Alterations of Bone Density, Microstructure, and Strength of the Distal Radius in Male Patients With Rheumatoid Arthritis: A Case-Control Study With HR-pQCT

Abstract

In this cross-sectional study, we investigated volumetric bone mineral density (vBMD), bone microstructure, and biomechanical competence of the distal radius in male patients with rheumatoid arthritis (RA). The study cohort comprised 50 male RA patients of average age of 61.1 years and 50 age-matched healthy males. Areal BMD (aBMD) of the hip, lumbar spine, and distal radius was measured by dual-energy X-ray absorptiometry. High-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius provided measures of cortical and trabecular vBMD, microstructure, and biomechanical indices. aBMD of the hip but not the lumbar spine or ultradistal radius was significantly lower in RA patients than controls after adjustment for body weight. Total, cortical, and trabecular vBMD at the distal radius were, on average, -3.9% to -23.2% significantly lower in RA patients, and these differences were not affected by adjustment for body weight, testosterone level, or aBMD at the ultradistal radius. Trabecular microstructure indices were, on average, -8.1% (trabecular number) to 28.7% (trabecular network inhomogeneity) significantly inferior, whereas cortical pore volume and cortical porosity index were, on average, 80.3% and 63.9%, respectively, significantly higher in RA patients. RA patients also had significantly lower whole-bone stiffness, modulus, and failure load, with lower and more unevenly distributed cortical and trabecular stress. Density and microstructure indices significantly correlated with disease activity, severity, and levels of pro-inflammatory cytokines (interleukin [IL] 12p70, tumor necrosis factor, IL-6 and IL-1b). Ten RA patients had focal periosteal bone apposition most prominent at the ulnovolar aspect of the distal radius. These patients had shorter disease duration and significantly higher cortical porosity. In conclusion, HR-pQCT reveals significant alterations of bone density, microstructure, and strength of the distal radius in male RA patients and provides new insight into the microstructural basis of bone fragility accompanying chronic inflammation.

Repair of Bone Erosion in Rheumatoid Arthritis by Denosumab: A High‐Resolution Peripheral Quantitative Computed Tomography Study

“…We have reported alterations in the density and microstructure of the cortical bone of patients with RA . Rossini et al had also observed that low BMD at the cortical site was significantly associated with the presence of bone erosions .…”

Denosumab, cortical bone and bone erosions in rheumatoid arthritis

“…On the other side, from the bone point of view, we previously observed that low bone mineral density (BMD) at the cortical site was significantly associated with the presence of bone erosions,8 and recently Zhu and colleagues reported alterations in the density and microstructure of the cortical bone of patients with RA, providing new insight into the microstructural basis of bone involvement in RA 9. In particular, in patients with anticitrullinated protein antibodies, cortical thinning might be present even before the clinical onset of RA and it seems strictly related with the risk of bone erosions 10…”

Long-Term Effects of Severe Burn Injury on Bone Turnover and Microarchitecture

“…Male patients with rheumatoid arthritis as another representative of a pro‐inflammatory disease suffer from altered trabecular microstructure, increased cortical porosity, and cortical pore volume . In our study population, these cortical indices measured at the radius and later at the tibia increased over time, whereas no differences were observed in the control population.…”