforementioned by CNN.
He continued: “When you give steroids to people with diabetes, their blood sugar level can go up. 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.”
More study required
The new research had limitations. To begin with, Ritz said, he was unable to calculate steroid dosage or monitor adherence.
“We know that only about 50% of patients with asthma take their medications as prescribed, and possible overreporting of intake is also an issue,” Ritz added.
“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 continued.
The inability to distinguish between infusion users and steroid tablet users is another limitation, according to the study authors.
The study results mainly confirm “what we have known for a long time about asthma control: take as little 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 medication regimens during good times,” according to Ritz.
Nath commented: “It is a very well done study. But the findings call for another study to see how long these effects last and how they can be reversed.”
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