Background: Whether the use of inhaled corticosteroids (ICSs) in patients with COPD can protect from osteoporosis remains undetermined. The aim of this study is to assess the incidence of osteoporosis in patients with COPD with ICS use and without.
Patients and methods: This is a retrospective cohort and population-based study in which we extracted newly diagnosed female patients with COPD between 1997 and 2009 from Taiwan's National Health Insurance (TNHI) database between 1996 and 2011 (International Classification of Diseases, Ninth Revision - Clinical Modification [ICD-9-CM] 491, 492, 496). The patients with COPD were defined by the presence of two or more diagnostic codes for COPD within 12 months on either inpatient or outpatient service claims submitted to TNHI. Patients were excluded if they were younger than 40 years or if osteoporosis had been diagnosed prior to the diagnosis of COPD and cases of asthma (ICD-9 CM code 493.X) before the index date. These enrolled patients were followed up till 2011, and the incidence of osteoporosis was determined. The Cox proportional hazards regression model was also used to estimate hazard ratios (HRs) for incidences of lung cancer.
Results: Totally, 10,723 patients with COPD, including ICS users (n=812) and nonusers (n=9,911), were enrolled. The incidence rate of osteoporosis per 100,000 person years is 4,395 in nonusers and 2,709 in ICS users (HR: 0.73, 95% confidence interval [CI]: 0.63-084). The higher ICS dose is associated with lower risk of osteoporosis (0 mg to ≤20 mg, HR: 0.84, 95% CI: 0.69-1.04; >20 mg to ≤60 mg, HR: 0.78, 95% CI: 0.59-1.04; and >60 mg, HR: 0.72, 95% CI: 0.55-0.96; P for trend =0.0023) after adjusting for age, income, and medications. The cumulative osteoporosis probability significantly decreased among the ICS users when compared with the nonusers (P<0.001).
Conclusion: Female patients with COPD using ICS have a dose-response protective effect for osteoporosis.
Keywords: COPD; inhaled corticosteroids; osteoporosis.