The vitamin D status in ankylosing spondylitis in relation to intestinal inflammation, disease activity, and bone health: a cross-sectional study

Peripheral vitamin D levels in ankylosing spondylitis: A systematic review and meta-analysis

Objectives

Previous studies showed conflicting results regarding peripheral vitamin D levels in ankylosing spondylitis (AS). We performed this systemic review and meta-analysis to explore whether vitamin D may influence AS process.

Methods

Articles published until March 2022 were searched in databases as follows: PubMed, Web of Science, and Google Scholar. The present study included cross-sectional and case-control studies regarding vitamin D levels in patients with AS. Studies were excluded according to the following exclusion criteria: (1) we excluded studies which did not provide sufficient information regarding the comparison of vitamin D levels in AS patients and healthy controls (HC). Vitamin D levels in the two group studies should be reported or could be calculated in included studies; (2) meta-analysis, reviews and case reports. STATA 12.0 software was used to make a meta-analysis. Standard mean differences (SMDs) and 95% confidence intervals (CIs) were computed as effect size.

Results

The present meta-analysis showed no significant difference in peripheral 1,25-dihydroxyvitamin D3 (1,25OHD) levels between AS and healthy controls (HCs) in Caucasians with a random effects model [SMD: −0.68, 95% CI (−1.90, 0.54)]. Patients with AS had lower peripheral 25-hydroxyvitamin D (25OHD) levels compared with HC with a random effects model [SMD: −0.45, 95% CI: (−0.70, −0.20)]. Patients with AS had higher peripheral C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels compared with HC in Caucasian population with random effects models [CRP: SMD: 1.08, 95% CI: (0.78, 1.37); ESR: SMD: 0.86, 95% CI: (0.39, 1.34)]. However, no significant difference in alkaline phosphatase (ALP), parathyroid hormone (PTH) or calcium levels were indicated between AS and HC in Caucasian with random effects models [ALP: SMD: 0.07, 95% CI: (−0.41, 0.55); PTH: SMD: −0.15, 95% CI: (−0.56, 0.26); calcium: SMD: −0.06, 95% CI: (−0.39, 0.26)].

Conclusion

In conclusion, the study showed an inverse association between 25OHD and AS, which suggests that vitamin D may have a protective effect on AS. ESR and C-reactive protein (CRP) are important biomarkers for AS.

Vitamin D and risk of ankylosing spondylitis: A two-sample mendelian randomization study

OBJECTIVES

To study whether Vitamin D levels are causally associated with ankylosing spondylitis (AS).

METHODS

Two-sample Mendelian randomization (TSMR) analysis was performed by employing MR-Egger regression, weighted median (WM¹), inverse-variance weighted (IVW), and weight mode (WM²) methods. The odds ratio (OR) with 95% confidence intervals (CIs) was used to evaluate this association.

RESULTS

The results of IVW show that no causal association between vitamin D and AS (OR = 0.999, 95%CI = 0.997, 1.002, P = 0.724). The MR-Egger regression results show that genetic pleiotropy does not bias the results (intercept = -4.474E-05, SE = 2.830E-05, P = 0.255). The MR-Egger method no supported causal association between vitamin D and AS (OR = 1.000, 95%CI = 0.996, 1.005, P = 0.879). WM¹ (OR = 1.002, 95%CI = 0.999, 1.005, P = 0.837) and WM² (OR = 0.998, 95%CI = 0.996, 1.002, P = 0.910) approach also not found a causal relationship between vitamin D levels and AS. The significant heterogeneity was not observed by Cochran's Q test. The "leave-one-out" analysis also proved lack of a single SNP affected the robustness of our results.

CONCLUSION

Based on our analysis, there is lack of a strong evidence to support a causal inverse association between vitamin D levels and ankylosing spondylitis.

Ankylosing spondylitis risk factors: a systematic literature review

Radiographic axial spondyloarthritis (also known as ankylosing spondylitis [AS]) is a chronic immune-mediated arthritis characterized by inflammation of the axial skeleton, peripheral joints, and entheses. It is estimated that 1 in every 200 people are affected by AS, making it an important healthcare and socioeconomic issue. In this review, we aim to explore the current understanding of AS risk factors and provide a comprehensive update. Multiple search strings were used to identify articles of interest published in PubMed between January 1, 2013, and February 1, 2021. On the basis of the literature review and analysis, we present up-to-date information on the risk factors of developing AS and our viewpoints on disease onset and progression. Multiple genetic and nongenetic risk factors have been suggested in the onset of AS. HLA-B27 is known to have a strong association with the disease, but other genes have been implicated in disease development. Aside from genetics, other factors are thought to be involved; up to 70% of patients with AS have subclinical intestinal inflammation, suggesting that the origin of the disease may be in the gut. The exact mechanism by which AS onset begins is most likely complex and multifactorial. Key Points • It remains unclear how interactions between genes, microbes, mechanical stress, gender, and other environmental and lifestyle factors predispose patients to the development of ankylosing spondylitis (AS). • The exact mechanisms of AS are complex and multifactorial which will require much future research • Recognizing the risk factors, as well as understanding gene-environment interactions, may offer valuable insights into the etiology of AS and have important implications for diagnosis and treatment strategies.

Vitamin D Signaling in Gastro-Rheumatology: From Immuno-Modulation to Potential Clinical Applications

In the last decades, the comprehension of the pathophysiology of bone metabolism and its interconnections with multiple homeostatic processes has been consistently expanded. The branch of osteoimmunology specifically investigating the link between bone and immune system has been developed. Among molecular mediators potentially relevant in this field, vitamin D has been recently pointed out, and abnormalities of the vitamin D axis have been described in both in vitro and in vivo models of inflammatory bowel diseases (IBD) and arthritis. Furthermore, vitamin D deficiency has been reported in patients affected by IBD and chronic inflammatory arthritis, thus suggesting the intriguing possibility of impacting the disease activity by the administration vitamin D supplements. In the present review, the complex interwoven link between vitamin D signaling, gut barrier integrity, microbiota composition, and the immune system was examined. Potential clinical application exploiting vitamin D pathway in the context of IBD and arthritis is presented and critically discussed. A more detailed comprehension of the vitamin D effects and interactions at molecular level would allow one to achieve a novel therapeutic approach in gastro-rheumatologic inflammatory diseases through the design of specific trials and the optimization of treatment protocols.

Prevalence of Subclinical Carotid Atherosclerosis and Vitamin D Deficiency in Egyptian Ankylosing Spondylitis Patients

Objectives

This study aims to investigate the relationship between subclinical carotid atherosclerosis and vitamin D deficiency in Egyptian ankylosing spondylitis (AS) patients and their impact on disease activity.

Patients and methods

This cross-sectional study included 40 AS patients (36 males, 4 females; mean age 45.9±8.4 years; range 33 to 55 years) diagnosed according to the 1984 modified New York criteria with equal number of healthy controls (26 males, 14 females; mean age 48.4±7.8 years; range 31 to 55 years). Patients' histories were taken and clinical examinations were performed. Disease activity was assessed with Bath AS metrology index (BASMI), Bath AS disease activity index (BASDAI), and Bath AS functional index (BASFI) scores. Laboratory evaluation included lipid profile and 25-hydroxyvitamin D [25(OH)D] was determined by enzyme-linked immunosorbent assay. Bilateral carotid intima-media thickness (CIMT) was measured by a high-resolution ultrasound with linear 7-12 MHz transducer. Average of CIMT of right and left common carotid arteries was used.

Results

Statistically significant differences were found between patients and controls in terms of CIMT (p<0.001), 25(OH)D3 (p<0.001) and triglycerides (p=0.02). A significant positive correlation was present between CIMT and disease duration (r=0.74), disease activity scores [BASFI (r=0.60), BASMI (r=0.49), BASDAI (r=0.65)] and lipid profile except for high-density lipoprotein (HDL) that had a negative correlation (r=-0.52). A significant negative correlation was present between 25(OH)D3 levels and CIMT (r=-0.38) and lipid profile except for HDL having a positive correlation (r=0.40).

Conclusion

Prevalence of subclinical carotid atherosclerosis in AS patients compared to the healthy population was associated with high disease activity and functional limitations. In AS patients, 25(OH)D3 deficiency is a risk factor for accelerated atherosclerosis.

Dynamic changes in gut microbiota under the influence of smoking and TNF-α-blocker in patients with ankylosing spondylitis

OBJECTIVES

This study aimed to investigate the relationship among smoking, TNF-α-blocker therapy, and the dynamic changes in gut microbiota in patients with ankylosing spondylitis (AS).

METHODS

Using a 16S rRNA sequence, 98 fecal samples of 20 AS patients collected after 0, 1, 3 and 6 months of anti-TNF-α treatment and from 20 matched health controls were examined. The variation in composition, abundance, and diversity of gut microbiota was analyzed. The dynamic effects of smoking and treatment on gut microbiota and therapeutic efficacy in AS patients were studied.

RESULTS

The increased relative abundance of microbiota in AS nonsmokers was g_Comamonas and g_Desulfovibrio, while that in AS smokers was g_Actinomyces, g_Collinsella, g_Lachnospiraceae_UCG-008, and g_Paraprevotella. The relative abundance of gut microbiota showed dynamic variation. The improvement rate of ASDAS in AS nonsmokers was higher than that in AS smokers (2.297 vs 1.736) after anti-TNF-α treatment. The β-diversity of gut microbiota in AS smokers was lower than that in AS nonsmokers and improved with treatment.

CONCLUSIONS

Both smoking and TNF-α-blocker had significant effects on the composition, relative abundance, and diversity of gut microbiota in AS patients. The AS smokers characteristically shared g_Collinsella and g_Dorea. The relative abundance of gut microbiota revealed high variability and was in dynamic fluctuation during treatment. The response of gut microbiota to anti-TNF-α treatment was found to be heterogeneous and selective. AS nonsmokers showed a greater improvement rate of ASDAS-CRP with treatment than AS smokers did. The AS smokers showed a lower β-diversity of gut microbiota, and improved after treatment. Key Points • Characterized the dynamic variation in gut microbiota in AS patients classified as smokers and nonsmokers during treatment with anti-TNF-α. • Confirmed the interaction between smoking, anti-TNF-α therapy, and gut microbiota.

Pathophysiological Role and Therapeutic Implications of Vitamin D in Autoimmunity: Focus on Chronic Autoimmune Diseases

Vitamin D is a pleiotropic secosteroid yielding multiple actions in human physiology. Besides the canonical regulatory activity on bone metabolism, several non-classical actions have been described and the ability of vitamin D to partake in the regulation of the immune system is particularly interesting, though far stronger and convincing evidence has been collected in in vitro as compared to in vivo studies. Whether vitamin D is able to regulate at physiological concentrations the human immune system remains unproven to date. Consequently, it is not established if vitamin D status is a factor involved in the pathogenesis of immune-mediated diseases and if cholecalciferol supplementation acts as an adjuvant for autoimmune diseases. The development of autoimmunity is a heterogeneous process, which may involve different organs and systems with a wide range of clinical implications. In the present paper, we reviewed the current evidences regarding vitamin D role in the pathogenesis and management of different autoimmune diseases.

Relationship between Vitamin D levels and pain and disease activity in patients with newly diagnosed axial spondyloarthritis

OBJECTIVES

To explore the relationship between Vitamin D levels and pain and disease activity in patients with newly diagnosed axial spondyloarthritis (axSpA).

METHODS

A convenience sample of 131 newly diagnosed axSpA patients and 60 healthy controls was recruited from July 2016 to December 2018. Serum 25-hydroxyvitamin D [25(OH)D] was measured to assess vitamin D levels. Disease activity was assessed by objective indicators [Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), the Bath Ankylosing Spondylitis Metrology Index (BASMI)], patient-reported questionnaires [the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), and the Bath Ankylosing Spondylitis Functional Index (BASFI)]. Pain intensity and interference were also assessed.

RESULTS

Vitamin D insufficiency [serum 25(OH) D levels<50 nmol/L]was found in 46 (35.1%) and 25 (43.3%) of the axSpA patients and the healthy controls, respectively. Female patients had higher risk (OR:4.928; 95% CI: 1.921-12.642) for vitamin D insufficiency than male patients. Vitamin D was positively correlated with CRP, ESR level, the BASFI, and the BASMI. Logistic regression showed that vitamin D levels were not associated with pain, or disease activity in the newly diagnosed axSpA patients. Gender was the only predictive variable for vitamin D levels.

CONCLUSIONS

Vitamin D insufficiency was prevalent in both newly diagnosed axSpA patients and healthy controls. There was no association between vitamin D and pain and disease activity in the newly diagnosed axSpA patients. Monitoring vitamin D levels is important and early intervention for vitamin D insufficiency is needed, especially in female patients.

Vitamin D and Spondyloarthritis: Review of the Literature

Background:

Spondyloarthritides (SpAs) encompass heterogeneous diseases sharing similar genetic background, pathogenic mechanisms, and phenotypic features. Vitamin D is essential for calcium metabolism and skeletal homeostasis. Some recent evidences reported supplemental functions of vitamin D, such as modulation of inflammatory reactions.

Objective:

To analyze published data about a possible association between vitamin D and SpAs.

Results:

Vitamin D could play a role in immune reactions, influencing both immune and adaptive response. Vitamin D deficiency is more frequent in SpAs than in general population: an active and more severe disease infers patients’ mobility and reduces sunlight exposure. Quiescent inflammatory bowel disease, frequently associated with SpAs, could worsen vitamin D deficiency. All the parameters related to UVB exposure are the most important determinants for vitamin D status and need to be considered evaluating the vitamin D levels in SpAs.

Apart from musculoskeletal problems, patients affected by SpAs frequently suffer from other comorbidities, especially cardiovascular diseases and osteoporosis, and vitamin D status could have a relevance in this field. Bone is involved in SpAs with a dualistic role, coexisting trabecular bone resorption and new bone formation.

It seems rational to monitor vitamin D levels in SpA subjects and to target it to global health threshold.

Conclusion:

Literature data were not completely in agreement about a possible relation between poor vitamin D status and onset or worse disease course of SpAs. In fact, these results come from cross-sectional studies, which affect our ability to infer causality. Therefore, large, randomized controlled trials are needed.

Vitamin D serum concentration is not related to the activity of spondyloarthritis - preliminary study

Objective

Vitamin D plays an important role in mineral turnover and bone remodeling and there are increasing data about its immunomodulatory potential in different rheumatologic disorders. Deficiency of vitamin D is frequent in patients with spondyloarthritis (SpA) and some data suggest its association with increased disease activity and structural damage. However, its exact role in the pathogenesis of SpA and its association with disease activity are still a matter of debate.

Material and methods

A cross-sectional study of patients diagnosed with axial spondyloarthritis (axSpA) and peripheral spondyloarthritis (perSpA) according to Assessment of Spondyloarthritis International Society classification criteria was performed. The correlation between concentration of 25-hydroxyvitamin D – 25(OH)D – and disease activity scores (Bath Ankylosing Spondylitis Disease Activity Index – BASDAI, Ankylosing Spondylitis Disease Activity Score – ASDAS), inflammatory markers (C-reactive protein – CRP, erythrocyte sedimentation rate – ESR) and clinical symptoms (arthritis, enthesitis, dactylitis) was performed.

Results

We included 40 patients with axSpA and 23 patients with perSpA. The mean concentration of 25(OH)D was 24.9 ng/ml (SD 12.49). Forty-seven (74.6%) patients had 25(OH)D below the recommended threshold (< 30 ng/ml). We found no statistically significant negative correlation between the level of 25(OH)D and disease activity of axSpA and perSpA in terms of clinical symptoms (arthritis, enthesitis, dactylitis), inflammatory markers (ESR, CRP) and disease activity scores (BASDAI, ASDAS). These results did not change after adjustment for supplementation of vitamin D and seasonal variation.

Conclusions

Our data show no correlation between the concentration of 25(OH)D in the serum and disease activity in two subgroups of SpA. However, this does not exclude the potential role of vitamin D in pathogenesis of SpA. Further studies are required to evaluate the optimal range of 25(OH)D serum concentration in axSpA and perSpA patients with its possible immunomodulatory potential and influence on disease activity.

Recent advances in ankylosing spondylitis: understanding the disease and management

The term spondyloarthritis refers to a group of immune-mediated diseases characterised by inflammation of the axial skeleton, peripheral joints, and entheses. Ankylosing spondylitis (AS) is the most common and characteristic of these entities and even though it was first described over two centuries ago, the understanding of the underlying disease mechanism remains incomplete. It is known that around 40% of patients with AS have subclinical bowel inflammation, suggesting that the origin of the disease could be in the gut. Also, more genes and new molecules have demonstrated a role in the pathogenesis of AS. In this review, we analyse the latest therapies for spondyloarthritis and the most relevant discoveries over the last three years, together with their implications for different aspects of the disease.

Prevalence and risk factors for osteoporosis and fractures in axial spondyloarthritis: A systematic review and meta-analysis

OBJECTIVES

To describe the prevalence of osteoporosis, the prevalence and incidence of fractures, and the frequency of risk factors for low bone mineral density (BMD) in axial spondyloarthritis (Ax-SpA).

METHODS

A systematic review and meta-analysis of observational studies was conducted. Medline, Embase, and Cochrane Library databases were searched with a sensitive strategy. Large cross-sectional and longitudinal studies published in the last 10 years (January 2006-2016) with representative samples of patients with Ax-SpA estimating the frequency of osteoporosis, risk factors or fractures were selected.

RESULTS

After screening 3597 titles and abstracts, 46 studies were reviewed in detail, of which 35 studies had a cross-sectional design, 5 were prospective and 6 retrospective; 21 studies compared Ax-SpA patients with a control group-either healthy individuals (18 studies) or subjects with other diseases (6 studies). The prevalence of osteoporosis varied from 11.7% to 34.4% and that of fractures from 11% to 24.6%. Alcohol intake (58-61%), use of corticosteroids (11.7-66.9%), and 25-OH vitamin D deficiency (26-76%) were unexpectedly high in Ax-SpA patients.

CONCLUSION

The prevalence of osteoporosis and fractures in Ax-SpA varies between 11.7% and 34.4% and 11-24.6%, respectively. Alcohol intake, steroid use, and low levels of 25-OH-vitamin D should be taken into account in osteoporosis assessment in patients with Ax-SpA. Inconsistent results, lack of bone quality assessment, and high likelihood of bias of the published studies confirm the need for performing well-designed studies.

Are Systematic Screening for Vitamin D Deficiency and Vitamin D Supplementation Currently Feasible for Ankylosing Spondylitis Patients?

Beyond its role in calcium and phosphorus metabolism for healthy bone mineralization, there is increasing awareness for vitamin D contribution in modulation of immune reactions. Given that ankylosing spondylitis (AS) is a chronic inflammatory disease involving excess immune/inflammatory activity and posing great therapeutic challenges, it is conceivable to claim that vitamin D treatment may be a safe and effective treatment to influence or modify the primary disease and its related comorbidities. Nevertheless, consistent body of research supporting this hypothesis is still lacking. In this paper, we examine whether systematic screening and treatment for vitamin D deficiency are feasible at present. We will review the immunomodulatory role of vitamin D and its contribution in initiation and progression of AS, as well as how they would determine the occurrence of comorbid conditions. Our conclusion is that despite the overwhelmed interest about vitamin D treatment in AS patients, systematic screening and treatment for vitamin D deficiency of all AS patients are not feasible as yet. This stresses the need for further extensive well-designed research to prove vitamin D efficacy in AS beyond bone protection. And if utility is proven, personalized treatment regimes, duration of treatment, and threshold values for vitamin D should be provided.

Osteoporosis Management in Ankylosing Spondylitis

Low bone mineral density (BMD) is increasingly recognized as a common comorbid condition in ankylosing spondylitis (AS). As low BMD increases fracture risk, it is important to identify and treat low BMD in patients with AS who have been shown to be at increased risk for fractures above the population normal. Since low BMD occurs early in disease, we screen during the first year of diagnosis with dual energy x-ray absorptiometry (DXA). If patients are found to have osteoporosis by T-score of less than -2.5 or if their Z-score on DXA is more than two standard deviations below the mean, we initiate therapy with bisphosphonates in males and in females who are not planning any future pregnancies. While reduction in fracture risk with bisphosphonate therapy has not been clearly defined in patients with AS, reduction in vertebral and hip fractures has been well established in primary osteoporosis and thus it is our first line treatment. If there are contraindications to the use of bisphosphonates in the treatment of low BMD, we will consider the use of denosumab. If the patient is not receiving a TNF-alpha inhibitor (TNFi) and has active disease, we also favor early initiation of TNFi due to their positive effects on BMD though the outcome on reduction in vertebral fractures remains unclear. We counsel all patients regarding the importance of adequate intake of vitamin D and calcium per the Institute of Medicine guidelines. All patients should be encouraged to participate in weight-bearing activities with a focus on core strength and gait training.