Severe asthma and high doses of corticosteroid adversely impact trabecular bone score more than bone mineral density

Background: In asthmatic patients, treatment with corticosteroids, in addition to conventional risk factors for osteoporosis, may lead to bone loss. Trabecular bone score (TBS) is a new, indirect parameter of bone quality. Studies have yet to evaluate TBS in asthmatic patients in relation to disease severity and corticosteroid use. Objective: This study aimed to evaluate TBS in asthmatics in comparison to propensity score-matched controls and to investigate correlations between TBS and cumulative systemic and inhaled corticosteroid doses 1 year prior to bone mineral density (BMD) measurement in patients with asthma. Methods: In total, 627 patients with asthma and the same number of non-asthmatic controls matched for gender and age were included in this retrospective cohort study. TBS was calculated in the lumbar region, based on two dimensional projections of dual-energy X-ray absorptiometry. Results: Patients with severe asthma exhibited lower vertebral TBS values (1.33±0.11) than those with non-severe asthma (1.37±0.10, P=0.004), with non-active asthma (1.38±0.10, P 0.05). A TBS of 1.42 was determined as a cut-off for osteoporosis. TBS was significantly associated with cumulative systemic and inhaled corticosteroid doses, as well as lung function and airway hyper-responsiveness. Conclusion: TBS can be used as an early indicator of altered bone quality stemming from glucocorticoid therapy or, possibly, more severe asthma.