Trabecular Bone Score and Bone Quality in Systemic Lupus Erythematosus Patients

Abstract

Background: Systemic lupus erythematosus (SLE) patients run a higher risk of having low bone mass due to multifactorial events that include physical inactivity, persistent inflammation, low vitamin D levels, and glucocorticoid treatment. This study aimed at obtaining a comparison between bone involvement in SLE patients and healthy matched subjects (HS). Methods: A total of 40 SLE females (average age 54.1 ± 16.3 years) and 40 age-gender matched HS (average age 54.2 ± 15.9 years) were enrolled after having obtained informed written consent. Bone mineral density (BMD, g/cm 2) of the lumbar spine (L1-L4) was analyzed by a dual-energy X-ray absorptiometry (DXA) scan (GE, Lunar Prodigy). The lumbar spine trabecular bone score (TBS) was derived for each spine DXA examination by the TBS index (TBS iNsight Medimaps). Results: The lumbar spine TBS score was statistically significantly lower in SLE patients than in HS (0.797 ± 0.825 vs. 1.398 ± 0.207, p < 0.001, as was BMD (p < 0.001) in all areas examined. Conclusions: SLE is associated with significant low bone mass as evidenced by DXA and TBS. This study emphasizes the importance of using DXA and TBS in the evaluation of the different aspects of bone architecture.

What Role Does Trabecular Bone Score Play in Chronic Inflammatory Rheumatic Diseases?

“…Moreover, a high prevalence of morphometric vertebral fractures has been observed in SLE patients, despite the fact that 1/3 of them had normal bone density, in line with the hypothesized multi-factorial etiology of fractures in SLE (14,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). Indeed, long-term use of corticosteroids may induce OP in SLE patients by influencing bone turnover (increasing bone resorption and decreasing bone formation), preventing the formation of collagen and osteocalcin, as well as reducing the bone matrix mineralization (14,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). Moreover, numerous cytokines are involved in OP pathogenesis, due to their influence on osteoblast and osteoclast function, i.e., IL-33 (35,(37)(38)(39).…”

“…Lai et al and Ruaro et al emphasized the important role TBS plays as an innovative and safe diagnostic tool for the quantification of bone quality in chronic and systemic inflammatory rheumatic diseases, such as those observed in SLE. In fact, both studies confirmed that SLE patients have a higher risk of bone loss (osteopenia and OP) and fractures than do HS (34,40).…”

“…Recent studies have demonstrated a higher incidence of OP and bone fractures in SLE patients compared to HS (14,(30)(31)(32)(33)(34)(35)(36). The bone loss observed in SLE has a multi-factorial etiology, including: systemic inflammation, kidney impairment, nutritional disorders, serological, metabolic, and hormonal factors and maybe also genetic factors and drugs, such as glucocorticoids (GC) (14,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). Moreover, a high prevalence of morphometric vertebral fractures has been observed in SLE patients, despite the fact that 1/3 of them had normal bone density, in line with the hypothesized multi-factorial etiology of fractures in SLE (14,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40).…”

“…The bone loss observed in SLE has a multi-factorial etiology, including: systemic inflammation, kidney impairment, nutritional disorders, serological, metabolic, and hormonal factors and maybe also genetic factors and drugs, such as glucocorticoids (GC) (14,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). Moreover, a high prevalence of morphometric vertebral fractures has been observed in SLE patients, despite the fact that 1/3 of them had normal bone density, in line with the hypothesized multi-factorial etiology of fractures in SLE (14,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40). Indeed, long-term use of corticosteroids may induce OP in SLE patients by influencing bone turnover (increasing bone resorption and decreasing bone formation), preventing the formation of collagen and osteocalcin, as well as reducing the bone matrix mineralization (14,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40).…”

“…Vitamin D deficiency may also be a predisposing factor for bone loss in SLE (14,35,(37)(38)(39). Several studies have demonstrated that SLE patients have an increased risk of low bone mass, assessed by DXA and TBS (14,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40).…”