Bone tissue metabolism in men with ankylosing spondylitis

Development and validation of a nomogram for predicting low bone mineral density in male patients with ankylosing spondylitis

Objective

This retrospective cohort study aimed to develop and validate clinical nomogram models for predicting site-specific low bone mineral density (BMD) risk in male patients with ankylosing spondylitis (AS).

Methods

This study enrolled male AS patients treated at the Rheumatology Department of Jiangsu Provincial Hospital of Traditional Chinese Medicine between January 2017 and September 2024. A total of 322 eligible patients were randomly allocated to training and validation cohorts at a 7:3 ratio. Potential predictors of low BMD at the lumbar spine (LS) and left hip (LH) were initially screened through univariate logistic regression (p < 0.05), followed by stepwise bidirectional multivariate logistic regression (entry criteria p < 0.05) to identify independent predictors for each anatomical site. Based on the regression coefficients, we developed visualized nomogram prediction models for LS and LH low BMD, accompanied by an interactive online prediction tool. The models were comprehensively evaluated for discrimination, calibration, and clinical utility. After identifying the primary predictive factors, exploratory subgroup analyses were conducted to assess effect heterogeneity of key variables (BMI and serum uric acid).

Results

This study included 322 male AS patients randomly allocated to training (n = 225) and validation (n = 97) cohorts with balanced baseline characteristics (all p > 0.05). Multivariate logistic regression identified age at onset (LS OR = 0.96, 95%CI:0.93-0.99; LH OR = 0.97, 95%CI: 0.95-0.99), BMI (LS OR = 0.90, 95%CI: 0.81-0.99; LH OR = 0.81, 95%CI: 0.72-0.91), serum uric acid (LS/LH OR = 0.99, 95%CI: 0.99-0.99), and hip involvement (LS OR = 3.22, 95%CI: 1.71-6.05; LH OR = 8.03, 95%CI: 4.01-16.09) as common independent predictors for low BMD at both sites, while serum calcium (OR = 12.19, 95%CI: 1.44-103.25) was specific to LS. The developed nomograms, including web-based versions, demonstrated good discrimination (LS AUC: 0.77 training/0.73 validation; LH AUC: 0.82/0.85) and calibration. Decision curve analysis revealed significant net clinical benefit across probability thresholds (LS: 0.17-0.86 training/0.20-0.82 validation; LH: 0.15-0.92/0.27-0.91). The protective effect of BMI exhibited site-specific patterns: LS (low-TC: OR = 0.86; high-TC: OR = 0.77), LH (low-TC: OR = 0.77; mid-TC: OR = 0.74), with the most pronounced effect observed in the LS low-TG subgroup (OR = 0.79). SUA demonstrated consistent protective effects (LS/LH: OR = 0.95-0.99, all p < 0.05), potentially independent of disease stage. Interaction analyses revealed that neither lipid levels nor disease stage significantly modified the effects of BMI and SUA (all interaction p > 0.4).

Conclusion

This study developed clinical prediction models with excellent discriminative ability and substantial clinical utility for male patients with AS. These models offer rheumatologists an efficient tool to rapidly assess individual risks of low BMD, facilitating early diagnostic decision-making and enabling personalized interventions tailored to anatomical site-specific osteoporosis risks.

A Contemporary View of the Diagnosis of Osteoporosis in Patients With Axial Spondyloarthritis

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that primarily affects the axial joints. Altered bone metabolism associated with chronic inflammation leads to both new bone formation in the spine and increased bone loss. It is known that patients with axSpA have a high prevalence of osteoporosis and fractures. However, there is no consensus on which imaging modality is the most appropriate for diagnosing osteoporosis in axSpA. Bone mineral density measurement using dual-energy X-ray absorptiometry is the primary diagnostic method for osteoporosis, but it has notable limitations in patients with axSpA. This method may lead to the overestimation of bone density in patients with axSpA because they often exhibit abnormal calcification of spinal ligaments or syndesmophytes. Therefore, the method may not provide adequate information about bone microarchitecture. These limitations result in the underdiagnosis of osteoporosis. Recently, new imaging techniques, such as high-resolution peripheral quantitative computed tomography, and trabecular bone score have been introduced for the evaluation of osteoporosis risk in patients with axSpA. In this review, we summarize the current knowledge regarding imaging techniques for diagnosing osteoporosis in patients with axSpA.

Effects of etanercept and infliximab on bone metabolism indexes in patients with ankylosing spondylitis

Effect of etanercept and infliximab on bone metabolism indexes in patients with ankylosing spondylitis (AS) were evaluated. The clinical data of 80 patients with ankylosing spondylitis admitted to Affiliated Hospital of Hebei University of Engineering from June 2015 to March 2016 were selected. There were 39 patients treated with Enbrel as Enbrel group and 41 patients treated with Infliximab as Infliximab group. The general data of the two groups of patients were collected and various indexes before and 12 and 24 weeks after treatment were recorded. Adverse reactions of the two groups of patients after treatment were recorded and the clinical efficacy of the drugs was evaluated. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels in both groups decreased significantly before and 12 and 24 weeks after treatment (P<0.05), and 24 weeks after treatment showed a downward trend compared with 12 weeks (P<0.05). The β-collagen special sequence (β-CTX) level in the two groups was significantly lower after treatment than before (P<0.0001). The adverse reaction rate of Infliximab group (21.95%) was higher than that of Enbrel group (5.13%) (P>0.05). The morning stiffness time, BASDAI and BASFI indexes of the two groups of patients after treatment were significantly lower than those before treatment (P<0.0001). Schober test was significantly higher than that before treatment (P<0.0001); BASDAI in Infliximab group was lower than that in etanercept group (P<0.05). Both etanercept and infliximab have good therapeutic effects on AS, which can reduce the bone metabolism level of β-CTX in AS patients and effectively improve the symptoms of affected medullary joints. The short-term efficacy of the two groups of patients is similar, but the incidence of adverse reactions of etanercept is slightly lower than that of infliximab.

MULTIDIRECTIONAL ASSESSMENT OF BONE STRUCTURE INCLUDING RADIOISOTOPIC ANALYSIS IN PERIMENOPAUSAL WOMEN

OBJECTIVE

In postmenopausal period, changes in bone turnover markers (BTM), vitamin D3, cytokines and parathyroid hormone (PTH) are frequently observed. The study was to assess bone mineral density (BMD) and bone metabolism index (IBM) in the perimenopausal women.

DESIGN YEARS

2013-2014.

SUBJECTS AND METHODS

One hundred and thirteen women were divided into four groups: group I (35 not menstruating 50 - 60 years old with osteoporosis), II (23 not menstruating 50 - 60 years old without osteoporosis), III (30 menstruating 40 - 49 years old with osteoporosis), IV (25 menstruating 40 - 49 years old without osteoporosis). The following parameters were measured: IL-1β, IL-6, TNF-α, hormone oestradiol (E2), PTH, FSH, TSH, calcium (Ca2+), phosphates (P), alkaline phosphatase (bALP), C-terminal telopeptide of type I collagen alpha 1 chain (α1CTX), osteocalcin (OC), BMD, IBM.

RESULTS

IBM and BMD were significantly lower in premenopausal than in postmenopausal women. The concentration of OC, CTX, 25OH D3 and PTH levels differed significantly between group I vs. II, group I vs. III and group II vs. IV.

CONCLUSIONS

The levels of BTM, D3, PTH differed significantly between groups. This study demonstrated that bone metabolism depended mainly on processes related with menopause state and changes in D3, PTH and cytokines levels.

EULAR recommendations for the use of imaging in the diagnosis and management of spondyloarthritis in clinical practice

A taskforce comprised of an expert group of 21 rheumatologists, radiologists and methodologists from 11 countries developed evidence-based recommendations on the use of imaging in the clinical management of both axial and peripheral spondyloarthritis (SpA). Twelve key questions on the role of imaging in SpA were generated using a process of discussion and consensus. Imaging modalities included conventional radiography, ultrasound, magnetic resonance imaging, computed tomography (CT), positron emission tomography, single photon emission CT, dual-emission x-ray absorptiometry and scintigraphy. Experts applied research evidence obtained from systematic literature reviews using MEDLINE and EMBASE to develop a set of 10 recommendations. The strength of recommendations (SOR) was assessed by taskforce members using a visual analogue scale. A total of 7550 references were identified in the search process, from which 158 studies were included in the systematic review. Ten recommendations were produced using research-based evidence and expert opinion encompassing the role of imaging in making a diagnosis of axial SpA or peripheral SpA, monitoring inflammation and damage, predicting outcome, response to treatment, and detecting spinal fractures and osteoporosis. The SOR for each recommendation was generally very high (range 8.9-9.5). These are the first recommendations which encompass the entire spectrum of SpA and evaluate the full role of all commonly used imaging modalities. We aimed to produce recommendations that are practical and valuable in daily practice for rheumatologists, radiologists and general practitioners.

The Relationship of Bone Mineral Density to Oxidant/Antioxidant Status and Inflammatory and Bone Turnover Markers in a Multicenter Cross-Sectional Study of Young Men with Ankylosing Spondylitis

Low bone mineral density (BMD) is an important complication of ankylosing spondylitis (AS) that seriously affects men and their quality of life, even in young patients. However, the relationships among redox; levels of bone turnover markers (BTMs), inflammatory markers and disease activity; and low BMD in AS require clarification. We recruited 102 men aged 30-39 year with AS and 102 healthy, sex- and age-matched controls for this cross-sectional study. The subjects were analyzed for lumbar spine and femoral neck BMD by dual-energy X-ray absorptiometry. Significantly lower BMD and corresponding T-scores were observed in the AS patients compared with the controls (P < 0.05). The oxidant biomarker and antioxidant levels were significantly (P < 0.05) higher and lower, respectively, in the AS subjects compared with the controls, and the bone resorption and inflammatory marker levels were higher (P < 0.05). In subgroup analyses, the patients with osteoporosis or active disease had the highest levels of oxidant biomarkers (P < 0.05). Furthermore, the BMD T-scores in AS were found to be negatively correlated with oxidative status (P < 0.05). Multivariate binary logistic analysis showed that low BMD in the AS patients was associated with higher levels of advanced oxidation protein products, malondialdehyde and C-terminal telopeptide of type I collagen; lower levels of glutathione peroxidase; and higher scores of a bath ankylosing spondylitis metrology index. In conclusion, imbalanced redox was independently associated with low BMD in young men with AS and may play an important role in the pathogenesis of AS-related low BMD.

Bone mass in axial spondyloarthritis: A literature review

AIM: To review the published literature reporting bone loss in patients with axial spondyloarthritis (SpA) particularly those studies using dual X-ray absorptiometry (DXA) methods.

METHODS: This literature review examines the reported bone mass in patients with ax-SpA, particularly those using the DXA methods. The MEDLINE, Web of Science and Scopus databases were searched for relevant articles published between September 1992 and November 2013. Some of used search terms were ankylosing spondylitis (AS), SpA, spondyloarthropathy, bone loss, bone mass, osteopenia, bone mineral density, osteoporosis (OP), densitometry. Studies in which bone loss was investigated by using DXA in patients with SpA were eligible. Each article was reviewed and the key elements were noted.

RESULTS: There were 286 hits on MEDLINE, 200 on Web of Science and 476 on Scopus. After applying inclusion and exclusion criteria, we identified 55 articles in our systematic search. The sample size of the studies varied from 14 to 332 patients with SpA. The reported age range varied from 25 to 56 years in the reviewed studies. The symptom duration of patients with axSpA varied from 1.6 to 49 years. There were more males than females in these studies. Most of the recruited females were premenopausal women. Reported HLA-B27 positivity changed between 19% to 95%. The prevalence of OP and osteopenia in patients with SpA varied from 3%-47% to 5%-88%, respectively, in the included studies. In particular, the prevalence of OP and osteopenia ranged from 2.0%-47.0% and 5.0%-78.3%, respectively, in patients with AS. There are conflicting results regarding the relationship among disease activity, acute phase response and bone mass. Some studies suggest good correlation of bone mass with disease activity and acute phase reactants.

CONCLUSION: Bone loss may be determined in patients with axSpA at the lumbar spine or proximal femur even in the early phase of the disease and may be associated with inflammation (bone marrow edema) at the vertebral colon.