Patients with adrenal incidentalomas (AIs) and subclinical hypercortisolism (SH) have increased risk of fracture independent of bone mineral density (BMD) and possibly due to reduced bone quality. The trabecular bone score (TBS) has been proposed as a index of bone microarchitecture. The aim of the study was to investigate TBS in AI. In 102 AI patients, SH was diagnosed in the presence of at least two of the following: (1) urinary free cortisol >70 mg/24 h (193.1 nmol/L); (2) cortisol after 1-mg dexamethasone suppression test (1-mg DST) >3.0 mg/dL (82.8 nmol/L); or (3) adrenocorticotropic hormone (ACTH) <10 pg/mL (<2.2 pmol/L). In patients and in 70 matched controls, BMD was measured at lumbar spine (LS) and femur (neck [FN] and total [FT]) by dual X-ray absorptiometry and TBS was assessed in the region of LS-BMD; BMD and TBS data were reported as Z-scores. In patients, vertebral deformities were assessed by radiograph. Patients with SH (n ¼ 34) had lower LS-BMD (À0.31 AE 1.17), FT-BMD (À0.29 AE 0.91), and TBS (À3.18 AE 1.21) than patients without SH (n ¼ 68, 0.31 AE 1.42, p ¼ 0.03; 0.19 AE 0.97, p ¼ 0.01; À1.70 AE 1.54, p < 0.0001, respectively) and controls (0.42 AE 1.52, p ¼ 0.02; 0.14 AE 0.76, p ¼ 0.02; À1.19 AE 0.99, p < 0.0001, respectively). TBS was inversely correlated with 1-mg DST (b ¼ À0.26, t ¼ À2.79, p ¼ 0.006) regardless of age, LS-BMD, body mass index (BMI), and gender. The presence of fracture was associated with low TBS alone (odds ratio [OR], 4.8; 95% confidence interval [CI], 1.85-12.42, p ¼ 0.001) and with the cluster low TBS plus low LS-BMD (OR, 4.37; 95% CI, 1.71-11.4, p ¼ 0.002), after adjustment for age, BMI, and gender. Low TBS plus low LS-BMD showed a good specificity (79%) for predicting fractures, whereas normal TBS (ie, > À1.5) plus normal LS-BMD high specificity (88.1%) for excluding fractures. Finally, TBS predicted the occurrence of a new fracture in 40 patients followed for 24 months (OR, 11.2; 95%CI, 1.71-71.41, p ¼ 0.012) regardless of LS-BMD, BMI, and age. In SH, bone quality, as measured by TBS, is altered. TBS is useful in detecting AI patients at risk of fractures. ß

Objective: In primary hyperparathyroidism (PHPT), vertebral fractures (VFx) occur regardless of bone mineral density (BMD) and may depend on decreased bone quality. Trabecular bone score (TBS) is a texture measurement acquired during a spinal dual-energy X-ray absorptiometry (DXA). Recently, TBS has been proposed as an index of bone micro-architecture. Design: We studied 92 PHPT patients (74 females, age 62.1G9.7 years) and 98 control subjects. In all patients at baseline, in 20 surgically treated patients and in 10 conservatively treated patients after 24 months, TBS, spinal (lumbar spine (LS)) and femoral (total hip (TH) and femoral neck (FN)) BMD were assessed by DXA and VFx by spinal radiograph. Results: PHPT patients had lower TBS (K2.39G1.8) and higher VFx prevalence (43.5%) than controls (K0.98G1.07 and 8.2% respectively, both P!0.0001). TBS was associated with VFx (odds ratio 1.4, 95% CI 1.1-1.9, PZ0.02), regardless of LS-BMD, age, BMI and gender, and showed a better compromise between sensitivity (75%) and specificity (61.5%) for detecting VFx than LS-BMD, TH-BMD and FN-BMD (31 and 75%, 72 and 44.2%, and 64 and 65% respectively). In surgically treated patients, TBS, LS-BMD, TH-BMD and FN-BMD increased (C47G44.8,C29.2 G34.1,C49.4G48.7 and C30.2G39.3% respectively, all P!0.0001). Among patients treated conservatively, TBS decreased significantly in those (nZ3) with incident VFx (K1.3G0.3) compared with those without (K0.01G0.9, PZ0.048), while BMD changes were not statistically different (LS 0.3G1.2 vs K0.8G0.9 respectively, PZ0.19; TH 0.4G0.8 vs K0.8G1.4 respectively, PZ0.13 and FN 0.4G0.9 vs K0.8G1.4 respectively, PZ0.14). Conclusions: In PHPT, bone quality, as measured by TBS, is reduced and associated with VFx and improves after surgery.