Trabecular Bone Score Is More Sensitive to Asthma Severity and Glucocorticoid Treatment Than Bone Mineral Density in Asthmatics

Purpose: In asthmatic patients, treatment with corticosteroids, in addition to conventional risk factors for osteoporosis, may lead to bone loss. Trabecular bone score (TBS) is an indirect new parameter of bone quality. 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 sex and age were included in this retrospective cohort study. TBS was calculated in the lumbar region, based on 2 dimensional projections of dual-energy X-ray absorptiometry. Results: Patients with severe asthma exhibited lower vertebral TBS values (1.32 +/- 0.1) than those with non-severe asthma (1.36 +/- 0.1, P = 0.001), with non-active asthma (1.38 +/- 0.1, P < 0.001), and without asthma (1.39 +/- 0.1, P < 0.001). No significant differences in BMD were noted among the study groups. TBS was significantly correlated with cumulative systemic and inhaled corticosteroid doses as well as asthma duration, lung function and airway hyper-responsiveness. A generalized linear model revealed that age, severe asthma, and frequency of oral corticosteroid burst were significant predictors for TBS levels. Conclusions: TBS can be used as an early indicator of altered bone quality stemming from glucocorticoid therapy or, possibly, more severe asthma.