Inhalers and other steroids linked to changes in the brain
<p dir="ltr">If you’ve been diagnosed with asthma, Chronic Obstructive Pulmonary Disorder (COPD), ezcema or even Crohn’s disease, you’ve likely been prescribed some form of medical steroid to treat it.</p>
<p dir="ltr">However, Dutch scientists are calling for more awareness about potential side effects of using medical steroids, as well as research into alternative treatment options, after they found a link between using these medications and changes in the brain structure and volume.</p>
<p dir="ltr">Glucocorticoids, a class of synthetic steroids found in inhalers and other medicines, fight inflammation in the body, making them highly effective for treating autoimmune diseases, where your body triggers inflammation by mistake and results in your immune system attacking healthy cells as if they were viruses or bacteria. </p>
<p dir="ltr">This immunoprotective quality has made them one of the most frequently prescribed drugs globally.</p>
<p dir="ltr">But, both systemic and inhaled steroid use is associated with abnormalities in brain structure and shrinkage of particular areas, according to previous research.</p>
<p dir="ltr">With this research focusing on small groups of people with specific conditions, a team of Dutch researchers decided to investigate whether these side effects were seen in the broader population, with their findings published in the journal <em><a href="https://doi.org/10.1136/bmjopen-2022-062446" target="_blank" rel="noopener">BMJ Open</a></em>.</p>
<p dir="ltr">Using data from the UK Biobank - a database of genetic and health information from half a million people available to researchers across the world - the team looked to see whether there were differences in the brains of users and non-users of glucocorticoids.</p>
<p dir="ltr">After comparing the brain scans of 222 people who use systemic steroids, 557 using inhaled steroids, and 24,106 people who didn’t use either, they found that use of medical steroids was linked to less intact white brain matter in comparison to scans of non-users.</p>
<p dir="ltr">The white matter in our brains is made up of bundles of nerve fibres covered in a fatty substance called myelin, which gives these areas their white colour. White matter is part of the central nervous system, helping to connect different areas of grey matter to each other and send messages between them. These parts of the brain affect how we learn and how our brains function.</p>
<p dir="ltr">Participants in the study also filled out a questionnaire to assess aspects of their mood over the previous fortnight, as the team wanted to know if steroid use was also linked to changes in processing speed or emotional responses.</p>
<p dir="ltr">They found that systemic use of steroids was associated with a larger caudate - a C-shaped structure in the brain that is involved in associative and procedural learning, working memory, speaking in multiple languages, cognition and emotional processing.</p>
<p dir="ltr">Meanwhile, the use of inhaled steroids was linked to a smaller amygdala, another structure in the brain made of grey matter that is involved in processing emotions, particularly for strong emotions such as fear.</p>
<p dir="ltr">From the questionnaire, the team found systemic steroid users performed worse than non-users when it came to the test measuring processing speed, and that they reported significantly more symptoms of depression, apathy, restlessness, fatigue and lethargy.</p>
<p dir="ltr">Inhaled steroid users also reported more tiredness and lethargy, but to a lesser degree than systemic users.</p>
<p dir="ltr">But, the researchers stress that their findings don’t necessarily mean that medical steroids cause the changes seen in the brain.</p>
<p dir="ltr">“Although a causal relation between glucocorticoid use and changes in the brain is likely based on the present and previous studies, the cross-sectional nature of this study does not allow for formal conclusions on causality,” they caution.</p>
<p dir="ltr">Instead, they say the relationship may explain some of the side effects associated with long-term use of the medications, including anxiety, depression, mania and delirium.</p>
<p dir="ltr">“While it remains unclear whether the observed effect sizes have clinical consequences for the population of glucocorticoid users as a whole, these findings are remarkable given the common neuropsychiatric side effects of synthetic glucocorticoids,” the researchers write.</p>
<p dir="ltr">They conclude that widespread reduction in the integrity of white matter in the brain is associated with both systemic and inhaled steroid use, and argue that this could be an underlying contributor to neuropsychiatric side effects that patients using these steroids can experience.</p>
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<p dir="ltr">Given the widespread use of medical steroids, they add that it’s important for doctors and patients to know about the possible effects they can have on the brain and that more research should be done into alternative options for treatment.</p>
<p dir="ltr"><em>Image: Getty Images</em></p>
