Cortical thinning and progressive cortical porosity in female patients with systemic lupus erythematosus on long-term glucocorticoids: a 2-year case-control study.

UNLABELLED: In this study, we characterized longitudinal changes of volumetric bone mineral density and cortical and trabecular microstructure at the distal radius using HR-pQCT in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids. Cortical thinning and increased cortical porosity are the major features of longitudinal microstructural deterioration in SLE patients. INTRODUCTION: The study aims to characterize longitudinal changes of volumetric bone mineral density (vBMD) and bone microstructure at distal radius in female systemic lupus erythematosus (SLE) patients on long-term glucocorticoids. METHODS: This 2-year case-control study consisted of 166 premenopausal subjects (75 SLE patients and 91 controls) and 79 postmenopausal subjects (44 SLE patients and 35 controls). We obtained areal BMD (aBMD) by dual-energy X-ray absorptiometry at multiple skeletal sites and indices of vBMD and microstructure at distal radius by high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline, 12 and 24 months. RESULTS: In either premenopausal or postmenopausal subjects, changes in aBMD did not differ between patients and controls except that decrease in aBMD at total hip at 24 months in premenopausal patients was significantly higher. In premenopausal subjects, decrease in cortical area (-0.51 vs. -0.06 %, p = 0.039) and thickness (-0.63 vs. 0.02 %, p = 0.031) and increase in cortical porosity (21.7 vs. 7.16 %, p = 0.030) over study period were significantly larger in patients after adjustment of age and body mass index. Decreased in trabecular vBMD was significantly less (-0.63 vs. -2.32 %, p = 0.001) with trabecular microstructure better maintained in patients. In postmenopausal subjects, decrease in cortical vBMD (-2.66 vs. -1.56 %, p = 0.039) and increase in cortical porosity (41.6 vs. 16.3 %, p = 0.021) were significantly higher in patients, and there was no group-wise difference in change of trabecular microstructure. CONCLUSION: Longitudinal microstructural deterioration in SLE is characterized by cortical thinning and increased cortical porosity. Cortical bone is an important source of bone loss in SLE patients on glucocorticoids.

Age-related differences in volumetric bone mineral density, microarchitecture, and bone strength of distal radius and tibia in Chinese women: a high-resolution pQCT reference database study.

UNLABELLED: In a cohort of 393 Chinese women, by using high-resolution peripheral quantitative computed tomography (HR-pQCT), we found that significant cortical bone loss occurred after midlife. Prominent increase in cortical porosity began at the fifth decade but reached a plateau before the sixth decade. Trabecular bone loss was already evident in young adulthood and continued throughout life. INTRODUCTION: This study aimed to investigate age-related differences in volumetric bone mineral density (vBMD), microarchitecture, and estimated bone strength at peripheral skeleton in Chinese female population. METHODS: In a cross-sectional cohort of 393 Chinese women aged 20-90 years, we obtained vBMD, microarchtecture, and micro-finite element-derived bone strength at distal radius and tibia using HR-pQCT. RESULTS: The largest predictive age-related difference was found for cortical porosity (Ct.Po) which showed over four-fold and two-fold differences at distal radius and tibia, respectively, over the adulthood. At both sites, cortical bone area, vBMD, and thickness showed significant quadratic association with age with significant decrease beginning after midlife. Change of Ct.Po became more prominent between age of 50 and 57 (0.26 %/year at distal radius, 0.54 %/year at distal tibia, both p ≤ 0.001) but thereafter, reached a plateau (0.015 and 0.028 %/year, both p > 0.05). In contrast, trabecular vBMD and microarchitecture showed linear association with age with significant deterioration observed throughout adulthood. Estimated age of peak was around age of 20 for trabecular vBMD and microarchitecture and Ct.Po and age of 40 for cortical vBMD and microarchitecture. Estimated stiffness and failure load peaked at mid-30s at the distal radius and at age 20 at distal tibia. CONCLUSIONS: Age-related differences in vBMD and microarchitecture in Chinese women differed by bone compartments. Significant cortical bone loss occurred after midlife. Prominent increase in Ct.Po began at the fifth decade but appeared to be arrested before the sixth decade. Loss of trabecular bone was already evident in young adulthood and continued throughout life.

Density, structure, and strength of the distal radius in patients with psoriatic arthritis: the role of inflammation and cardiovascular risk factors.

UNLABELLED: We investigated the densitometric and microstructural features of the distal radius in psoriatic arthritis (PsA) patients using high-resolution peripheral quantitative computed tomography. PsA patients have unique bone microstructural deficits, manifested as lower cortical bone density and higher cortical porosity, which are associated with a propensity to bone fragility. INTRODUCTION: The aim of this study was to investigate the densitometric, geometric, microstructural, and biomechanical features of the distal radius in psoriatic arthritis (PsA) patients. METHODS: This study cohort consisted of 53 PsA patients (24 males and 29 females), with an average age of 53.1 years and 53 gender- and age-matched controls. Areal bone mineral density (aBMD) of the hip, lumbar spine, and ultradistal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) was performed at the distal radius to obtain measures of volumetric BMD (vBMD), microstructure, and derived biomechanical indices. RESULTS: There were no significant between-group differences in aBMD at the femoral neck, total hip, and ultradistal radius, while aBMD at the lumbar spine was significantly higher in patients. The only indices indicating compromised bone quality in PsA patients were related to cortical bone quality. Cortical vBMD were -3.8% significantly lower, while cortical pore volume, porosity index, and pore diameter were 108, 79.5, and 8.6%, respectively, significantly higher in patients. Cortical stress was marginally lower (-1.3%, p = 0.077) in patients with stress significantly more unevenly distributed (4.9%, p = 0.035). Endocortical perimeter and cortical pore volume were significantly higher in patients with vertebral fracture. Deficits in cortical bone quality were associated with indices of disease activity/severity and were more prominent in patients with type 2 diabetes mellitus or hypertension. CONCLUSIONS: There is an intertwined relationship between chronic inflammation, cardiovascular risk factors, and bone loss in PsA. PsA patients seem to have unique bone microstructural deficits which are associated with a propensity to bone fragility.