Dose-dependent association between inhaled corticosteroid use and risk of obesity and metabolic syndrome in asthma.

Background: Inhaled corticosteroids (ICS) are widely prescribed medications. Some studies have reported that ICS may suppress the hypothalamic-pituitary-adrenal axis and induce systemic effects. Objective: To explore the possibility of a dose-dependent association between the long-term use of ICS and the risk of obesity and other markers of metabolic syndrome. Methods: A 5-year retrospective two-arm cohort study explored patients on asthma and not on ICS relative to patients with asthma who were on varying doses of ICS (low, medium, and high) and attributes such as body mass index (BMI) trajectory and prescription of antihypertensive, antidiabetic, and cholesterol-lowering medications. Results: A total of 229 subjects with asthma were in the control cohort, and 215 subjects with asthma were in the ICS cohort. The ICS cohort was subdivided into individuals on low- (n = 88), medium- (n = 107), or high- (n = 20) dose ICS throughout the 5-year study period. For every 1-year increase in time, the BMI in the high-dose ICS group increased at a rate of 0.25 kg/m² when compared with the subjects in the control group after controlling for age and gender. Also, for every 1-year increase in time, the BMI of those on medium-dose ICS increased by 0.06 kg/m² compared with those in the control group after controlling for age and gender. The subjects on ICS also had a statistically increased risk of being prescribed antihypertensive, antidiabetic, and cholesterol-lowering medications. Conclusion: ICS use in the subjects with asthma was associated with a dose-dependent risk of increasing BMI trajectories over time and an increased requirement for antidiabetic and cholesterol-lowering medications. One possible conclusion from this study is that long-term medium- and high-dose ICS have the potential to induce systemic effects.