Lumbar Spine Trabecular Bone Score (TBS) Reflects Diminished Bone Quality in Patients With Diabetes Mellitus and Oral Glucocorticoid Therapy

Abstract

Trabecular bone score (TBS) is a texture parameter that measures the grayscale variation within dual-energy X-ray absorptiometry (DXA) images, and has been shown to significantly correlate with the 3-dimensional bone microarchitecture. The objective of this study was to determine whether TBS is a better clinical tool than traditionally used bone mineral density (BMD) to detect the skeletal deterioration seen in patients with diabetes (DM), patients undergoing oral glucocorticoid (GC) therapy, and patients who are both diabetic and taking steroids (GC + DM). We performed retrospective, cross-sectional study using DXA images of patients who visited UTHealth Department of Internal Medicine DXA clinic in Houston, TX, from May 30, 2014 to May 30, 2016. A total of 477 men and women, who were 55 years or older, were included in the study. Lumbar spine (LS) BMD and TBS were collected. Electronic medical records were reviewed to collect clinical information for each patient. When both men and women were analyzed as a single group, LS-BMD was significantly higher in the diabetic group than in the control group (1.14 vs 1.10, p = 0.038), whereas mean TBS of L1-L4 was significantly lower in the diabetic group (1.21 vs 1.26, p = 0.004). LS-TBS was also significantly lower in diabetic women than in nondiabetic women (1.20 vs 1.26, p = 0.002). Receiver operating characteristic curves and areas under the curve indicated that LS-TBS provided better ability than LS-BMD to discriminate between control subjects and those in the DM, GC, or GC + DM groups (areas under the curve between 0.645 and 0.697, p < 0.010 for all). LS-TBS is a BMD-independent parameter that is capable of capturing a larger portion of bone quality deterioration undetected by BMD alone in patients with DM and undergoing oral GC therapy.

Keywords: Bone mineral density; diabetes mellitus; glucocorticoid; trabecular bone score.