The use of steroid inhalers increases the risk of hard-to-treat bacterial infection among older people, a new study published in the European Respiratory Journal suggested. While steroid inhalers are used to help manage the symptoms of asthma and/or chronic obstructive pulmonary disease (COPD), researchers from theEuropean Respiratory Society found that they also make users more susceptible to lung infections caused by nontuberculous mycobacteria.
For their study, the researchers pored through linked laboratory and health administrative databases in Canada to look for cases of adults aged 66 or older who had been prescribed medication for obstructive lung disease.
They found 417,494 older adults who fit their exact specifications. Of those patients, the researchers uncovered 2,966 people who had been diagnosed with nontuberculous mycobacterial pulmonary disease and 327 who had been diagnosed with tuberculosis.
From here, the researchers went on to find out whether these patients used steroid inhalers, what type of steroid inhalers they took, and how frequently they used their steroid inhalers. Patients who were using steroid inhalers were twice as likely to be diagnosed with nontuberculous mycobacterial lung disease, the researchers discovered. Prolonged steroid inhaler use was associated with increased risk as well. Moreover, they noted that one particular type of steroid, fluticasone, was especially risky.
“These infections are not particularly common but they are chronic and difficult to treat, and are associated with an increased risk of death. Treatment typically requires at least three antibiotics given for longer than a year and this can still fail to tackle the infection,” said lead researcher Dr. Sarah K. Brode.
Along with her colleagues, Dr. Brode intends on continuing their efforts with this group of patients by investigating possible treatments against nontuberculous mycobacterial lung disease.
What is nontuberculous mycobacterial lung disease?
Nontuberculous mycobacterial lung disease is the general term for a group of disorders caused by exposure to mycobacteria, which are rod-shaped bacterial germs usually found in the environment. The most common type of mycobacteria cause tuberculosis and leprosy, with “nontuberculous” being used to differentiate between disorders.
The symptoms and severity of nontuberculous mycobacterial lung disease varies from person to person, though the exact mechanism behind this remains unknown. Chronic lung infection occurs in 94 percent of individuals diagnosed with nontuberculous mycobacterial lung disease. Individuals with this disorder are known to display symptoms typically synonymous with other respiratory infections, such as excessive mucus production, shortness of breath, coughing up of blood, and unintended weight loss.
Mycobacterial exposure only causes certain people to become sick, and the underlying reason has yet to be determined. One theory posits that immune system deficiencies make particular individuals more likely to develop nontuberculous mycobacterial lung disease.
The connection between steroid inhalers and nontuberculous mycobacterial lung disease
This could very well be the case with the patients covered in this study. When high doses of inhaled steroids enter the body, small amounts of the medicine is absorbed into the immune system and suppress it, which can then cause this particular system to function poorer than usual. Though this effect is often concentrated in the lungs, as this is how inhaled steroids help patients control the symptoms of asthma. Inhaled steroids mimic adrenal gland hormones that help suppress inflammation, and end up suppressing the immune system in the process.
Currently, treating nontuberculous mycobacterial lung disease is a momentous challenge as the antiobiotic drugs prescribed in the drug regimen are expensive, often poorly tolerated by the patients, and need the patients to remain on these medications for long periods of time.