Patients suffering from chronic obstructive pulmonary disorder (COPD) who take inhaled corticosteroids are at increased risk of developing type 2 diabetes, and more so with higher doses, according to a new study published in The American Journal of Medicine. The study found that the risk for asthmatics was much less significant.

“These medications are very effective in asthma, so the benefits clearly outweigh the risk for asthmatics,” said Samy Suissa, MD, director of the Centre for Clinical Epidemiology at the Jewish General Hospital’s Lady Davis Institute for Medical Research in Montreal. “However, their effectiveness is questionable in COPD, where they are also used in higher doses. This is a very different risk/benefit situation.”

Inhaled corticosteroids are administered in the form of aerosol sprays and micropowders, and include drugs like fluticasone (Flonase®, Advair®), budesonide (Pulmicort®, Rhinocort®) and beclometasone (QVAR®, Beclovent®).

Oral corticosteroids like predinisone have long been known to increase the risk of diabetes, but this is the first time the effect has been observed with the inhaled form.

For the study, the researchers studied a cohort of nearly 400,000 patients treated for COPD or asthma. They determined that inhaled corticosteroids increased the rate of onset of diabetes from 14 people per 1000 to 19 per 1000, or 34%, every year of use. In other words, five additional people for every 1000 users in the study—people who otherwise would not have been affected—developed diabetes from the use of the drug.

“These are not insubstantial numbers. Over a large population the absolute numbers of affected people are significant,” said Suissa. “We recommend that physicians reserve the use of inhaled steroids for the patients who truly benefit from these medications, namely asthmatics, and curb their use in COPD to the few patients for who they are indicated. In all cases, patients using high doses should be assessed for possible hyperglycemia and the lowest effective dose targeted.”

Source: Jewish General Hospital