The impact of glucocorticoid therapy on trabecular bone score in older women.

Abstract

We propose that trabecular bone score could be a useful tool for the study of glucocorticoid-associated bone effects. Trabecular bone score alone and lumbar spine bone mineral density (BMD) used in combination with trabecular bone score, but not lumbar spine BMD alone was able to discriminate between glucocorticoid-treated and glucocorticoid-naïve women. Glucocorticoids result in rapid bone loss and an increase in fracture risk that cannot be fully explained by changes in BMD. Trabecular bone score (TBS) correlates with three-dimensional bone micro-architectural parameters and can be derived from grey-level variations within dual energy X-ray absorptiometry (DXA) scans. We propose that TBS could be a useful tool for the study of glucocorticoid-associated bone effects. We assessed the ability of lumbar spine BMD (LS-BMD), TBS, and LS-BMD with TBS (LS-BMD + TBS) to discriminate between healthy women and (i) glucocorticoid-treated women, and (ii) glucocorticoid-naïve women with recent fractures. Older women (n = 484, ages 55-79 years) who had (i) taken prednisolone ≥5 mg/day for >3 months (n = 64), (ii) sustained a recent fracture of the distal forearm (n = 46), proximal humerus (n = 37), vertebra (n = 30) or proximal femur (n = 28), or (iii) were healthy population-based women (n = 279) were recruited. LS-BMD was measured by DXA and TBS values were derived. Compared to healthy, population-based women, women with recent fractures had lower LS-BMD (-0.34 to -1.38) and TBS (-0.38 to -1.04) Z-scores. Glucocorticoid-treated women had lower TBS Z-scores than glucocorticoid-naïve women (-0.80 versus 0) but their LS-BMD Z-scores did not differ (-0.13 versus 0). TBS alone (area under the receiver operating characteristic curve (AUC) = 0.721) and LS-BMD + TBS (AUC = 0.721), but not LS-BMD alone (AUC = 0.572) was able to discriminate between glucocorticoid-treated and glucocorticoid-naïve women. TBS provides additional information regarding glucocorticoid-associated alterations in bone quality. We conclude that TBS may be a useful tool for the further study of glucocorticoid-induced osteoporosis.