Circulating leptin and its correlation with rheumatoid arthritis activity: a meta-analysis

Association between IL and 6 gene polymorphisms and circulating IL-6 levels in Behcet's disease: A meta-analysis

OBJECTIVES

This study aimed to investigate the association between circulating interleukin-6 (IL-6) levels and Behçet's disease (BD), and associations between polymorphisms in IL-6 gene and BD susceptibility.

METHOD

A search of relevant articles was conducted in the Medline, Embase, and Web of Sciences databases. Subsequently, a meta-analysis was performed to assess circulating IL-6 levels in both the BD and control groups. Additionally, we investigated the association between the functional IL-6 promoter -174 G/C polymorphism and the risk of developing BD.

RESULTS

Nineteen studies involving 923 patients with BD and 910 controls were included in this meta-analysis. The results demonstrated a significant elevation in circulating IL-6 levels in the BD group than in the control group (standardized mean difference [SMD] = 1.600, 95 % confidence interval [CI] = 0.732-2.496, P<0.001). Furthermore, IL-6 levels were significantly higher in the active disease group than in the inactive disease group (SMD=1.292, 95 % CI=0.059-2.525, P<0.001). Intriguingly, the meta-analysis revealed an association between BD and the IL-6 CC+CG genotype in Arabs (odds ratio [OR] = 0.588, 95 % CI=0.393-0.881, P=0.010), whereas no such association was observed in European or Asian populations.

CONCLUSIONS

Our meta-analysis revealed significantly higher circulating IL-6 levels in patients with BD and found evidence of association between IL and 6 promoter -174 G/C and BD susceptibility.

Association of circulating leptin, growth hormone, and ghrelin with fibromyalgia: A meta-analysis

OBJECTIVE

The aim of this study was to evaluate the relationship between levels of leptin, growth hormone (GH), and ghrelin in the bloodstream and fibromyalgia.

METHODS

We conducted a meta-analysis to compare the serum/plasma levels of leptin, GH, and ghrelin in individuals with fibromyalgia, as compared to healthy controls. The analysis included sixteen articles, which provided data from 697 fibromyalgia patients and 560 controls.

RESULTS

The meta-analysis found that there was no significant difference in leptin levels between fibromyalgia patients and controls overall (SMD = 0.324, 95% CI = -0.264 to 0.913, P = 0.281). However, when subgroup analysis was done based on geographically different populations, it showed a positive association between high leptin levels and fibromyalgia in European populations (SMD = 1.131, 95% CI = 0.197 to 2.064, P = 0.018), while no significant association was found in Latin American populations (SMD = -0.160, 95% CI = -0.847 to 0.528, P = 0.649). As for GH levels, there was no significant difference between fibromyalgia patients and controls overall (SMD = -0.903, 95% CI = -2.036 to 0.231, P = 0.119). However, when subgroup analysis was done based on geographically different populations, it revealed a significant decrease in GH levels in European populations with fibromyalgia (SMD = -2.341, 95% CI = -3.664 to -1.017, P = 0.001), while no significant association was found in North American populations. Lastly, the analysis of ghrelin levels showed no significant association with fibromyalgia overall (SMD = -0.661, 95% CI = -1.382 to 0.059, P = 0.072).

CONCLUSION

This meta-analysis shows that patients with fibromyalgia in Europeans have significantly higher levels of circulating leptin and GH. However, no significant association was found between ghrelin levels and fibromyalgia.

Association between chemokine genes polymorphisms and susceptibility to Parkinson's disease: a meta-analysis and systematic review

OBJECTIVE

This study aimed to investigate the potential association between polymorphisms in monocyte chemoattractant protein-1 (MCP-1), chemokine receptor type 2 (CCR2), type 5 (CCR5), regulated on activation, normal T cell expressed, and secreted (RANTES) and susceptibility to Parkinson's disease (PD).

METHODS

The MEDLINE, EMBASE, and Web of Science databases were searched for relevant articles, and a meta-analysis was conducted to assess the associations between the MCP-1 -2518 G/A, CCR2 V64I, CCR5-Δ32, RANTES - 405 G/A, -28 G/A polymorphisms and the risk of PD.

RESULTS

Six studies with 1,416 patients with PD and 1,715 controls that met the inclusion criteria were identified. Meta-analysis of all study participants demonstrated no association between PD and the MCP-1 -2518 G allele (odds ratio [OR] = 1.089, 95% confidence interval [CI] = 0.980-1.211, p = 0.114). Stratification by ethnicity indicated no association between the MCP-1 -2518 G allele and PD in the European and Asian populations. Meta-analysis demonstrated no association between PD and the MCP-1-2518 A/G polymorphism in recessive and dominant models and homozygote contrast. However, meta-analysis revealed a significant association between the risk of PD and the CCR2-V64I AA + GG genotype in all study participants (OR = 0.418, 95% CI = 0.232-0.753, p = 0.004). Stratification based on ethnicity validated this association between the CCR2-V64I AA + GG genotype and PD in the Asian population (OR = 0.460, 95% CI = 0.243-0.870, p = 0.017), but not in European populations. Analysis using the homozygous contrast model revealed the same pattern for the CCR2-V64I AA + GG genotype. Meta-analysis revealed no association between the CCR5-Δ32 allele and the risk of PD (OR = 0.972, 95% CI = 0.377-2.501, p = 0.952). Moreover, the meta-analysis demonstrated no allelic association between RANTES - 405 G/A and - 28 G/A polymorphisms and the risk of PD.

CONCLUSIONS

Our meta-analysis showed that the CCR2 V64I polymorphism is associated with PD, especially in Asian populations.

Adipokines as potential pharmacological targets for immune inflammatory rheumatic diseases: Focus on rheumatoid arthritis, osteoarthritis, and intervertebral disc degeneration

Adipokines are a heterogeneous group of signalling molecules secreted prevalently by adipose tissue. Initially considered as regulators of energy metabolism and appetite, adipokines have been recognized for their substantial involvement in musculoskeletal disorders, including osteoarthritis, rheumatoid arthritis, and many others. Understanding the role of adipokines in rheumatic inflammatory and autoimmune diseases, as well as in other musculoskeletal diseases such as intervertebral disc degeneration, is crucial for the development of novel therapeutic strategies. Targeting adipokines, or their signalling pathways, may offer new opportunities for the treatment and management of these conditions. By modulating adipokines levels or activity, it may be possible to regulate inflammation, to maintain bone health, and preserve muscle mass, thereby improving the outcomes and quality of life for individuals affected by musculoskeletal diseases. The aim of this review article is to update the reader on the multifaceted role of adipokines in the main rheumatic diseases such as osteoarthritis and rheumatoid arthritis and to unravel the complex interplay among adipokines, cartilage metabolism, bone remodelling and muscles, which will pave the way for innovative therapeutic intervention in the future. For completeness, the role of adipokines in intervertebral disc degeneration will be also addressed.

All-cause and cause-specific mortality in rheumatoid arthritis: a meta-analysis

OBJECTIVE

This study aimed to evaluate standardized mortality ratios (SMRs) for both all-cause and cause-specific mortality in patients with rheumatoid arthritis (RA).

METHODS

We conducted an extensive search across the Medline, Embase, and Cochrane databases to identify studies investigating SMRs for all-cause and/or cause-specific mortality in individuals with RA compared to the general population. Subsequently, we performed a comprehensive meta-analysis, examining SMRs across various categories, including all-cause, sex-specific, ethnicity-specific, and cause-specific SMRs in RA patients.

RESULTS

Seventeen studies involving 486,098 patients with RA and 63,988 deaths met the inclusion criteria. Patients with RA had a 1.522-fold increase in all-cause SMR (SMR 1.522, 95% CI 1.340-1.704, p < 0.001) compared to the general population. Stratification by ethnicity revealed that the all-cause SMR was 1.575 (95% CI 1.207-1.943) in Caucasians and 1.355 (95% CI 1.140-1.569) in Asians. The gender-specific meta-analysis revealed elevated SMR in both women and men. RA patients exhibited an increased risk of mortality attributed to cardiovascular disease (CVD), respiratory disease, infection, and cerebrovascular accidents (CVA). However, no significant increase in SMR was observed for mortality due to malignancy.

CONCLUSION

This meta-analysis study highlights a 1.522-fold increase in SMR in patients with RA compared to that in the general population, irrespective of sex or region. Additionally, a notable increase in mortality associated with specific causes, including CVD, respiratory disease, infection, and CVA, underscores the critical need for targeted interventions to manage these heightened risks in patients with RA.

Association between Mean Platelet Volume and Systemic Lupus Erythematosus: A Meta-Analysis

Background

This meta-analysis aimed to investigate the association between mean platelet volume (MPV) and systemic lupus erythematosus (SLE) disease activity, and laboratory parameters including the SLE Disease Activity Index (SLEDAI), C3 levels, anti-double-stranded DNA (anti-dsDNA) antibodies, and erythrocyte sedimentation rate (ESR).

Methods

The Medline, Embase, and Cochrane databases were searched comprehensively to identify relevant articles. Meta-Analyses were performed to assess differences in MPV between patients with SLE and control groups and between active and inactive SLE. A separate meta-analysis explored correlation coefficients between MPV and SLEDAI, C3, anti-dsDNA, and ESR.

Results

Fourteen studies comprising 659 patients with SLE and 682 controls were included. No significant difference in MPV was found between patients with SLE and control groups (standardized mean difference [SMD]: 0.406; 95% confidence interval [CI]: -0.087 to 0.899; P = 0.107). When stratified by ethnicity, the Arab population displayed markedly elevated MPV levels within the SLE group (SMD: 1.032; 95% CI: 0.475-1.588; P <0.001), unlike their European and Asian counterparts. MPV levels were higher in the active disease group than in the inactive group, particularly among the Arab population (SMD: 2.100; 95% CI: 0.406-3.794; P = 0.015), while no significant difference was observed within the Asian population (SMD: -1.493; 95% CI = -4.465 to 1.479; P = 0.325). MPV did not correlate with SLEDAI (correlation coefficient: 0.252; 95% CI: -0.016 to 0.486; P = 0.065), ESR, C3, or anti-dsDNA.

Conclusion

MPV levels were generally higher in patients with SLE among the Arab population. Moreover, MPV and disease activity were positively correlated within the Arab population, underscoring the potential of MPV as a disease activity indicator in specific ethnic groups.

Associations of toll-like receptor polymorphisms with systemic lupus erythematosus: A meta-analysis

Objective

The objective of this study was to examine whether polymorphisms in toll-like receptors 7 and 4 (TLR7 and 4) contribute to vulnerability to systemic lupus erythematosus (SLE).

Methods

We searched MEDLINE, Embase, and Web of Science for relevant articles and performed a meta-analysis to investigate the relationship between TLR7 rs179008, rs3853839, rs1790010, TLR4 rs4986791, and rs798690 polymorphisms and SLE.

Results

Eighteen studies and 16 papers including 8022 patients with SLE and 9822 healthy controls were retrieved. Meta-analysis revealed that the TLR7 rs179008 T variant was not associated with SLE (OR = 1.008, 95% CI = 0.849-1.394, P = 0.504). Ethnic classification revealed no association between the TLR7 rs179008 T gene and SLE in either European or Latin American groups. Additionally, homozygous comparison, recessive, and dominant models revealed no association between the TLR7 rs179008 variant and SLE. In contrast, a significant association between SLE and the TLR7 rsrs3853839 GG + GA allele (OR = 2.135, 95% CI = 1.502-3.035, <0.001; OR = 23.20, 95% CI = 14.13-38.08, <0.001) was observed in the Arab and Asian groups. The T variant of TLR7 rsrs179010 was also associated with SLE in Asians (OR = 1.177, 95% CI = 1.048-1.321, P = 0.006). In contrast, the TLR4 rs4986791 variant was not associated with SLE in Europeans when allele, homozygous comparison, recessive, and dominant models were used. Furthermore, no association between the TLR4 rs4986790 variant and SLE risk in Europeans was found using any genomic model.

Conclusions

Meta-analysis revealed that the TLR7 rs3853839 variant is associated with SLE risk in Asians and Arabs and that TLR7 rs179010 is associated with SLE in Asians. However, TLR7 rs179008, TLR4 rs4986791, and TLR rs798690 polymorphisms were not associated with SLE risk.

A meta-analysis of the association between the ATIC 347 C/G polymorphism and methotrexate responsiveness and toxicity in rheumatoid arthritis

OBJECTIVES

The purpose of this study was to determine whether the 347 C/G polymorphism in the 5-aminoimidazole-4-carboxamide ribonucleotide transformylase (ATIC) gene predicts the responsiveness to or toxicity of methotrexate (MTX) in patients with rheumatoid arthritis (RA).

METHOD

To identify relevant publications, we searched the Medline, Embase, Cochrane, and Web of Science databases. We performed a meta-analysis of studies on the relationship between the ATIC 347 C/G polymorphism and MTX toxicity or non-responsiveness in patients with RA.

RESULTS

Thirteen studies consisting of 3,185 patients with RA satisfied our inclusion criteria. The analysis included 10 studies on MTX responsiveness and seven studies on MTX toxicity in patients with RA in connection with ATIC 347C/G polymorphism. According to our meta-analysis, the ATIC 347 GG genotype and failure to respond to MTX treatment were significantly associated (OR = 0.741, 95% CI = 0.591-0.929, p=0.009). According to stratification by ethnicity, this genotype was significantly associated with non-responsiveness to MTX in Europeans (OR=0.548, 95% CI=0.377-0.796, p=0.002) but not in Asian populations (OR=0.882, 95% CI=0.665-1.1172, p=0.388). However, analyses employing allelic, dominant, and homozygous contrast models failed to detect any relationship between the polymorphism and the failure to respond to MXT. However, the ATIC 347GG genotype and MTX toxicity were not associated (OR=1.278, 95% CI=0.937-1.745, p=0.121). Asian and European populations showed no evidence of a relationship between the ATIC 347GG genotype and MTX toxicity (OR=1.252, 95% CI=0.905-1.732, p=0.175 and OR =1.617, 95% CI=0.549-4.765, p=0.383, respectively).

CONCLUSIONS

This meta-analysis revealed that ATIC 347 C/G polymorphism was related to non-responsiveness to MTX in European populations with RA. However, no significant correlation was found with MTX toxicity.

Role of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio as potential biomarkers in Behçet's disease: a meta-analysis

AIM

The mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) have attracted interest as possible indicators of inflammation and disease activity in various diseases. This meta-analysis assessed the association between NLR, MPV, PLR, and Behçet's disease (BD) and their correlation with disease activity and thrombosis.

METHODS

A thorough search of the Medline, Embase, and Cochrane databases was performed to identify relevant studies. Studies comparing NLR, MPV, and PLR between patients with BD and healthy controls, as well as studies examining these measures in connection with disease activity and thrombosis in BD satisfied the inclusion criteria. The standardized mean difference (SMD) and 95% confidence interval (CI) were used to calculate the effect sizes.

RESULTS

This meta-analysis included 24 articles. The findings revealed no discernible differences in MPV between the BD and control groups (p = 0.992). NLR was substantially higher in the BD group than in the control group (p < 0.001). PLR was higher in the BD group than in the control group (p = 0.030), indicating that BD is associated with a larger PLR. Patients with active and inactive BD did not vary significantly in terms of disease activity according to the MPV. Comparing MPV between patients with BD with and without thrombosis showed no discernible changes. However, individuals with active BD had a considerably higher NLR and PLR than those with inactive BD (p = 0.003 and p = 0.005, respectively). The statistical significance threshold for the association between NLR, PLR, and thrombosis in patients with BD was not met.

CONCLUSION

NLR and PLR can be regarded as general markers of inflammation according to the results of this meta-analysis.

Association between systemic sclerosis and venous thromboembolism, pulmonary embolism, and deep vein thrombosis: a meta-analysis

OBJECTIVE

This study aimed to analyze the published data pertaining to the correlation between venous thromboembolism (VTE) and systemic sclerosis (SSc).

METHODS

We conducted manual searches and explored MEDLINE, EMBASE, and Cochrane databases to review papers reporting the risk of VTE in patients with SSc. A meta-analysis was performed exploring the relative risks (RRs) of deep vein thrombosis (DVT), pulmonary embolism (PE), and VTE in these individuals.

RESULTS

Six trials that included 41,105 patients with SSc were eligible for inclusion. A meta-analysis of the six included studies revealed a statistically significant correlation (RR 2.372, 95% confidence interval [CI] = 1.608-3.500, p < 0.001) between the risk of VTE and SSc. Regional subgroup study revealed a strong correlation between SSc and VTE risk in Americans, Europeans, and Asians. Additionally, a significant correlation between SSc and PE risk was observed (RR 3.154, 95% CI = 1.320-7.539, p = 0.010). Finally, the meta-analysis revealed a substantial correlation (RR 5.190, 95% CI = 1.513-17.01, p = 0.009) between the risk of DVT and SSc.

CONCLUSION

This meta-analysis showed that SSc is linked to an increased risk of DVT, PE, and VTE. This finding underscores the importance of close monitoring for the emergence of these conditions in patients with SSc.

The role of NLRP3 and CARD8 polymorphisms in the risk of rheumatoid arthritis: A meta-analysis of genetic association studies

OBJECTIVE

To investigate the potential associations between rheumatoid arthritis (RA) and NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) rs35829419, rs10754558, s4612666, and caspase recruitment domain family member 8 (CARD8) rs2043211 polymorphisms.

METHODS

Relevant papers were searched for in MEDLINE, Embase, and Web of Science. Allele contrast, recessive, dominant, and homozygote contrast models were used to investigate the relationship between the NLRP3 rs35829419, rs10754558, and s4612666, and CARD8 rs2043211 polymorphisms and RA. This review was registered with PROSPERO (CRD42023451231).

RESULTS

The meta-analysis included 11 comparative studies comprising 3789 patients with RA and 3956 controls. No significant association was found between NLRP3 rs35829419 C allele and RA in Europeans, Arabs, or Latinos. The NLRP3 rs10754558 G allele was not associated with RA in the Asian or Arab populations. However, a single study in Latin America discovered a link between RA and the NLRP3 rs10754558 G allele. The NLRP3 rs4612666 T allele was not associated with RA, according to the meta-analysis. When ethnicity was stratified, there was no association between the NLRP3 rs4612666 T allele and RA, except for a single study that found an association among Arabs. The CARD8 rs2043211 T allele did not seem to be associated with RA. According to an ethnic stratification study, the CARD8 rs2043211 T allele did not appear to be associated with RA in Europeans, Arabs, or Latinos.

CONCLUSIONS

The meta-analysis indicated that the NLRP3 rs35829419, rs10754558, and s4612666 polymorphisms, as well as the CARD8 rs2043211 polymorphism, were not linked to RA susceptibility.

Treatment of active systemic lupus erythematosus with baricitinib: A meta-analysis of randomized controlled trials

OBJECTIVE

This study aimed to evaluate the safety and effectiveness of baricitinib in patients with systemic lupus erythematosus (SLE).

METHODS

We searched MEDLINE, EMBASE, and the Cochrane Controlled Trials Register to find relevant publications. Using data from randomized controlled trials (RCTs), we performed a meta-analysis to investigate the safety and efficacy of baricitinib in patients with active SLE who did not respond well to standard treatments.

RESULTS

A total of 1849 individuals (1235 experimental participants and 614 controls) from three RCTs on baricitinib were included. A reduction of ≥ 4 points from baseline in SLEDAI-2K score in the baricitinib 4 mg group was greater than the placebo group's reduction (odds ratio [OR] = 1.407, 95% confidence interval [CI] 1.123-1.763, p = .003). The baricitinib 4 mg group significantly outperformed the placebo group in terms of SLEDAI-2K remission of arthritis or rash (OR = 1.327, 95% CI = 1.059-1.663, p = .014). Other effectiveness outcomes such as the SRI4 response did not substantially improve in the baricitinib 4 mg group when compared with the placebo group. And there were no significant increase in the efficacy outcomes in the baricitinib 2 mg group than in the placebo group. However, there was a substantially higher incidence of severe adverse events (SAE) and serious infections in the baricitinib 4 mg group (OR = 1.493, 95% CI = 1.002-2.225, p = .049; OR = 2.303, 95% CI = 1.147-4.622, p = .019) compared to the placebo group. There were no differences between the baricitinib 2 mg and placebo groups in any of the safety outcome data.

CONCLUSION

Meta-analysis reveals that baricitinib 4 mg is beneficial for treating active SLE in terms of a reduction of ≥ 4 points from baseline in SLEDAI-2K score and SLEDAI-2K remission of arthritis or rash. However, the higher frequency of SAEs and serious infections was observed in the group receiving baricitinib 4 mg.

Associations between blood IL-33 levels and IL-33 gene polymorphisms with susceptibility to systemic lupus erythematosus: A meta-analysis

OBJECTIVES

This study investigated the relationship between circulating interleukin-33 (IL-33) levels and systemic lupus erythematosus (SLE) along with polymorphisms in the IL-33 gene and SLE susceptibility.

METHOD

The MEDLINE, EMBASE, and Cochrane Library databases (to May 2023) were searched for relevant publications. Using a meta-analysis we investigated serum/plasma IL-33 levels in patients with SLE and controls, and the relationship between IL-33 rs1929992, rs1891385, rs7044343, rs1095498, and rs10975579 polymorphisms and the risk of developing SLE.

RESULTS

Nine studies focusing on 1,935 patients with SLE were included. IL-33 levels were significantly higher in the SLE group than in the control group (SMD = 2.140, 95% CI = 1.068-3.212, p < .001). Asian, European, and Arab groups have shown increased IL-33 levels in SLE populations, according to ethnic stratification. Regardless of the sample size, variable adjustment, data format, or publication year, the subgroup analysis showed significantly higher IL-33 levels in the SLE group. This meta-analysis supported the significance of the link between SLE and the IL-33 rs1891385 C allele (OR, 1.525; 95% CI, 11.310-1.777; p = .010). A similar association was found between the IL-33 rs1891385 C/A polymorphism and SLE, using homozygote comparisons and dominant and recessive models. However, this meta-analysis found no association between the IL-33 polymorphisms rs1929992, rs7044343, rs1095498, and rs10975579 and susceptibility to SLE.

CONCLUSIONS

This meta-analysis identified significantly higher levels of circulating IL-33 in patients with SLE as well as an association between IL-33 rs1891385 and SLE.

Circulating leptin level in osteoarthritis and associations between leptin receptor polymorphisms and disease susceptibility: A meta-analysis

OBJECTIVE

This study aimed to systemically review the evidence on the relationship between the circulating leptin levels and osteoarthritis (OA), and the association between leptin and leptin receptor (LEPR) polymorphisms and OA susceptibility.

METHODS

To find relevant papers (up to February 2023) examining the association between circulating leptin levels, LEPR polymorphisms, and OA, the PUBMED, EMBASE, and Cochrane databases were searched. We performed a meta-analysis to examine the levels of synovial and serum/plasma leptin in OA patients compared with healthy controls, as well as the relationship between OA and LEPR polymorphisms.

RESULTS

Data from 15 investigations, totaling 2197 patients with OA and 2546 controls, were included in the meta-analysis. There were statistically significant differences in the levels of circulating leptin between the OA and control groups (standardized mean difference [SMD] 2.178, 95% confidence interval [CI] 1.208-3.139, P = 0.001). Leptin levels were also substantially greater in European, Asian, and Arab groups among OA patients. After adjusting for age, sex, and/or body mass index, the leptin levels of patients with OA were significantly higher. Similarly, regardless of sample size (n < 100 and n ≥ 100) or year of publication, leptin levels were considerably higher in the OA group. In addition, the synovial leptin level was greater in the OA group than in the control group (SMD 0.783; 95% CI 0.247-1.319, P = 0.004). In the LEPR rs1137101 polymorphism, the OA and AA genotypes were significantly associated (odds ratio 0.282, 95% CI 0.126-0.629, P = 0.002), according to the meta-analysis. Ethnic stratification revealed an association between OA and the LEPR rs1137101 AA genotype in Asian and Arab populations.

CONCLUSION

The results of this meta-analysis indicate that patients with OA had considerably greater levels of circulating leptin than did control individuals. In addition, synovial leptin levels were greater in OA patients than in healthy individuals, and the LEPR rs1137101 polymorphism was linked to an increased risk of developing OA. These results imply that leptin participates in the onset and progression of OA.