Inhaled corticosteroids and the risk of diabetes among the elderly.

Abstract

There is evidence that large doses of inhaled corticosteroids lead to an increased risk of glaucoma, cataracts and other problems associated with oral corticosteroid use. However, no formal investigation so far has been conducted into the relationship between inhaled corticosteroids and diabetes. Our nested case-control design studied the association between current use of inhaled corticosteroids and the risk of using antidiabetic medications among a cohort of 21 645 elderly subjects. We also investigated the possibility of a dose-response relationship in users of beclomethasone. Data were obtained from the medical and pharmaceutical databases of the Regie de l'assurance maladie du Québec. Within the cohort, we identified 1494 cases and we selected 14 931 controls using density sampling. The unadjusted rate ratio (and 95% confidence interval, CI) for developing diabetes among current users of inhaled corticosteroids was 1.4 (1.2, 1.5). After adjusting for covariates, the rate ratio (95% CI) decreased to 0.9 (0.8, 1.1). The loss of statistical significance was due in large part to adjusting for the current use of oral corticosteroids. We also did not observe a statistically significant increase in risk among users of high-dose beclomethasone compared to nonusers, after adjusting for covariates. Our results do not indicate an increased risk of diabetes among current users of inhaled corticosteroids.