Baseline adiponectin and leptin levels in predicting an increased risk of disease activity in rheumatoid arthritis: A meta-analysis and systematic review

Clinical Features and Disease Activity in Psoriatic Arthritis: A Sex-Related Perspective on Leptin and Comorbidity

Background/Objectives: Many studies have addressed the sex differences in patients with psoriatic arthritis, although these are aimed more at describing the phenotype than at investigating the causes underlying these differences. The aims of our study were to assess the presence of clinical features in relation to sex, and to measure the effect on disease activity of different comorbidities in each sex. Methods: This was a cross-sectional study in which the following factors were measured: the clinical features of the disease, disease activity, the physical function and the disease impact. We measured serum leptin levels, to eliminate the effect of obesity on leptin levels, and a leptin/BMI ratio was calculated. The comorbid conditions evaluated included anxiety and depression, and sleep quality. Results: A total of 203 patients participated in this study. The mean age was 54.6 ± 11.3, and 46.8% of the patients were women. Women less frequently presented axial involvement (8% vs. 28%; p < 0.001) and more commonly had enthesitis (2 vs. 0.3; p < 0.001). They also had higher DAPSA (16.4 vs. 13.4; p < 0.001) and PsAID12 scores (4.1 vs. 2.9; p < 0.001), worse HAQ results (0.8 vs. 0.5; p < 0.001), and greater FACIT-F scores (32.7 vs. 38.1; p < 0.001). As for the comorbid conditions, women presented a higher leptin/BMI ratio (0.8 vs. 0.2; p < 0.001), higher levels of HADS-A (6.9 vs. 4.7; p < 0.001) and HADS-D (4.9 vs. 3.4; p < 0.001), and poorer ISI (9.3 vs. 7.0; p < 0.001). By sex, pain affecting women was associated with the leptin/BMI ratio (β: 0.29; p < 0.004; 95%CI: 0.3-1.6) and sleep quality (β: 0.31; p < 0.004; 95%CI: 0.04-0.25; R2: 0.26). The leptin/BMI ratio was not associated with pain in men (p = 0.46). Conclusions: Sex was associated with several clinical manifestations. Leptin/BMI ratio levels were associated with pain in women, but not in men.

Obesity in rheumatological practice

Obesity is a chronic disease that leads to the development of secondary metabolic disturbances and diseases and strongly contributes to increased morbidity and mortality. On the other hand, musculoskeletal disorders are currently the main cause of disability and the second most frequent reason for visits to the doctor. Many studies clearly show that excessive body weight adversely affects the course of almost all musculoskeletal system diseases, from osteoarthritis, through metabolic, systemic connective tissue, to rarely diagnosed diseases. The impact of increased fat mass on the musculoskeletal system is presumably complex in nature and involves the influence of biomechanical, dietary, genetic, inflammatory and metabolic factors. Due to the epidemic nature of obesity and its serious health consequences, this disease requires energetic treatment. It is always based on lifestyle modification enriched, if necessary, by pharmacological and, in justified cases, surgical treatment.

Adipocytokines and Associations With Abnormal Body Composition in Rheumatoid Arthritis

OBJECTIVE

We determined associations between adipokines and abnormal body composition in patients with rheumatoid arthritis (RA).

METHODS

Combining data from three RA cohorts, whole-body dual-energy absorptiometry measures of appendicular lean mass and fat mass indices were converted to age-, sex-, and race- and ethnicity-specific Z scores. Lean mass relative to fat mass was determined based on prior methods. Independent associations between body composition profiles and circulating levels of adiponectin, leptin, and fibroblast growth factor (FGF)-21 were assessed using linear and logistic regression models adjusting for demographic characteristics and study cohort. We also determined the improvement in the area under the curve (AUC) for prediction of low lean mass when adipokines were added to predictive models that included clinical factors such as demographic characteristics, study, and body mass index (BMI).

RESULTS

Among 419 participants, older age was associated with higher levels of all adipokines, whereas higher C-reactive protein level was associated with lower adiponectin levels and higher FGF-21 levels. Greater fat mass was strongly associated with lower adiponectin levels and higher leptin and FGF-21 levels. Higher levels of adiponectin, leptin, and FGF-21 were independently associated with low lean mass. The addition of adiponectin and leptin levels to regression models improved prediction of low lean mass when combined with demographic characteristics, study, and BMI (AUC 0.75 vs. 0.66).

CONCLUSION

Adipokines are associated with both excess adiposity and low lean mass in patients with RA. Improvements in the prediction of body composition abnormalities suggest that laboratory screening could help identify patients with altered body composition who may be at greater risk of adverse outcomes.

Adiponectin and Leptin as Biomarkers of Disease Activity and Metabolic Disorders in Rheumatoid Arthritis Patients

Background

Rheumatoid arthritis (RA) is an autoimmune disease, characterized by inflammation of multiple joints, resulting in irreversible cartilage and bone destruction. Chronic disease activity may be associated with metabolic disorders and premature atherosclerosis. Adipokines are involved not only in metabolism regulation, but also in inflammatory and immune response.

Aim

This study is designed to explore relationships between adipokines (adiponectin, leptin) and metabolic parameters, as well as disease activity, in patients with chronic RA.

Methods

This cross-sectional study enrolled 109 patients with RA. The clinical assessment was performed including tender and swollen joint counts, Disease Activity Score 28 (DAS28), body mass index (BMI). The following laboratory parameters were performed: erythrocyte sedimentation rate, C-reactive protein, glucose, lipid profile, creatinine. Serum levels of adiponectin and leptin were assessed by enzyme-linked immunosorbent assay (ELISA).

Results

The mean adiponectin and leptin serum concentrations remained within normal ranges. Both, adiponectin and leptin levels were not associated with current disease activity markers (clinical and laboratory), and type of treatment. Significant relationships were found between adipokines and metabolic parameters, as well as with coexistent conditions and RA characteristics. Higher leptin levels were noticed in patients with hypertension. In the multiple linear regression analysis, correlations were confirmed. Adiponectin was positively correlated with HDL-C (b = 0.37, p < 0.001), age (b = 0.39, p< 0.001), and negatively with glucose (b = -0.17, p = 0.03). Leptin was positively correlated with BMI (b = 0.58, p < 0.001), and negatively with estimated glomerular filtration rate (eGFR) (b = -0.30, p < 0.001).

Conclusion

The results of this study show the value of adipokines as indicators of metabolic disorders, rather than inflammatory markers in patients with chronic RA, treated with immunosuppressive or biological drugs. High leptin level may indicate poor prognostic factors, kidney and cardiovascular complications. Adiponectin seems to be protective against metabolic disorders in chronic RA.

Adipocytokines and achievement of low disease activity in rheumatoid arthritis

PURPOSE

To determine if adipocytokines are independently associated with the achievement of low disease activity (LDA) over long-term follow-up in a large rheumatoid arthritis (RA) registry.

METHODS

This cohort study evaluated adults with RA from the Veteran's Affairs RA Registry. Adipocytokines (adiponectin, leptin, and fibroblast growth factor [FGF]-21) and inflammatory cytokines were measured as part of a multi-analyte panel on banked serum from enrollment. Covariates were derived from medical record, biorepository, and registry databases. Multivariable Cox proportional hazard models evaluated associations between adipocytokines and rates of 1) DAS28 LDA and remission, 2) individual Boolean remission criteria and 3) initiation of a new bDMARD or tsDMARD.

RESULTS

There were 1,276 participants with a DAS28 >3.2 at enrollment. Of these, 827 achieved LDA and 598 achieved remission over 2,287 and 4,096 person-years, respectively. Patients in the highest quartile of adiponectin had lower rates LDA before and after adjustment [aHR Q4: 0.68 (0.53,0.87) p<0.001]. Those in the highest quartile of leptin and FGF-21 also had lower rates of LDA. Higher quartiles of adipocytokines were also associated with lower rates of achieving a low patient/evaluator global scores and low tender joint counts. Among 1,236 biologic-naïve participants, values above the median for adiponectin [HR: 1.67 (1.23,1.26) p = 0.001] and FGF-21 [HR: 1.27 (1.09,1.47) p = 0.002] were associated with a greater likelihood of initiating a b/tsDMARD.

CONCLUSIONS

Adipocytokines may serve as prognostic biomarkers of a more severe RA disease course. Additional study is needed to determine whether adipocytokines are phenotypic markers or whether they actively promote disease progression.

Elevations in adipocytokines and mortality in rheumatoid arthritis

OBJECTIVES

This study assessed whether circulating levels of adiponectin and leptin are associated with higher mortality in patients with RA.

METHODS

Participants were adults from the Veterans Affairs RA Registry. Adipokines and inflammatory cytokines were measured as part of a multi-analyte panel on banked serum at enrolment. Dates and causes of death were derived from the Corporate Data Warehouse and the National Death Index. Covariates were derived from medical record, biorepository and registry databases. Multivariable Cox proportional hazard models evaluated associations between biomarkers and all-cause and cause-specific mortality.

RESULTS

A total of 2583 participants were included. Higher adiponectin levels were associated with older age, male sex, white race, lower BMI, autoantibody seropositivity, radiographic damage, longer disease duration, prednisone use and osteoporosis. Higher adiponectin concentrations were also associated with higher levels of inflammatory cytokines but not higher disease activity at enrolment. Leptin was primarily associated with greater BMI and comorbidity. The highest quartile of adiponectin (vs lowest quartile) was associated with higher all-cause mortality [hazard ratio (HR): 1.46 (95% CI: 1.11, 1.93), P = 0.009] and higher cardiovascular mortality [HR: 1.85 (95% CI: 1.24, 2.75), P = 0.003], after accounting for covariates. Higher leptin levels were also associated with greater all-cause and cancer mortality.

CONCLUSIONS

Elevations in adipokines are associated with age, BMI, comorbidity and severe disease features in RA and independently predict early death. Associations between adiponectin and inflammatory cytokines support the hypothesis that chronic subclinical inflammation promotes metabolic changes that drive elevations in adipokines and yield adverse health outcomes.

Circulating Mir-140 and leptin improve the accuracy of the differential diagnosis between psoriatic arthritis and rheumatoid arthritis: a case-control study

The differential diagnosis of psoriatic arthritis (PsA) and rheumatoid arthritis (RA) is difficult because of the lack of diagnostic clinical signs and reliable biomarkers. This study investigated microRNAs (miRNA) and adipokines as potential additional markers to discriminate PsA from RA. The expression profile of miRNA (miR-21, miR-140, miR-146a, miR-155, miR-181b, miR-223, miR-let-7e) and inflammatory cytokines (IL-1β, IL-6, IL-17a, IL-23a, TNF-α) from peripheral blood mononuclear cells of PsA and RA patients compared to healthy controls (HC) were evaluated by real-time PCR, and serum adipokines (adiponectin, chemerin, leptin, resistin, visfatin) and cytokines by ELISA assay. Univariable binary logistic regression was used to find the association between PsA and potential predictors. The gene expression of miRNA and cytokines and the serum levels of adipokines were found significantly different in PsA and RA patients compared to HC, as well as in PsA versus RA. MiR-140 gene expression resulted up-regulated in PsA patients and reduced in RA in comparison to HC, and, for the first time, significantly higher in PsA compared with RA. Serum levels of IL-23a and leptin were significantly increased in PsA and RA populations than in HC, as well as in PsA versus RA. Furthermore, circulating TNF-α was up-regulated in PsA and RA in comparison to controls, while resulted higher in RA than in PsA. Univariable binary logistic regression analysis found the above-mentioned markers associated to PsA versus RA. Our results first demonstrated an increased expression of circulating miR-140 and serum leptin in PsA patients compared to RA, which were identified as potential additional biomarkers to discriminate PsA from RA. Since the differential diagnosis of PsA and RA poses challenges in clinical practice, our data may help to enhance the diagnostic performance of PsA in daily practice.

Emerging role of leptin in joint inflammation and destruction

Rheumatoid arthritis (RA) is an autoimmune disease characterized by tumor-like hyperplasia and inflammation of the synovium, which causes synovial cell invasion into the bone and cartilage. In RA pathogenesis, various molecules in effector cells (i.e., immune cells and mesenchymal cells) are dysregulated by genetic and environmental factors. Consistent with the early stages of RA, these pathogenic cells cooperate and activate each other directly by cell-to-cell contact or indirectly via humoral factors. Recently, growing evidence has revealed essential role of adipokines, which are multifunctional signal transduction molecules, in the immune system. In this review, we summarize the current understanding of the cross-talk between leptin, one of the most well-known and best-characterized adipokines, and osteoimmunology. Furthermore, we discuss the contribution of leptin to the pathogenesis of RA and its potential mechanisms.

The association between increased body mass index and response to conventional synthetic DMARD treatment in rheumatoid arthritis: Results from the METEOR database

BACKGROUND

Few data exist on the association between increased BMI and response to conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) in rheumatoid arthritis (RA).We aimed to explore the association between increased (overweight or obese) BMI on csDMARD-prescribing, methotrexate-dose and disease activity over 12-months.

METHODS

Participants in an international RA database were stratified into early (<1year post-diagnosis) and established RA. EULAR response, DAS28 remission and treatments were recorded at baseline, 6-months and 12-months. Increased BMI was explored in early and established RA, as predictors of good EULAR response, DAS28 remission, number of csDMARDs and methotrexate-dose, using logistic and linear regression.

RESULTS

Data from 1313 patients, 44.3% with early RA, were examined. In early RA, increased BMI was not significantly associated with remission. In established RA, obese patients on monotherapy were significantly less likely to achieve good EULAR response or DAS28 remission at 6 months and more likely to be treated with combination csDMARDs, compared with normal BMI. In patients taking methotrexate, overweight and obese patients with early and established RA were exposed to higher methotrexate doses (mono- and combination-therapy), with a mean dose of 20mg/week, compared to 15mg/week in those of normal BMI.

CONCLUSION

We observed, compared to patients with normal BMI, overweight and obese individuals experienced more intensive csDMARD exposures. Similar response rates were observed in early RA but increased BMI was associated with reduced response in established RA. Optimisation of targeted RA treatment remains important, particularly in those with increased BMI where response in established disease may be attenuated.

The pleiotropic roles of leptin in metabolism, immunity, and cancer

The discovery of the archetypal adipocytokine leptin and how it regulates energy homeostasis have represented breakthroughs in our understanding of the endocrine function of the adipose tissue and the biological determinants of human obesity. Investigations on leptin have also been instrumental in identifying physio-pathological connections between metabolic regulation and multiple immunological functions. For example, the description of the promoting activities of leptin on inflammation and cell proliferation have recognized the detrimental effects of leptin in connecting dysmetabolic conditions with cancer and with onset and/or progression of autoimmune disease. Here we review the multiple biological functions and complex framework of operations of leptin, discussing why and how the pleiotropic activities of this adipocytokine still pose major hurdles in the development of effective leptin-based therapeutic opportunities for different clinical conditions.

Adipokines and Chronic Rheumatic Diseases: from Inflammation to Bone Involvement

Besides its well-known role as energy storage tissue, adipose tissue is a biologically active tissue that can also be considered as an endocrine organ, as it is able to secrete adipokines. These bioactive factors, similar in structure to cytokines, are involved in several physiological and pathological conditions, such as glucose homeostasis, angiogenesis, blood pressure regulation, control of food intake, and also inflammation and bone homeostasis via endocrine, paracrine, and autocrine mechanisms. Given their pleiotropic functions, the role of adipokines has been evaluated in chronic rheumatic osteoarticular inflammatory diseases, particularly focusing on their effects on inflammatory and immune response and on bone alterations. Indeed, these diseases are characterized by different bone complications, such as local and systemic bone loss and new bone formation. The aim of this review is to summarize the role of adipokines in rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, osteoarthritis, and osteoporosis, especially considering their role in the pathogenesis of bone complications typical of these conditions.

Association of Leptin Levels and Disease Activity in Patients with Early Rheumatoid Arthritis

OBJECTIVE

Previous studies have reported a link between metabolic parameters and disease activity in rheumatoid arthritis (RA), although the evidence is limited in early RA. We aimed to investigate the relationship between disease activity and adipocytokine levels in subjects with early RA.

METHODS

Forty-seven patients with early RA (symptom duration ≤12 months) were enrolled. Disease activity was determined by DAS28-CRP. Patients were treated with DMARDs according to the EULAR recommendations. Subjects were tested before and five months after treatment.

RESULTS

Early RA patients with high disease activity (DAS28-CRP > 4.9) had greater BMI (31.2 ± 6.8 kg/m² vs. 26.7 ± 4.1 kg/m²; p = 0.006) and higher leptin levels (14.62 ± 15.60 ng/mL vs. 7.82 ± 8.00 ng/mL; p = 0.048). Levels of other adipocytokines were not significantly different. Leptin levels were similar in subjects with mild/moderate disease activity and controls. DAS28-CRP was correlated with leptin (r = 0.303, p = 0.039). Leptin levels decreased significantly after treatment (from 10.86 ± 12.34 ng/mL to 9.22 ± 9.29 ng/mL; p = 0.047) along with insulin levels (from 13.68 ± 21.90 mU/L to 7.09 ± 4.72 mU/L; p = 0.010) and HOMA-IR (from 4.39 ± 9.53 to 1.70 ± 1.38; p = 0.012). HDL cholesterol levels increased (from 41 ± 10 mg/dL48 ± 10 mg/dL; p <0.001).

CONCLUSION

Leptin levels were associated with disease activity in patients with early RA and these levels decreased after treatment with DMARDs. Further research is needed to elicit leptin's role to regulate disease activity in early RA.

The Role of Leptin in the Association between Obesity and Psoriasis

Adipose tissue secretes many adipokines which contribute to various metabolic processes, such as blood pressure, glucose homeostasis, inflammation and angiogenesis. The biology of adipose tissue in an obese individual is abnormally altered in a manner that increases the body’s vulnerability to immune diseases, such as psoriasis. Psoriasis is considered a chronic inflammatory skin disease which is closely associated with being overweight and obese. Additionally, secretion of leptin, a type of adipokine, increases dependently on adipose cell size and adipose accumulation. Likewise, high leptin levels also aggravate obesity via development of leptin resistance, suggesting that leptin and obesity are closely related. Leptin induction in psoriatic patients is mainly driven by the interleukin (IL)-23/helper T (Th) 17 axis pathway. Furthermore, leptin can have an effect on various types of immune cells such as T cells and dendritic cells. Here, we discuss the relationship between obesity and leptin expression as well as the linkage between effect of leptin on immune cells and psoriasis progression.

Cardiovascular Risk in Rheumatoid Arthritis and Mechanistic Links: From Pathophysiology to Treatment

Rheumatoid arthritis (RA) is an autoimmune inflammatory arthritis. Inflammation, however, can spread beyond the joints to involve other organs. During the past few years, it has been well recognized that RA associates with increased risk for cardiovascular (CV) disease (CVD) compared with the general population. This seems to be due not only to the increased occurrence in RA of classical CVD risk factors and comorbidities like smoking, obesity, hypertension, diabetes, metabolic syndrome, and others but also to the inflammatory burden that RA itself carries. This is not unexpected given the strong links between inflammation and atherosclerosis and CVD. It has been shown that inflammatory cytokines which are present in abundance in RA play a significant role in every step of plaque formation and rupture. Most of the therapeutic regimes used in RA treatment seem to offer significant benefits to that end. However, more studies are needed to clarify the effect of these drugs on various parameters, including the lipid profile. Of note, although pharmacological intervention significantly helps reduce the inflammatory burden and therefore the CVD risk, control of the so-called classical risk factors is equally important. Herein, we review the current evidence for the underlying pathogenic mechanisms linking inflammation with CVD in the context of RA and reflect on the possible impact of treatments used in RA.

Adipokines: New Potential Therapeutic Target for Obesity and Metabolic, Rheumatic, and Cardiovascular Diseases

Besides its role as an energy storage organ, adipose tissue can be viewed as a dynamic and complex endocrine organ, which produces and secretes several adipokines, including hormones, cytokines, extracellular matrix (ECM) proteins, and growth and vasoactive factors. A wide body of evidence showed that adipokines play a critical role in various biological and physiological functions, among which feeding modulation, inflammatory and immune function, glucose and lipid metabolism, and blood pressure control. The aim of this review is to summarize the effects of several adipokines, including leptin, diponectin, resistin, chemerin, lipocalin-2 (LCN2), vaspin, omentin, follistatin-like 1 (FSTL1), secreted protein acidic and rich in cysteine (SPARC), secreted frizzled-related protein 5 (SFRP5), C1q/TNF-related proteins (CTRPs), family with sequence similarity to 19 member A5 (FAM19A5), wingless-type inducible signaling pathway protein-1 (WISP1), progranulin (PGRN), nesfatin-1 (nesfatin), visfatin/PBEF/NAMPT, apelin, retinol binding protein 4 (RPB4), and plasminogen activator inhibitor-1 (PAI-1) in the regulation of insulin resistance and vascular function, as well as many aspects of inflammation and immunity and their potential role in managing obesity-associated diseases, including metabolic, osteoarticular, and cardiovascular diseases.

Molecular Mechanisms of Sex-Related Differences in Arthritis and Associated Pain

Clinical conditions leading to chronic pain show important sex-related differences in the prevalence, severity, and degree of functional disability. Decades of epidemiological and clinical studies have demonstrated that women are more sensitive to pain than men. Arthritis, including rheumatoid arthritis (RA) and osteoarthritis (OA), is much more prevalent in females and accounts for the majority of pain arising from musculoskeletal conditions. It is therefore important to understand the mechanisms governing sex-dependent differences in chronic pain, including arthritis pain. However, research into the mechanisms underlying the sex-related differences in arthritis-induced pain is still in its infancy due to the bias in biomedical research performed largely in male subjects and animals. In this review, we discuss current advances in both clinical and preclinical research regarding sex-related differences in the development or severity of arthritis and associated pain. In addition, sex-related differences in biological and molecular mechanisms underlying the pathogenesis of arthritis pain, elucidated based on clinical and preclinical findings, are reviewed.

Atherosclerosis in Rheumatoid Arthritis: Promoters and Opponents

Substantial epidemiological data identified cardiovascular (CV) diseases as a main cause of mortality in patients with rheumatoid arthritis (RA). In light of this, RA patients may benefit from additional CV risk screening and more intensive prevention strategies. Nevertheless, current algorithms for CV risk stratification still remain tailored on general population and are burdened by a significant underestimation of CV risk in RA patients. Acute CV events in patients with RA are largely related to an accelerated atherosclerosis. As pathophysiological features of atherosclerosis overlap those occurring in the inflamed RA synovium, the understanding of those common pathways represents an urgent need and a leading challenge for CV prevention in patients with RA. Genetic background, metabolic status, gut microbiome, and systemic inflammation have been also suggested as additional key pro-atherosclerotic factors. The aim of this narrative review is to update the current knowledge about pathophysiology of atherogenesis in RA patients and potential anti-atherosclerotic effects of disease-modifying anti-rheumatic drugs.

Characterization of the inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction: a hypothesis to explain influence of sex on the evolution and potential treatment of the disease

Accumulating evidence points to the existence of an inflammatory-metabolic phenotype of heart failure with a preserved ejection fraction (HFpEF), which is characterized by biomarkers of inflammation, an expanded epicardial adipose tissue mass, microvascular endothelial dysfunction, normal-to-mildly increased left ventricular volumes and systolic blood pressures, and possibly, altered activity of adipocyte-associated inflammatory mediators. A broad range of adipogenic metabolic and systemic inflammatory disorders - e.g. obesity, diabetes and metabolic syndrome as well as rheumatoid arthritis and psoriasis - can cause this phenotype, independent of the presence of large vessel coronary artery disease. Interestingly, when compared with men, women are both at greater risk of and may suffer greater cardiac consequences from these systemic inflammatory and metabolic disorders. Women show disproportionate increases in left ventricular filling pressures following increases in central blood volume and have greater arterial stiffness than men. Additionally, they are particularly predisposed to epicardial and intramyocardial fat expansion and imbalances in adipocyte-associated proinflammatory mediators. The hormonal interrelationships seen in inflammatory-metabolic phenotype may explain why mineralocorticoid receptor antagonists and neprilysin inhibitors may be more effective in women than in men with HFpEF. Recognition of the inflammatory-metabolic phenotype may improve an understanding of the pathogenesis of HFpEF and enhance the ability to design clinical trials of interventions in this heterogeneous syndrome.

Adipokines and periodontal markers as risk indicators of early rheumatoid arthritis: a cross-sectional study

OBJECTIVE

To establish the association between adipokine levels and markers of periodontal involvement as risk indicators of early stages of RA (eRA) and the interaction between the presence of markers of periodontal disease with adipokine in eRA individuals.

MATERIALS AND METHODS

Fifty-one patients with a diagnosis of eRA and 51 healthy controls matched for age and sex were studied. Clinical joint condition, clinical and serological markers of disease activity, serum adipokine levels (leptin, adiponectin, resistin, adipsin, vaspin, and IL-6), periodontal diagnosis, presence of Porphyromonas gingivalis, and related IgG1 and IgG2 antibodies were evaluated. Comparisons were made between eRA and healthy controls for periodontal indicators and adipokines. A subgroup analysis was realized with a non-conditional logistic regression to establish the association between the levels of leptin in individuals with eRA and controls according to the periodontal condition, presence of P. gingivalis, or high titers of IgG antibodies against P. gingivalis.

RESULTS

The condition of overweight or obesity is associated with the diagnosis of eRA (p = 0.05), and these individuals also have higher levels of leptin (p = 0.001) and vaspin (p = 0.007). Higher frequency of P. gingivalis (p = 0.001) was found in the eRa group. Individuals with eRA with higher IgG2 titers against P. gingivalis had higher levels of leptin (OR: 1.66 (CI 95% 1.01-2.73)); however, individuals with periodontitis or P. gingivalis with eRA were associated with highest levels of leptin (OR: 1.86, CI 95% 1.19-24.3; and OR: 2.04, CI 95% 1.37-3 respectively).

CONCLUSIONS

eRA individuals have high levels of leptin and vaspin. However, the presence of periodontitis and related-periodontal disease markers showed an effect only in leptin levels in eRA individuals.

CLINICAL RELEVANCE

Emphasizing in personalized medicine, monitoring serum leptin levels and periodontitis markers can improve the early diagnosis of RA.

Tocilizumab Increases Body Weight and Serum Adipokine Levels in Patients with Rheumatoid Arthritis Independently of Their Treatment Response: a Retrospective Cohort Study

BACKGROUND

Causes of weight change after tocilizumab treatment are unclear. We aimed to investigate the effects of tocilizumab treatment on body weight and serum adipokine levels in patients with rheumatoid arthritis (RA).

METHODS

In this retrospective cohort study, we evaluated weight changes in patients with RA who received methotrexate (Cohort I) or tocilizumab with methotrexate (Cohorts II and III) for 24 weeks. Adipokine concentrations at baseline and 24 weeks were analyzed in Cohorts I and III. Cohorts I and II received tocilizumab therapy for an additional 48 weeks, during which weight changes were monitored (24-72 weeks).

RESULTS

No significant weight change occurred after 24 weeks of methotrexate treatment (mean difference, -0.2 kg; P = 0.630), but was observed after 24 weeks of tocilizumab treatment (mean difference, +0.9 kg; P = 0.010). Weight changed regardless of the treatment response in both treatment groups. The leptin-adiponectin ratio (P = 0.015) and levels of adiponectin (P < 0.001), leptin (P < 0.001), and resistin (P = 0.003) increased significantly after 24 weeks of tocilizumab, but not methotrexate treatment. After 24, 48 and 72 weeks of tocilizumab treatment in Cohort II, mean (95% confidence interval [CI]) weight changes from baseline were +0.7 (0.0-1.4), +1.2 (0.4-2.0) and +1.1 (0.2-2.0) kg, respectively, and mean (95% CI) percent weight changes from baseline were +1.3% (0.1%-2.6%), +2.2% (0.7%-3.6%), and +2.0% (0.4%-3.7%) at 24, 48, and 72 weeks, respectively.

CONCLUSION

Weight and the leptin-adiponectin ratio increased after tocilizumab treatment. Given that cardiovascular (CV) risk factors may deteriorate in patients with RA who receive tocilizumab, further studies are required to determine the effects of weight gain on CV outcomes in these patients.

Link Between Synovial and Myocardial Inflammation: Conceptual Framework to Explain the Pathogenesis of Heart Failure with Preserved Ejection Fraction in Patients with Systemic Rheumatic Diseases

Patients with a broad range of systemic rheumatic diseases are at increased risk of heart failure (HF), an event that is not related to traditional cardiovascular risk factors or underlying ischaemic heart disease. The magnitude of risk is linked to the severity of arthritic activity, and HF is typically accompanied by a preserved ejection fraction. Subclinical evidence for myocardial fibrosis, microcirculatory dysfunction and elevated cardiac filling pressures is present in a large proportion of patients with rheumatic diseases, particularly those with meaningful systemic inflammation. Drugs that act to attenuate pro-inflammatory pathways (methotrexate and antagonists of tumour necrosis factor and interleukin-1) may ameliorate myocardial inflammation and cardiac structural abnormalities and reduce the risk of HF events.

Characterization, Pathogenesis, and Clinical Implications of Inflammation-Related Atrial Myopathy as an Important Cause of Atrial Fibrillation

Historically, atrial fibrillation has been observed in clinical settings of prolonged hemodynamic stress, eg, hypertension and valvular heart disease. However, recently, the most prominent precedents to atrial fibrillation are metabolic diseases that are associated with adipose tissue inflammation (ie, obesity and diabetes mellitus) and systemic inflammatory disorders (ie, rheumatoid arthritis and psoriasis). These patients typically have little evidence of left ventricular hypertrophy or dilatation; instead, imaging reveals abnormalities of the structure or function of the atria, particularly the left atrium, indicative of an atrial myopathy. The left atrium is enlarged, fibrotic and noncompliant, potentially because the predisposing disorder leads to an expansion of epicardial adipose tissue, which transmits proinflammatory mediators to the underlying left atrium. The development of an atrial myopathy not only leads to atrial fibrillation, but also contributes to pulmonary venous hypertension and systemic thromboembolism. These mechanisms explain why disorders of systemic or adipose tissue inflammation are accompanied an increased risk of atrial fibrillation, abnormalities of left atrium geometry and an enhanced risk of stroke. The risk of stroke exceeds that predicted by conventional cardiovascular risk factors or thromboembolism risk scores used to guide the use of anticoagulation, but it is strongly linked to clinical evidence and biomarkers of systemic inflammation.

Сandidate SNP-markers of rheumatoid arthritis that can significantly alter the affinity of the TATA-binding protein for human gene promoters

Rheumatoid polyarthritis (RA) is an autoimmune disease with autoantibodies, including antibodies to citrullant antigens and proinflammatory cytokines, such as TNF-α and IL-6, which are involved in the induction of chronic synovitis, bone erosion, followed by deformity. Immunopathogenesis is based on the mechanisms of the breakdown of immune tolerance to its own antigens, which is characterized by an increase in the activity of T-effector cells, causing RA symptomatology. At the same time, against the background of such increased activity of effector lymphocytes, a decrease in the activity of a number of regulatory cells, including regulatory T-cells (Treg) and myeloid suppressor cells, is recorded. There is reason to say that it is the change in the activity of suppressor cells that is the leading element in RA pathogenesis. That is why only periods of weakening (remission) of RA are spoken of. According to the more powerful female immune system compared to the male one, the risk of developing RA in women is thrice as high, this risk decreases during breastfeeding and grows during pregnancy as well as after menopause in proportion to the level of sex hormones. It is believed that 50 % of the risk of developing RA depends on the conditions and lifestyle, while the remaining 50 % is dependent on genetic predisposition. That is why, RA fits the main idea of postgenomic predictive-preventive personalized medicine that is to give a chance to those who would like to reduce his/her risk of diseases by bringing his/her conditions and lifestyle in line with the data on his/her genome sequenced. This is very important, since doctors consider RA as one of the most frequent causes of disability. Using the Web service SNP_TATA_Z-tester (http://beehive.bionet.nsc.ru/cgi-bin/mgs/tatascan_fox/start.pl), 227 variants of single nucleotide polymorphism (SNP) of the human gene promoters were studied. As a result, 43 candidate SNP markers for RA that can alter the affinity of the TATA-binding protein (TBP) for the promoters of these genes were predicted.

Association of adiponectin and adiponectin receptor gene polymorphisms with rheumatoid arthritis in a Chinese population

PURPOSE

To explore the association of adiponectin (AD) and adiponectin receptor (ADR) gene single-nucleotide polymorphisms (SNPs) with genetic susceptibility to rheumatoid arthritis (RA) in a Chinese population.

STUDY DESIGN

Five AD SNPs (rs266729, rs2241766, rs1063537, rs2082940 and rs1063539) and two ADR SNPs (rs7539542 and rs12342) were genotyped in a cohort of 617 patients with RA and 639 healthy controls. Seven SNPs were genotyped using TaqMan genotyping assays on the Fluidigm 192.24 system. The concentration of AD in plasma was examined by ELISA.

RESULTS

Patients with RA showed a considerably lower plasma level of AD than healthy controls (p=0.002). No significant differences were observed for the distribution of allele and genotype frequencies of rs266729, rs2241766, rs2082940, rs1063539, rs7539542 and rs12342 SNPs between patients with RA and controls. The genotype effects of recessive and dominant models were also analysed, but no marked evidence for association was found. However, further analysis in female patients with RA showed that the frequency of the AD gene rs1063539 GG genotype was nominally significantly higher in patients who were anti-cyclic citrullinated peptide (anti-CCP) antibody-positive (p=0.040). No significant differences in serum AD level were observed in patients with RA with different genotypes.

CONCLUSIONS

rs266729, rs2241766, rs2082940 and rs1063539 in the AD gene and rs7539542 and rs12342 in the ADR gene are possibly not associated with genetic susceptibility to RA, but the A D gene rs1063539 locus was possibly associated with anti-CCP in RA female patients.

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.

The conundrum of patients with obesity, exercise intolerance, elevated ventricular filling pressures and a measured ejection fraction in the normal range

Patients with obesity, a reduced exercise capacity, increased cardiac filling pressures and a measured left ventricular ejection fraction in the normal range do not have a homogeneous disorder, but instead, exhibit one of three phenotypes. First, many obese people exhibit sodium retention, plasma volume expansion and cardiac enlargement, and some are likely to have heart failure that is related to hypervolaemia, even though cardiac index and circulating levels of natriuretic peptides are not meaningfully increased. Second, in some middle-aged men and women (particularly those with minimal co-morbidities), levels of natriuretic peptides increase markedly and can lower systemic vascular resistance, thus leading to high-output heart failure (HOHF) and glomerular hyperfiltration. Third, older obese people, particularly women with multiple co-morbidities, exhibit the syndrome of heart failure with a preserved ejection fraction (HFpEF). Despite degrees of plasma volume expansion similar to HOHF, these patients exhibit only modestly increased ventricular dimensions and circulating levels of natriuretic peptides (despite a high prevalence of atrial fibrillation), and glomerular function is characteristically impaired. A conceptual framework is proposed to distinguish among the three phenotypes seen in obese patients with exercise intolerance, increased ventricular filling pressures and a measured left ventricular ejection fraction in the normal range, since they may respond differently to therapeutic interventions. Efforts are needed to enhance the recognition of heart failure in obese people and to ensure that clinical trials that are designed to study patients with HFpEF actually enrol those who have the disease.

Serum adiponectin as a predictor of laboratory response to anti-TNF-α therapy in rheumatoid arthritis

Introduction

While adiponectin is typically viewed as an anti-inflammatory mediator, such an activity of adiponectin in rheumatoid arthritis (RA) is not so obvious. In the present study we examined whether serum levels of adiponectin reflect the clinical phenotype of RA patients and/or correlate with severity of the disease and the response to anti-TNF-α therapy.

Material and methods

Twenty-one female RA patients qualified to receive anti-TNF-α treatment were prospectively assessed before and after 12 weeks of therapy. Patients underwent full clinical and biochemical assessment. Disease activity was assessed by the Modified Disease Activity Scores (DAS28). Serum concentrations of adiponectin were measured with an immunoassay. The individuals were divided into two subgroups according to whether their baseline serum adiponectin was below or above the median value. The subgroups did not differ in basic demographic, anthropometric, and clinical parameters.

Results

Anti-TNF-α treatment resulted in a significant clinical (DAS28) improvement in patients from both subgroups, but no significant differences between basal and post-treatment serum adiponectin concentrations were observed. However, patients with higher baseline adiponectin experienced a significant and more pronounced improvement in laboratory parameters of inflammation (ESR, CRP, neutrophil count, neutrophil-to-lymphocyte ratio).

Conclusions

It is possible that adiponectin exerts systemic anti-inflammatory effects independently of the local activity of RA.

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.

Serum levels of leptin and adiponectin are not associated with disease activity or treatment response in multiple sclerosis

Adipokines secreted by fatty tissue have inflammatory properties and are suggested biomarkers of MS disease activity. To assess this, 88 MS patients were followed with nine repeated measurements of leptin and adiponectin and 12 magnetic resonance imaging (MRI) scans for two years; six months without any immunomodulatory treatment followed by 18 months during interferon-beta (IFNB) treatment. Serum levels of leptin dropped and adiponectin increased upon initiation of IFNB-therapy, but were not associated with clinical or MRI disease activity or with treatment response. Our findings indicate that leptin and adiponectin are not useful as biomarkers of MS disease activity.

Leptin as an obesity marker in rheumatoid arthritis

The determination of excess of body fat mass provides a more suitable determinant of obesity in rheumatoid arthritis patients; however, body mass index (BMI) may not be accurate for the quantification of adiposity. To identify a marker of excess adiposity in women with rheumatoid arthritis (RA) using different methods for fat mass evaluation. A cross-sectional study was conducted in adult female patients with RA. Disease activity was assessed by DAS28-ESR, and obesity was determined by waist circumference (WC), BMI and dual-energy X-ray absorptiometry (DXA). The Human Bone Metabolism kit (Merck Millipore, Darmstadt, Alemanha) was used to determine the plasma levels of leptin, TNF-α, IL-6, and IL-1β by quantification of serum proteins by technical microspheres (LUMINEX, TX, USA). Adiponectin was measured by enzyme-linked immunosorbent assay sandwich kit (R&D Systems, Minneapolis, MN, USA). Eighty-nine female patients, median age of 55.4 (± 11.6) years, and median disease duration of 16.4 (± 14.9) years were included. The frequency of obesity was 33.7% according to BMI, 89.9% with WC, and 56.1% with DXA. The median serum leptin concentration was the only marker that correlated with body fat percentage according to the three methods. This correlation was positive and not influenced by DAS28, C-reactive protein, erythrocyte sedimentation rate, or inflammatory cytokines levels (IL-6, TNF-α, IL-1β). Analysis of ROC curves determined the cut-off point of 10.3 ng/mL of leptin as an obesity marker, with a sensitivity of 96.43% and a specificity of 23.81%. Serum leptin correlates positively with fat mass and is potentially useful in excess fat mass determination in clinical practice.

Obesity, Fat Mass and Immune System: Role for Leptin

Obesity is an epidemic disease characterized by chronic low-grade inflammation associated with a dysfunctional fat mass. Adipose tissue is now considered an extremely active endocrine organ that secretes cytokine-like hormones, called adipokines, either pro- or anti-inflammatory factors bridging metabolism to the immune system. Leptin is historically one of most relevant adipokines, with important physiological roles in the central control of energy metabolism and in the regulation of metabolism-immune system interplay, being a cornerstone of the emerging field of immunometabolism. Indeed, leptin receptor is expressed throughout the immune system and leptin has been shown to regulate both innate and adaptive immune responses. This review discusses the latest data regarding the role of leptin as a mediator of immune system and metabolism, with particular emphasis on its effects on obesity-associated metabolic disorders and autoimmune and/or inflammatory rheumatic diseases.

Autoimmunity in 2016

The number of peer-reviewed articles published during the 2016 solar year and retrieved using the "autoimmunity" key word remained stable while gaining a minimal edge among the immunology articles. Nonetheless, the quality of the publications has been rising significantly and, importantly, acquisitions have become available through scientific journals dedicated to immunology or autoimmunity. Major discoveries have been made in the fields of systemic lupus erythematosus, rheumatoid arthritis, autoimmunity of the central nervous system, vasculitis, and seronegative spondyloarthrithritides. Selected examples include the role of IL17-related genes and long noncoding RNAs in systemic lupus erythematosus or the effects of anti-pentraxin 3 (PTX3) in the treatment of this paradigmatic autoimmune condition. In the case of rheumatoid arthritis, there have been reports of the role of induced regulatory T cells (iTregs) or fibrocytes and T cell interactions with exciting implications. The large number of studies dealing with neuroimmunology pointed to Th17 cells, CD56(bright) NK cells, and low-level TLR2 ligands as involved in multiple sclerosis, along with a high salt intake or the micriobiome-derived Lipid 654. Lastly, we focused on the rare vasculitides to which numerous studies were devoted and suggested that unsuspected cell populations, including monocytes, mucosal-associated invariant T cells, and innate lymphoid cells, may be crucial to ANCA-associated manifestations. This brief and arbitrary discussion of the findings published in 2016 is representative of a promising background for developments that will enormously impact the work of laboratory scientists and physicians at an exponential rate.

Leptin in autoimmune mechanisms of systemic rheumatic diseases

In the last two decades, white adipose tissue (WAT) has been recognized as a key actor of many physiological and pathological conditions. WAT is able to produce mediators, named "adipokines", which may affect systemic homeostasis. In particular, leptin is not only involved in appetite and energy metabolism, but also in immune system. Increasing evidence established that leptin can regulate both innate and adaptive immunity mainly with pro-inflammatory effects but also, to a lesser extent, with anti-inflammatory features. In autoimmune diseases, a failure or breakdown of the mechanisms of self-tolerance is observed. Leptin, which plays an important role in the control of immune balance, has been involved in autoimmunity generation and maintenance. In this review, it has been provided an up-to-date report about the role of leptin in systemic autoimmune diseases, with particular reference to connective tissue diseases, inflammatory arthritis, and vasculitis.

Leptin Upregulates Peripheral CD4+CXCR5+ICOS+ T Cells via Increased IL-6 in Rheumatoid Arthritis Patients

CD4⁺CXCR5⁺ICOS⁺ T cells, known as Tfh (T Follicular helper) cells, are required for antibody production. Abnormal production and differentiation of Tfh cells are involved in many autoimmune diseases, including rheumatoid arthritis (RA). Leptin has the property of modulating immune system. Here, we explored the effect of leptin on CD4⁺CXCR5⁺ICOS⁺ T cells production in RA patients. Serum leptin levels were measured by enzyme-linked immunosorbent assay (ELISA). Peripheral blood mononuclear cells (PBMC) stimulated with CD3/CD28 were cultured in the presence and absence of leptin and with or without anti-IL-6 receptor (anti-IL-6R), anti-IL-21R, and anti-IL-12R antibody respectively. IL-6, IL-21, and IL-12 levels were determined by ELISA. Bcl-6 was detected by reverse transcription-polymerase chain reaction. STAT1, pSTAT1, STAT3, and pSTAT3 were examined by western blot. We found that leptin levels were higher in RA patients than healthy controls. Leptin-stimulated RA PBMC upregulated CD4⁺CXCR5⁺ICOS⁺ T cells, along with increased IL-6, IL-21, and IL-12.CD4⁺CXCR5⁺ICOS⁺ T cells, Bcl-6 mRNA expression, pSTAT1, and pSTAT3 obviously declined when anti-IL-6R antibody was added into leptin-treated RA PBMC, which suggested that leptin upregulated RA CD4⁺CXCR5⁺ICOS⁺ T cells via increased IL-6 by activation of STAT1 and STAT3. We presented an innovative mechanism on how leptin participated in RA pathogenesis.

Relationship between leptin concentrations and disease activity in patients with rheumatoid arthritis

BACKGROUND AND OBJECTIVE

Multiple studies have found a direct relationship between leptin concentrations and disease activity in rheumatoid arthritis.

PATIENTS AND METHODS

We studied 77 patients with the diagnosis of rheumatoid arthritis; the leptin determination was through an enzyme immunoassay. Disease activity was assessed by the DAS-28 CRP. A multivariate logistic regression model was used to determine the association between significant variables and leptin concentrations.

RESULTS

40.3% of the patients were in remission, 41.6% were mildly active, 11.7% were moderately active and 6.5% were severely active. The results show an independent association between higher concentrations of leptin and disease activity (OR 1.7; 95% CI 1.4-3.2; p .03), the number of swollen joints (OR 4.6; 95% CI 1.7-8.3; p .000), the number of painful joints (OR 3.4; 95% CI 1.6-4.6; p .000), and the presence of metabolic syndrome (OR 1.3; 95% IC 1.2-1,9; p .045).

CONCLUSION

The data suggest that serum leptin is elevated in patients with active RA.

Association between leptin and IL-6 concentrations with cardiovascular risk in patients with rheumatoid arthritis

Pro-inflammatory cytokines such as leptin and IL-6 play an important role in the development of cardiovascular risk. Determine the relationship between leptin and IL-6 concentrations with cardiovascular risk in patients with rheumatoid arthritis. We determined IL-6 and leptin levels in 77 patients with the diagnosis of rheumatoid arthritis. The cardiovascular risk was calculated using the modified Framingham scale. Statistical analysis was performed using SPSS 22 considering a significant p < 0.05. Serum leptin concentrations and cardiovascular risk (CVR) factors were compared and found that there was a significant difference between higher leptin values and disease activity (p 0.047), obesity (p 0.038), positive rheumatoid factor (p 0.009), tobacco (p 0.009), and metabolic syndrome (p 0.001). Likewise, a significant relationship was found between lower leptin concentrations and hydroxychloroquine consumption (p = 0.023). We found significant difference between IL-6 concentrations and disease activity (p 0.028), hypertriglyceridemia (p 0.023), LDL-C (p 0.029), and smoking (0.005). Similarly, an association between hydroxychloroquine consumption and low concentrations of IL-6 was found (p 0.005). Framingham CVR was calculated and the result obtained was multiplied by 1.5. The 35.2% of the population studied had a low Framingham CVR, 38.9% moderate, and 25.9% presented a high risk. We compared the level of CVR and serum leptin and IL-6 concentrations, finding that the highest CVR was the leptin and IL-6 values. There is a positive association between CVR and serum leptin concentrations. It is also significantly associated with traditional and non-traditional risk factors.

Adiposity Measures and Plasma Adipokines in Females with Rheumatoid and Osteoarthritis

The objective of this study was to examine the relationship between adipokines and adiposity in individuals with rheumatoid and osteoarthritis in the Atlantic PATH cohort. Using a nested case-control analysis, participants in the Atlantic PATH cohort with rheumatoid or osteoarthritis were matched for measures of adiposity with participants without a history of arthritis. Both measured and self-reported data were used to examine disease status, adiposity, and lifestyle factors. Immunoassays were used to measure plasma markers. BMI was positively correlated with percentage body fat, fat mass index (FMI), and a change in BMI from 18 years of age in all 3 groups. There were no statistical differences between levels of plasma adipokines; adiponectin levels were 6.6, 7.9, and 8.2 μg/ml, leptin levels were 10.3, 13.7, and 11.5 ng/ml, and resistin levels were 10.0, 12.1, and 10.8 ng/ml in participants without arthritis, with rheumatoid arthritis, and with osteoarthritis, respectively. Those with higher levels of adiponectin were more likely to have osteoarthritis (but not rheumatoid arthritis). No association was found between arthritis types and leptin or resistin. This study demonstrates differences in measures of adiposity and adipokines in specific types of arthritis and highlights the need for more research targeting specific adipokines during arthritic disease progression.