Resistin in serum is associated with higher levels of IL-1Ra in post-menopausal women with rheumatoid arthritis

Effects of intermittent fasting diet in overweight and obese postmenopausal women with rheumatoid arthritis: A randomized controlled clinical trial

BACKGROUND AND OBJECTIVE

Rheumatoid arthritis (RA), in the category of rheumatic diseases, is an autoimmune illness that affects joints and other parts of suffered patients. Intermittent fasting (IF) is a dietary pattern that has had beneficial impacts on several populations. This randomized controlled trial (RCT) hypothesized that IF can improve quality of life, clinical symptoms, inflammation, and oxidative stress in overweight and obese postmenopausal women with RA.

METHOD

This study was a controlled, parallel-group superiority design in which 44 overweight and obese postmenopausal women with RA were randomly allocated to receive either IF (n = 22) or the usual diet (n = 22) for 8 weeks. The intervention group received 16/8 IF, and the control group received the typical diet for 8 weeks. The primary outcome was the Health Assessment Questionnaire-Disability Index (HAQ-DI) questionnaire score. The secondary outcomes included body mass index (BMI) and morning joint stiffness (MS) and biochemical indicators, including serum concentrations of erythrocyte sedimentation rate (ESR), high sensitive c-reactive protein (hs-CRP), and total oxidant and antioxidant capacity (TOC and TAC), and oxidative stress index (OSI), and interleukin 6 (IL-6) were assessed at the baseline and end of the study. Disease severity was assessed using the Disease Activity Score-28 (DAS-28) and Clinical Disease Activity Index (CDAI).

RESULTS

The IF diet significantly improved BMI, DAS-28, CDAI, and HAQ (p-value<0.05 for all). However, there were no significant effects on the other study outcomes.

CONCLUSION

IF has beneficial effects on some outcomes related to RA patients, while it has no significant impact on inflammation and oxidative stress markers. More studies are needed to determine IF's effects on RA patients.

Effect of vitamin D on inflammatory and clinical outcomes in patients with rheumatoid arthritis: a systematic review and dose-response meta-analysis of randomized controlled trials

CONTEXT

Rheumatoid arthritis is a chronic inflammatory disease that causes synovitis. Vitamin D deficiency is common in rheumatoid arthritis.

OBJECTIVE

This systematic review and meta-analysis investigated whether vitamin D supplementation affects the inflammatory and clinical outcomes in patients with rheumatoid arthritis on the basis of randomized clinical trials.

DATA SOURCES

A literature search was performed in the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, MEDLINE, Embase, and Google Scholar for articles published until May 2022.

DATA EXTRACTION

The studies were selected according to PRISMA guidelines, and the risk of bias was assessed for randomized controlled trials.

DATA ANALYSIS

A random effects model was used to conduct a meta-analysis, and heterogeneity was assessed using the I2 statistic. Of 464 records, 11 studies were included from 3049 patients. Conclusion: Vitamin D supplementation did not significantly reduce C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), disease activity score in 28 joints (DAS28), or the health assessment questionnaire score; however, the response to supplementation was highly heterogeneous. The pooled analysis showed that vitamin D significantly reduced the pain-visual analogue scale (VAS) weighted mean difference (WMD = -1.30, 95% confidence interval [CI] [-2.34, -27], P = .01), DAS28-CRP (WMD = -.58, 95% CI [-.86, -.31], P < .0001), and DAS28-ESR (WMD = -.58, 95% CI [-.86, -.31], P = .0001). Subgroup analysis for vitamin D doses (>100 µg per day versus <100 µg per day) showed that the higher doses had a more significant effect on CRP than the lower doses (P < .05).

CONCLUSIONS

There was no significant difference between the effect of 2 vitamin D doses on ESR and DAS28. To minimize the high heterogeneity among studies in this meta-analysis, other confounding factors such as baseline vitamin D, age, dietary vitamin D, time of year, sun exposure, drug interaction, effect dosage, and power of study should be examined.

Adipokines in Rheumatoid Arthritis: Emerging Biomarkers and Therapeutic Targets

Rheumatoid arthritis (RA) is a chronic inflammatory disease manifested by joint involvement, extra-articular manifestations, and general symptoms. Adipose tissue, previously perceived as an inert energy storage organ, has been recognised as a significant contributor to RA pathophysiology. Adipokines modulate immune responses, inflammation, and metabolic pathways in RA. Although most adipokines have a pro-inflammatory and aggravating effect on RA, some could counteract this pathological process. The coexistence of RA and sarcopenic obesity (SO) has gained attention due to its impact on disease severity and outcomes. Sarcopenic obesity further contributes to the inflammatory milieu and metabolic disturbances. Recent research has highlighted the intricate crosstalk between adipose tissue and skeletal muscle, suggesting potential interactions between these tissues in RA. This review summarizes the roles of adipokines in RA, particularly in inflammation, immune modulation, and joint destruction. In addition, it explores the emerging role of adipomyokines, specifically irisin and myostatin, in the pathogenesis of RA and their potential as therapeutic targets. We discuss the therapeutic implications of targeting adipokines and adipomyokines in RA management and highlight the challenges and future directions for research in this field.

Effects of One-Year Tofacitinib Therapy on Lipids and Adipokines in Association with Vascular Pathophysiology in Rheumatoid Arthritis

Background: Cardiovascular (CV) morbidity, mortality and metabolic syndrome are associated with rheumatoid arthritis (RA). A recent trial has suggested increased risk of major CV events (MACE) upon the Janus kinase (JAK) inhibitor tofacitinib compared with anti-tumor necrosis factor α (TNF-α) therapy. In our study, we evaluated lipids and other metabolic markers in relation to vascular function and clinical markers in RA patients undergoing one-year tofacitinib therapy. Patients and methods: Thirty RA patients treated with either 5 mg or 10 mg bid tofacitinib were included in a 12-month follow-up study. Various lipids, paraoxonase (PON1), myeloperoxidase (MPO), thrombospondin-1 (TSP-1) and adipokine levels, such as adiponectin, leptin, resistin, adipsin and chemerin were determined. In order to assess flow-mediated vasodilation (FMD), common carotid intima-media thickness (IMT) and arterial pulse-wave velocity (PWV) ultrasonography were performed. Assessments were carried out at baseline, and 6 and 12 months after initiating treatment. Results: One-year tofacitinib therapy significantly increased TC, HDL, LDL, APOA, APOB, leptin, adipsin and TSP-1, while significantly decreasing Lp(a), chemerin, PON1 and MPO levels. TG, lipid indices (TC/HDL and LDL/HDL), adiponectin and resistin showed no significant changes. Numerous associations were found between lipids, adipokines, clinical markers and IMT, FMD and PWV (p < 0.05). Regression analysis suggested, among others, association of BMI with CRP and PWV (p < 0.05). Adipokines variably correlated with age, BMI, CRP, CCP, FMD, IMT and PWV, while MPO, PON1 and TSP-1 variably correlated with age, disease duration, BMI, RF and PWV (p < 0.05). Conclusions: JAK inhibition by tofacitinib exerts balanced effects on lipids and other metabolic markers in RA. Various correlations may exist between metabolic, clinical parameters and vascular pathophysiology during tofacitinib treatment. Complex assessment of lipids, metabolic factors together with clinical parameters and vascular pathophysiology may be utilized in clinical practice to determine and monitor the CV status of patients in relation with clinical response to JAK inhibition.

The Adipokine Network in Rheumatic Joint Diseases

Rheumatic diseases encompass a diverse group of chronic disorders that commonly affect musculoskeletal structures. Osteoarthritis (OA) and rheumatoid arthritis (RA) are the two most common, leading to considerable functional limitations and irreversible disability when patients are unsuccessfully treated. Although the specific causes of many rheumatic conditions remain unknown, it is generally accepted that immune mechanisms and/or uncontrolled inflammatory responses are involved in their etiology and symptomatology. In this regard, the bidirectional communication between neuroendocrine and immune system has been demonstrated to provide a homeostatic network that is involved in several pathological conditions. Adipokines represent a wide variety of bioactive, immune and inflammatory mediators mainly released by adipocytes that act as signal molecules in the neuroendocrine-immune interactions. Adipokines can also be synthesized by synoviocytes, osteoclasts, osteoblasts, chondrocytes and inflammatory cells in the joint microenvironment, showing potent modulatory properties on different effector cells in OA and RA pathogenesis. Effects of adiponectin, leptin, resistin and visfatin on local and systemic inflammation are broadly described. However, more recently, other adipokines, such as progranulin, chemerin, lipocalin-2, vaspin, omentin-1 and nesfatin, have been recognized to display immunomodulatory actions in rheumatic diseases. This review highlights the latest relevant findings on the role of the adipokine network in the pathophysiology of OA and RA.

Associations between Adipokines in Arthritic Disease and Implications for Obesity

Secretion from adipose tissue of adipokines or adipocytokines, comprising of bioactive peptides or proteins, immune molecules and inflammatory mediators, exert critical roles in inflammatory arthritis and obesity. This review considers the evidence generated over the last decade regarding the effects of several adipokines including leptin, adiponectin, visfatin, resistin, chemerin and apelin, in cartilage and bone homeostasis in the pathogenesis of rheumatoid arthritis and osteoarthritis, which has important implications for obesity.

Enhancement of immune response mediated by oropharyngeal colostrum administration in preterm neonates

BACKGROUND

The immune system of preterm infants is immature, being a significant cause of morbidity and mortality, particularly in the preterm infant. Oropharyngeal colostrum administration could be an immunomodulatory aid. Our aim was to evaluate the effect of oropharyngeal colostrum on the serum levels of immunoglobulins, lactoferrin, and resistin during the first month of life and to track the clinical outcome of the neonates.

METHODS

One hundred preterm neonates born at <32 weeks of gestation and/or weighing < 1500 g and assisted in the Neonatal Intensive Care Unit were enrolled and divided into two groups: colostrum (n = 48) and control (n = 52). The subjects assigned to the colostrum group received 0.2 mL of colostrum (oropharyngeal route) every 4 hours for the first 15 days of life, and if mothers have inability to breastfeed, they were included in the control group (no oropharyngeal colostrum). Serum concentrations of IgA, IgM, and IgG1, lactoferrin, and resistin were assessed in both groups at 1, 3, 15, and 30 days of life. Clinical data during hospitalization were collected.

RESULTS

IgA and IgM increased in preterm neonates who were administered colostrum for 15 and 30 days. Lactoferrin increased after 30 days, and resistin increased after 15 days of supplying oropharyngeal colostrum. The colostrum group underwent full enteral nutrition before, and no differences were observed in the common neonatal morbidities.

CONCLUSION

Oropharyngeal colostrum administration is safe in preterm neonates and improves their immunologic profile, showing a potential role as an immunomodulatory agent.

Carnosine Supplementation Improves Serum Resistin Concentrations in Overweight or Obese Otherwise Healthy Adults: A Pilot Randomized Trial

Adipokines play an important role in the regulation of glucose metabolism. We have previously shown that carnosine supplementation in overweight or obese non-diabetic individuals improves glucose metabolism but does not change adiponectin concentrations. However, its effect on other adipokines has not been investigated. Herein we further determined the effect of carnosine supplementation on serum adipsin, resistin and leptin. Twenty-two overweight or obese otherwise healthy adults were randomly assigned to receive either 2 g of carnosine (n = 13) or identically looking placebo (n = 9) for 12 weeks. Serum adipsin, leptin and resistin were analyzed using a bead-based multiplex assay. Carnosine supplementation decreased serum resistin concentrations compared to placebo (mean change from baseline: −35 ± 83 carnosine vs. 35 ± 55 ng/mL placebo, p = 0.04). There was a trend for a reduction in serum leptin concentrations after carnosine supplementation (−76 ± 165 ng/mL carnosine vs. 20 ± 28 ng/mL placebo, p = 0.06). The changes in leptin and resistin concentrations were inversely related to the change in concentration for urinary carnosine (r = −0.72, p = 0.0002; r = −0.67, p = 0.0009, respectively), carnosine-propanal (r = −0.56, p = 0.005; r = −0.63, p = 0.001, respectively) and carnosine-propanol (r = −0.61, p = 0.002; r = −0.60, p = 0.002, respectively). There were no differences between groups in change in adipsin concentrations. Our findings show carnosine supplementation may normalize some, but not all, of the serum adipokine concentrations involved in glucose metabolism, in overweight and obese individuals. Further clinical trials with larger samples are needed to confirm these results.

Impact of obesity on autoimmune arthritis and its cardiovascular complications

Obesity can instigate and sustain a systemic low-grade inflammatory environment that can amplify autoimmune disorders and their associated comorbidities. Metabolic changes and inflammatory factors produced by the adipose tissue have been reported to aggravate autoimmunity and predispose the patient to cardiovascular disease (CVD) and metabolic comorbidities. Rheumatoid arthritis (RA) and psoriatic arthritis (PsA) are autoimmune arthritic diseases, often linked with altered body mass index (BMI). Severe joint inflammation and bone destruction have a debilitating impact on the patient's life; there is also a staggering risk of cardiovascular morbidity and mortality. Furthermore, these patients are at risk of developing metabolic symptoms, including insulin resistance resulting in type 2 diabetes mellitus (T2DM). In addition, arthritis severity, progression and response to therapy can be markedly affected by the patient's BMI. Hence, a complex integrative pathogenesis interconnects autoimmunity with metabolic and cardiovascular disorders. This review aims to shed light on the network that connects obesity with RA, PsA, systemic lupus erythematosus and Sjӧgren's syndrome. We have focused on clarifying the mechanism by which obesity affects different cell types, inflammatory factors and traditional therapies in these autoimmune disorders. We conclude that to further optimize arthritis therapy and to prevent CVD, it is imperative to uncover the intricate relation between obesity and arthritis pathology.

Inflammation, obesity and rheumatic disease: common mechanistic links. A narrative review

Obesity represents a rising global health concern, linked to significant social, psychological and physical burden to the individual affected, people around them and the society as a whole. Obesity has been described as a low-grade inflammatory condition, associated with increased production of pro-inflammatory mediators like tumor necrosis factor alpha or interleukin 6 and altered expression of adipokines. Adipokines, mainly produced by adipose tissue, have mixed pro- and anti-inflammatory properties. Obesity rarely exists on its own; instead, it tends to coexist with (often multiple) other comorbidities, including metabolic, cardiovascular, and rheumatic and musculoskeletal diseases (RMDs). In the case of RMDs, evidence is rapidly accumulating on common mechanistic pathways implicated in the inflammatory states seen between RMDs and obesity. Although there remain unanswered questions on the exact mechanisms of inflammation that link obesity to RMDs, what is becoming increasingly known is the association between obesity and adverse clinical outcomes in RMDs. This narrative review discusses insights into mechanisms of inflammation linking obesity and RMDs and evidence on the impact of obesity on treatment response and important disease outcomes. We highlight the importance of targeting obesity, a common and modifiable comorbidity, as part of the routine care of people with RMDs.

Chronic Pain in Inflammatory Arthritis: Mechanisms, Metrology, and Emerging Targets-A Focus on the JAK-STAT Pathway

Chronic pain is nowadays considered not only the mainstay symptom of rheumatic diseases but also "a disease itself." Pain is a multidimensional phenomenon, and in inflammatory arthritis, it derives from multiple mechanisms, involving both synovitis (release of a great number of cytokines) and peripheral and central pain-processing mechanisms (sensitization). In the last years, the JAK-STAT pathway has been recognized as a pivotal component both in the inflammatory process and in pain amplification in the central nervous system. This paper provides a summary on pain in inflammatory arthritis, from pathogenesis to clinimetric instruments and treatment, with a focus on the JAK-STAT pathway.

Resistin as an inflammatory marker in patients with schizophrenia treated with clozapine

BACKGROUND

Schizophrenia is associated with excess cardiovascular comorbidity and mortality related to lifestyle factors, such as lack of physical activity, poor diet, and smoking. The prevalence of metabolic syndrome is increased among patients with schizophrenia, with the highest rates among patients on clozapine treatment. Smoking, obesity, physical inactivity, airway inflammation and obstruction, and adipose tissue and inflammatory marker activation are related in systemic inflammation. Low-grade inflammation is also associated with schizophrenia. Adipokine resistin is a biomarker involving several acute and chronic inflammatory states. However, the inflammatory role of resistin is so far inconclusive and studies in schizophrenia are scanty.

AIMS

The aim of the present study was to explore the role of serum resistin as an inflammatory marker in patients with schizophrenia on clozapine treatment.

METHODS

Associations between serum levels of resistin and some other selected cytokines/adipokines (adiponectin, leptin, adipsin, IL-6, IL-1Ra, TNF-α, hs-CRP) and metabolic markers in 190 patients with schizophrenia on clozapine treatment were studied using a cross-sectional study design.

RESULTS

Among male patients especially, smokers had higher levels of resistin than non-smokers, and among smokers resistin levels were associated with IL-1Ra and hs-CRP levels. In the whole patient group levels of resistin associated with levels of IL-1Ra, and among male patients with low HDL-cholesterol.

CONCLUSIONS

Resistin is a biomarker of systemic inflammation associated with smoking among patients with schizophrenia on clozapine treatment. Resistin might have a role as a marker of cardiovascular comorbidity.

Increased resistin levels in the serum and cerebrospinal fluid of patients with neuromyelitis optica

INTRODUCTION

Resistin, which acts as a pro-inflammatory cytokine, has been implicated in the pathogenesis of several autoimmune diseases. However, the involvement of resistin in neuromyelitis optica (NMO), a severe inflammatory central nervous system disorder that targets the optic nerve and spinal cord, remains unclear.

METHODS

We measured serum and cerebrospinal fluid (CSF) resistin levels in patients with NMO and controls matched by age and sex. The link between resistin levels and clinical variables in NMO was subsequently assessed.

RESULTS

The concentrations of serum and CSF resistin were significantly higher in patients with NMO than in controls, and decreased following treatment with methylprednisolone. High sensitivity C-reactive protein (hs-CRP) levels and annualized relapse rate positively correlated with resistin levels in patients with NMO.

CONCLUSION

Resistin might be a useful biomarker of inflammation in NMO, and a potential target for the treatment of NMO.

Peripheral blood leptin and resistin levels as clinical activity biomarkers in Mexican Rheumatoid Arthritis patients

OBJECTIVE

To evaluate the association between the clinical activity of RA patients and serum adipocytokines (Leptin, Adiponectin and Resistin) and inflammatory cytokines.

METHODS

All RA patients fulfilled ACR 1987 criteria and were treated with DMARDs. Adipocytokine and inflammatory cytokine levels were evaluated using ELISA.

RESULTS

121 patients were included in the study. Stratifying according to DAS28 (low, moderate and high activity), there were significant differences for Leptin, Resistin, IL-6 and IL-17, however, no differences were seen for Adiponectin, TNFα or IL-1β. Clinical activity positively correlated with Leptin, Resistin, IL-17 and IL-6 levels, but not with Adiponectin, TNFα or IL-1β. Adiponectin levels negatively correlated with TNFα and positively correlated with IL-1β. IL-1β positively correlated with IL-6 and negatively correlated with TNFα and IL-17.

CONCLUSION

Circulating Leptin, Resistin, IL-6 and IL-17 levels positively correlate with RA clinical activity in a manner independent of the subject's BMI. Complex relationships between inflammatory cytokines were observed in RA patients suggesting that other metabolic or inflammatory factors could be involved.

Human adipose-derived mesenchymal stem cells attenuate collagen antibody-induced autoimmune arthritis by inducing expression of FCGIIB receptors

Background

Adipose-derived stem cells (ASCs) are mesenchymal stem cells (MSCs) derived from adipose tissue. MSCs have multiple properties including anti-inflammatory and immunomodulatory effects in various disease models and human diseases. However, the mechanisms underlying this wide range of effects need to be explored.

Methods

Collagen antibody-induced arthritis (CAIA) is a unique model in which arthritis is rapidly and strongly induced. ASCs were intraperitoneally infused into CAIA mice before or after arthritis induction. The serum levels of various cytokines, adipokines, and chemokines were measured. The expression of FC gamma receptors (FCGRs) was investigated in peritoneal macrophages ex vivo. RAW264.7 cells and ASCs were co-cultured to elucidate the direct and indirect role of ASCs on FCGR expression.

Results

ASCs attenuated arthritis in CAIA mice. Serum levels of tumor necrosis factor α, interleukin (IL)-15, resistin, and leptin were reduced in ASC-treated CAIA mice, whereas serum levels of IL-6 and adiponectin were not affected. In peritoneal macrophages isolated from ASC-treated mice, expression of FCGRIIB, which is immunoinhibitory, was higher than that of FCGRI. Co-culture of ASCs with RAW264.7 cells modulated the expression of FCGRs. The expression patterns and timings of peak expression differed among FCGRs. Expression of FCGRIIB was higher and peaked earlier than that of FCGRI. FCGRIII expression was not affected by this co-culture.

Conclusions

This is a study to show that ASCs have anti-arthritic effects in CAIA mice. Modulation of FCGRs by ASCs might be a therapeutic mechanism in this antibody-associated arthritis model.

Resistin in inflammatory and degenerative rheumatologic diseases. Relationship between resistin and rheumatoid arthritis disease progression

AIMS OF THE STUDY

To assess and compare resistin levels in the serum and synovial fluid of patients with rheumatoid arthritis (RA; an inflammatory rheumatologic disease) and osteoarthritis (OA; a degenerative rheumatologic disease) and to study the relationship between resistin levels and prognostic factors of RA disease progression.

PATIENTS AND METHODS

This study included a total of 50 patients: 25 with RA and 25 with OA. Full case history was documented for all patients and all underwent a thorough clinical examination and laboratory testing. Body mass index (BMI) values were also calculated. Radiographs were made of OA patients' knees and RA patients' hands. Disease Activity Score 28 (DAS28) was calculated for RA patients. Serum and synovial fluid samples were obtained from the effused knees of all patients and tested for resistin level.

RESULTS

Serum resistin levels were higher in RA patients than in those with OA (p < 0.01). Synovial fluid resistin levels were also higher in RA than OA patients (p < 0.001). While serum resistin levels correlated with Larsen score and total leukocyte count (TLC), synovial fluid resistin levels correlated with rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) levels in addition to Larsen score and TLC.

CONCLUSION

Resistin levels were found to be higher in the serum and synovial fluid of RA patients than in those with OA. This may suggest a role for resistin in inflammatory rheumatologic diseases. The observed statistically significant correlation between synovial fluid resistin levels and RF, ACPA and Larsen score may suggest that high synovial fluid resistin levels can be considered a poor prognostic factor for RA progression. However, further studies employing a larger cohort of patients are needed to confirm the relevance of resistin as a prognostic marker in RA patients.

Adipokines as potential biomarkers in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic systemic inflammatory autoimmune disease characterized by severe joint injury. Recently, research has been focusing on the possible identification of predictor markers of disease onset and/or progression, of joint damage, and of therapeutic response. Recent findings have uncovered the role of white adipose tissue as a pleiotropic organ not only specialized in endocrine functions but also able to control multiple physiopathological processes, including inflammation. Adipokines are a family of soluble mediators secreted by white adipose tissue endowed with a wide spectrum of actions. This review will focus on the recent advances on the role of the adipokine network in the pathogenesis of RA. A particular attention will be devoted to the action of these proteins on RA effector cells, and on the possibility to use circulating levels of adipokines as potential biomarkers of disease activity and therapeutic response.

The role of resistin in inflammatory myopathies

Both immune and non-immune mechanisms are involved in muscle damage and dysfunction occurring in idiopathic inflammatory myopathies (IIMs). Crosstalk among inflammatory cells, muscle and endothelial cells is essential in the pathogenesis of IIMs. Resistin, originally described as an adipokine linking obesity and insulin resistance in rodents, has been shown a pro-inflammatory molecule in humans. Besides its direct effect on production of several inflammatory mediators, resistin influences chemotaxis, migration, proliferation, cell survival, endothelial dysfunction and metabolism--all aspects implicated in the pathogenesis of IIMs. Up-regulation of resistin in muscle tissue and elevated serum resistin levels have been recently demonstrated in patients with IIMs. In addition, serum levels of resistin reflected global disease activity, including extramuscular organ involvement, in patients with this disease. However, there are currently not sufficient data to distinguish the features of resistin that cause injury of muscle tissue from those that promote muscle regeneration and repair. The aim of this review is therefore to summarize current knowledge about potential implication of resistin in idiopathic inflammatory myopathies.

A study of the link between bone turnover markers and bone mineral density with inflammation and body mass in postmenopausal women with active rheumatoid arthritis

In this study, the levels of bone turnover markers (BTMs) and bone mineral density (BMD) were studied in relation to body mass and several inflammatory markers, in postmenopausal patients with rheumatoid arthritis (RA). Fifty-nine postmenopausal women with active RA (lean, overweight, obese) were studied. The femoral BMD and serum levels of BTMs: osteocalcin (OC) and collagen type I cross-linked C-telopeptide fragments (CTX), and osteopontin (OPN), resistin, high sensitivity C-reactive protein, interleukin-6, tumor necrosis factor (TNF)-α in these patients were measured. It has been noticed that obese women had significantly higher total femoral BMD and total T-score compared to the lean subjects (p ≤ 0.01). The significant associations of BMD measures and CTX levels with body mass parameters (p ≤ 0.01 and p < 0.05, respectively) were found. Values of neck BMD adjusted for BMI were inversely associated with concentrations of TNF-α (p < 0.05). Osteocalcin levels inversely correlated with resistin (p ≤ 0.01) and CTX levels positively correlated with OPN (p ≤ 0.01). There were found no associations between BTMs and BMD with other inflammatory indices. Inverse correlations between OPN levels and body mass (p < 0.05), waist circumference (p < 0.05), and duration of postmenopausal period (p ≤ 0.01) were observed. Findings of the present study suggest that body mass and inflammatory markers, most of all OPN, resistin and TNF-α, play an important role in bone metabolism in postmenopausal women with active RA.

Temporal relationship between serum adipokines, biomarkers of bone and cartilage turnover, and cartilage volume loss in a population with clinical knee osteoarthritis

OBJECTIVE

The association of obesity with both hand and knee osteoarthritis (OA) is suggestive of a link between dysfunctional metabolism and joint integrity. Given the role of adipokines in mediating bone and cartilage homeostasis, we undertook this study to examine the relationship between adipokines and bone and cartilage biomarkers in a population of subjects with OA, and to determine whether adipokine levels predicted 2-year cartilage integrity.

METHODS

One hundred seventeen subjects underwent magnetic resonance imaging at baseline and at 2-year followup. Cartilage volume was assessed from these images. Serum adipokine levels were measured at baseline. Bone and cartilage biomarker levels were measured at baseline and at 2-year followup. Linear regression was used to examine the relationship between baseline levels of adipokines and adipokine receptors (leptin, soluble leptin receptor [sOB-Rb], resistin, and adiponectin) and changes in levels of bone biomarkers (osteocalcin, N-terminal type I procollagen propeptide [PINP], C-terminal crosslinking telopeptide of type I collagen, N-terminal crosslinking telopeptide of type I collagen, or C-terminal crosslinking telopeptide of type I collagen generated by matrix metalloproteinases), levels of cartilage biomarkers (cartilage oligomeric matrix protein, N-terminal type IIA procollagen propeptide [PIIANP], or C2C), cartilage defects score, and cartilage volume over 2 years.

RESULTS

Baseline leptin was associated with increased levels of bone formation biomarkers (osteocalcin and PINP) over 2 years, while sOB-Rb was associated with reduced levels of osteocalcin. Baseline sOB-Rb was associated with reduced levels of the cartilage formation biomarker PIIANP, an increased cartilage defects score, and increased cartilage volume loss over 2 years. All results were independent of age, sex, and body mass index.

CONCLUSION

The findings of this study support the concept that serum adipokines may provide a nonmechanical link between obesity and joint integrity (which may be mediated by bone and cartilage turnover) that subsequently results in changes to the cartilage defects score and cartilage volume loss. This may facilitate our understanding of the mechanisms by which obesity is involved in the pathogenesis of OA.

Adipokines in psoriatic arthritis patients: the correlations with osteoclast precursors and bone erosions

Significant bone remodeling with disordered osteoclastogenesis has been implicated in the pathogenesis of psoriatic arthritis (PsA). And there is a high prevalence of the metabolic syndrome (MS) in PsA patients. Adipokines, especially leptin and adiponectin, have recently been reported to be involved in the development and regulation of some autoimmune diseases. In this study, we examined the alternation of circulating osteoclastogenesis related cytokines [tumor necrosis factor-α (TNF-α), osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL)] and adipokines (leptin, adiponectin, resistin, chemerin, omentin) in PsA patients, and analysed the correlations between these factors and osteoclast precursors numbers, radiographic damage scores, and disease activity index. 41 PsA patients, 20 psoriasis patients, and 24 healthy controls were recruited. Blood samples were obtained for detecting the levels of TNF-α, OPG, RANKL and the adipokines. The numbers of osteoclast precursors (OCs) in peripheral blood were assessed. Radiographs of affected joints in PsA patients were scored for erosion, joint-space narrowing, osteolysis, and new bone formation. Compared with healthy controls, patients with PsA had higher TNF-α, RANKL, OCs, leptin and omentin but lower adiponectin and chemerin. Increased serum levels of TNF-α, RANKL, leptin, and omentin were positively correlated with OCs numbers. In contrast, serum adiponectin levels were decreased in PsA patients and negatively correlated with OCs numbers. TNF-α, RANKL and leptin were positively correlated with Psoriatic Arthritis Joint Activity Index (PsAJAI). Only TNF-α was positively correlated with radiographic damage scores. Our data demonstrated that systemic expression of soluble mediators of osteoclastogenesis and adipokines were disordered in PsA. Certain adipokines were elevated in the circulation of patients with PsA and might contribute to pathogenesis of arthritis. Prospective studies will be of interest to determine the pluripotent effects of adipokines on osteoclastogenesis in chronic inflammatory rheumatic diseases. Future studies may lead to novel therapeutic strategies.

Treatment-specific changes in circulating adipocytokines: a comparison between tumour necrosis factor blockade and glucocorticoid treatment for rheumatoid arthritis

OBJECTIVE

There is increasing evidence that adipocytokines may exert proinflammatory and destructive effects in rheumatoid arthritis (RA). Hence, the authors investigated the relationship between adipocytokines and several features associated with RA (inflammation, joint destruction and cardiovascular disease), as well as the effect of treatment with a tumour necrosis factor inhibitor or glucocorticoids (GCs) hereupon.

METHODS

Serum levels of adiponectin, leptin, resistin, visfatin, vaspin and lipids were determined in a well-defined cohort of patients with RA before and after 16 weeks of adalimumab treatment (adalimumab cohort). The same parameters were analysed in two other cohorts of patients with RA before and after 2 weeks of high-dose prednisolone (high GC cohort) and before and after 22 weeks of treatment with a combination regimen with tapered high-dose prednisolone (COBRA -GC cohort). Radiographs of hands and feet (adalimumab and COBRA-GC cohorts) were assessed at baseline and after treatment.

RESULTS

Treatment with adalimumab or GC showed opposing effects on vaspin and visfatin levels. Lipid levels improved after several months of adalimumab or GC treatment; in the adalimumab cohort, this was related to reduced visfatin levels, independent of C reactive protein levels. After long-term adalimumab or GC treatment, resistin levels declined, which was associated with a decrease in inflammation markers. In the adalimumab cohort, baseline resistin levels were predictive of baseline radiological damage, independent of anticitrullinated peptide antibodies status or C reactive protein levels.

CONCLUSION

Changes in serum adipocytokine levels were treatment specific, further strengthening the role of visfatin and resistin in several disease manifestations of RA.

Role of adipokines in atherosclerosis: interferences with cardiovascular complications in rheumatic diseases

Patients with rheumatic diseases have an increased risk of mortality by cardiovascular events. In fact, several rheumatic diseases such as rheumatoid arthritis, osteoarthritis, systemic lupus erythematosus, and ankylosing spondylitis are associated with a higher prevalence of cardiovascular diseases (CVDs). Although traditional cardiovascular risk factors have been involved in the pathogenesis of cardiovascular diseases in rheumatic patients, these alterations do not completely explain the enhanced cardiovascular risk in this population. Obesity and its pathologic alteration of fat mass and dysfunction, due to an altered pattern of secretion of proinflammatory adipokines, could be one of the links between cardiovascular and rheumatic diseases. Indeed, the incidence of CVDs is augmented in obese individuals with rheumatic disorders. Thus, in this paper we explore in detail the relationships among adipokines, rheumatic diseases, and cardiovascular complications by giving to the reader a holistic vision and several suggestions for future perspectives and potential clinical implications.

The role of adipokines in connective tissue diseases

Objective

To discuss the relationship between adipokines and connective tissue diseases, by putting special emphasis on the potential role of leptin, adiponectin, resistin, and other adipose tissue products in the pathogenesis of rheumatoid arthritis and systemic lupus erythematosus and on possible application of adipokine-targeted therapy in the treatment of these disorders with emphasis on the recent findings.

Methods

PubMed literature search complemented by review of bibliographies listed in identified articles.

Results

Most of the data presented by different research groups showed changed levels of leptin, adiponectin, and resistin and occasionally also other adpokines in rheumatoid arthritis and systemic lupus erythematosus. The relationship between the remaining connective tissue diseases and adipokines is less documented.

Conclusions

Plasma levels of adipokines might tell us too little about their role in connective tissue disorders, whereas adipokine effects on synovial tissues might differ from their known metabolic or cardiovascular effects, which implies that some re-appraisal of adipokines role may need to take place. It still remains obscure whether the observed disturbances in various adipokine systems in subjects with connective tissue diseases contribute to their development or only reflect the presence or activity of inflammatory process, which itself is induced by other pro-inflammatory factors.

[Serum and synovial adiponectin, resistin, and visfatin levels in rheumatoid arthritis patients. Relation to disease activity]

BACKGROUND

Recent data provided evidence on the implication of the adipocytokines adiponectin, visfatin, and resistin in inflammation, immune response, and tissue destruction and revealed several links between them and arthritis.

AIM OF THE STUDY

The purpose of this study was to assess the levels of adiponectin, visfatin, and resistin in serum and synovial fluid of patients with rheumatoid arthritis (RA) and their relationship with disease activity.

SUBJECTS AND METHODS

A total of 70 female patients with RA and 30 age- and sex-matched healthy controls were enrolled. The clinical activity of RA patients was assessed according to the 28 joint count Disease Activity Score and patients were classified into two groups: 39 patients with active disease (group A) and 31 patients in remission (group B). Synovial fluid was obtained by arthrocentesis of the affected knee joints from 39 patients with active disease. Serum adiponectin, visfatin, and resistin concentrations were measured in RA patients and controls, while a specific enzyme-linked immunosorbent assay was used to measure the synovial concentrations of adiponectin, visfatin, and resistin in the group of patients with active RA.

RESULTS

Serum levels of adiponectin and visfatin were significantly higher in all RA patients and patients with active disease compared to the control group and patients in remission. No significant difference was observed in the resistin level between patients and controls. Serum and synovial adiponectin and visfatin were positively correlated with DAS28-ESR in RA patients with active disease.

CONCLUSION

Our data demonstrated that adiponectin and visfatin are related to disease activity in RA patients and might be involved in the progression of RA. The English full-text version of this article is available at SpringerLink (under "Supplemental").

Interactions between Serum Adipokines and Osteocalcin in Older Patients with Hip Fracture

Introduction. Experiments on genetically modified animals have discovered a complex cross-regulation between adipokines (leptin, adiponectin) and osteocalcin. The relationships between these molecules in human osteoporosis are still unclear. We evaluated the hypothesis of a bidirectional link between adipokines and osteocalcin. Materials and Methods. In a cross-sectional study of 294 older patients with osteoporotic hip fracture, we estimated serum concentrations of leptin, adiponectin, resistin, osteocalcin, parameters of mineral metabolism, and renal function. Results. After adjustment for multiple potential confounders, serum osteocalcin concentration was inversely associated with resistin and positively with leptin, leptin/resistin ratio, and adiponectin/resistin ratio. In multivariate regression models, osteocalcin was an independent predictor of serum leptin, resistin, leptin/resistin, and adiponectin/resistin ratios. Conclusions. Our data support the bidirectional regulation between osteocalcin and adipokines, but contrary to the genetically modified animal models, in older subjects with osteoporotic hip fracture, serum osteocalcin is positively associated with leptin and inversely with resistin.

Adipokines: biofactors from white adipose tissue. A complex hub among inflammation, metabolism, and immunity

Until the identification of leptin, the first adipokine discovered in 1994, adipose tissue was considered only as an energy storage tissue. However, it is now clear that adipose tissue is an endocrine/paracrine/autocrine organ, which plays a relevant role in physiopathology of several inflammatory diseases. Actually, it is mainly involved not only in the low-grade inflammatory status in obesity but also in other relevant inflammatory conditions and autoimmune disorders. In this review article, we discuss the main biological activities of leptin, adiponectin, lipocalin-2, resistin, and visfatin, as well as their contributions to certain inflammatory conditions.

Beyond fat mass: exploring the role of adipokines in rheumatic diseases

The cloning of leptin in 1994 by Zhang et al. introduced a novel concept about white adipose tissue (WAT) as a very dynamic organ that releases a plethora of immune and inflammatory mediators, such as adipokines and cytokines, which are involved in multiple diseases. Actually, adipokines exert potent modulatory actions on target tissues involved in rheumatic diseases including cartilage, synovial, bone and immune cells. The goal of this paper is to elucidate the recent findings concerning the involvement of adipokines in rheumatic diseases, such as rheumatoid arthritis (RA), osteoarthritis (OA), and systemic lupus erythematosus (SLE).

What's new in our understanding of the role of adipokines in rheumatic diseases?

Important advances in our understanding of the relationships between adipokines, inflammation and the immune response have been achieved in the past 10 years. White adipose tissue has emerged as a highly dynamic organ that releases a plethora of immune and inflammatory mediators that are involved in numerous diseases, including not only rheumatic diseases such as rheumatoid arthritis, osteoarthritis and systemic lupus erythematosus, but also cardiovascular and metabolic complications that are frequently observed in rheumatic diseases. Our rapidly growing knowledge of adipokine biology is revealing the complexity of these amazing proteins, thereby redefining white adipose tissue as a key element of the inflammatory and immune response in rheumatic diseases. Adipokines exert potent modulatory actions on target tissues and cells involved in rheumatic disease, including cartilage, synovium, bone and various immune cells. In this Review, we describe the most recent advances in adipokine research in the context of rheumatic diseases, focusing primarily on leptin, adiponectin, visfatin and resistin, and also the potential role of newly identified adipokines such as chemerin, lipocalin 2 and serum amyloid A3.

Resistin decreases expression of endothelial nitric oxide synthase through oxidative stress in human coronary artery endothelial cells

Resistin is a newly discovered adipocyte-derived cytokine that may play an important role in insulin resistance, diabetes, adipogenesis, inflammation, and cardiovascular disease. However, it is largely unknown whether resistin impairs endothelial functions by affecting the endothelial nitric oxide synthase (eNOS) system. In this study, we determined the effect of human recombinant resistin protein on eNOS expression and regulation in human coronary artery endothelial cells (HCAECs). When cells were treated with clinically relevant concentrations of resistin (40 or 80 ng/ml) for 24 h, the levels of eNOS mRNA, protein, and activity and eNOS mRNA stability were significantly reduced. Cellular nitric oxide levels were also decreased. In addition, the cellular levels of reactive oxygen species (ROS), including superoxide anion, were significantly increased in resistin-treated HCAECs. Mitochondrial membrane potential and the activities of catalase and superoxide dismutase were reduced. Three antioxidants, seleno-L-methionine, ginsenoside Rb1, and MnTBAP (superoxide dismutase mimetic), effectively blocked resistin-induced eNOS downregulation. Meanwhile, resistin activated the mitogen-activated protein kinases p38 and c-Jun NH(2)-terminal kinase (JNK), and the specific p38 inhibitor SB-239063 effectively blocked resistin-induced ROS production and eNOS downregulation. Furthermore, immunoreactivity of resistin was increased in atherosclerotic regions of human aorta and carotid arteries. Thus resistin directly induces eNOS downregulation through overproduction of ROS and activation of p38 and JNK in HCAECs. Resistin-induced mitochondrial dysfunction and imbalance in cellular redox enzymes may be the underlying mechanisms of oxidative stress.

The role of resistin as a regulator of inflammation: Implications for various human pathologies

Resistin was originally described as an adipocyte-secreted peptide that induced insulin resistance in rodents. Increasing evidence indicates its important regulatory roles in various biological processes, including several inflammatory diseases. Further studies have shown that resistin in humans, in contrast to its production by adipocytes in mice, is synthesized predominantly by mononuclear cells both within and outside adipose tissue. Possible roles for resistin in obesity-related subclinical inflammation, atherosclerosis and cardiovascular disease, non-alcoholic fatty liver disease, rheumatic diseases, malignant tumors, asthma, inflammatory bowel disease, and chronic kidney disease have already been demonstrated. In addition, resistin can modulate several molecular pathways involved in metabolic, inflammatory, and autoimmune diseases. In this review, current knowledge about the functions and pathophysiological implications of resistin in different human pathologies is summarized, although there is a significant lack of firm evidence regarding the specific role resistin plays in the "orchestra" of the numerous mediators of inflammation.

Adipocytokines are associated with radiographic joint damage in rheumatoid arthritis

OBJECTIVE

Obesity protects against radiographic joint damage in rheumatoid arthritis (RA) through poorly defined mechanisms. Adipocytokines are produced in adipose tissue and modulate inflammatory responses and radiographic joint damage in animal models. The purpose of this study was to examine the hypothesis that adipocytokines modulate inflammation and radiographic joint damage in patients with RA.

METHODS

We compared serum concentrations of leptin, resistin, adiponectin, and visfatin in 167 RA patients and 91 control subjects. The independent association between adipocytokines and body mass index (BMI), measures of inflammation (C-reactive protein [CRP], interleukin-6 [IL-6], and tumor necrosis factor alpha [TNFalpha]), and radiographic joint damage (Larsen score; n = 93 patients) was examined in RA patients by multivariable regression analysis first controlling for age, race, and sex, and then for obesity (BMI) and inflammation (TNFalpha, IL-6, and CRP).

RESULTS

Concentrations of all adipocytokines were significantly higher in RA patients than in controls; for visfatin and adiponectin, this association remained significant after adjusting for BMI, inflammation, or both. Visfatin concentrations were associated with higher Larsen scores, and this association remained significant after adjustment for age, race, sex, disease duration, BMI, and inflammation (odds ratio [OR] 2.38 [95% confidence interval (95% CI) 1.32-4.29], P = 0.004). Leptin concentrations showed a positive association with the BMI (rho = 0.58, P < 0.01) and showed a negative association with the Larsen score after adjustment for inflammation (OR 0.32 [95% CI 0.17-0.61], P < 0.001), but not after adjustment for BMI (OR 0.86 [95% CI 0.42-1.73], P = 0.67).

CONCLUSION

Concentrations of adipocytokines are increased in patients with RA and may modulate radiographic joint damage. Visfatin is associated with increased, and leptin with reduced, levels of radiographic joint damage.

Common inflammatory mediators orchestrate pathophysiological processes in rheumatoid arthritis and atherosclerosis

RA is characterized by a systemic inflammatory state, in which immune cells and soluble mediators play a crucial role. These inflammatory processes resemble those in other chronic inflammatory diseases, such as atherosclerosis. The chronic systemic inflammation in RA can be considered as an independent risk factor for the development of atherosclerosis, and represents an important field to investigate the reasons of the increase of acute cardiovascular events in RA. In the present review, we focused on several mediators of autoimmunity, inflammation and endothelial dysfunction, which can be considered the most promising targets to prevent atherogenesis in RA. Among several mediators, the pro-inflammatory cytokine TNF-alpha has been shown as a crucial factor to induce atherosclerosis in RA patients.