Prevalence of Undiagnosed Diabetes in Rheumatoid Arthritis: an OGTT Study

Inflammatory markers in rheumatic diseases

Immune-mediated rheumatic diseases (IMRDs) are a broad group of pathological conditions based on impaired immunological tolerance to one’s own tissues leading to inflammation and irreversible organ damage. Laboratory diagnosis of IMRDs includes a wide range of biomarkers (autoantibodies, acute phase proteins, cytokines, markers of endothelial damage, components of the complement system, immunoglobulins, cryoglobulins, lymphocyte subpopulations, indicators of bone metabolism, apoptosis markers, genetic markers, etc). One of the leading aspects of laboratory diagnosis of IMRDs is the study of the level of inflammation markers in the blood (erythrocyte sedimentation rate, C-reactive protein (CRP), serum amyloid protein (CAA), ferritin, procalcitonin, apolipoprotein AI, calprotectin, etc). The analysis of inflammation markers makes it possible to assess the disease activity, the nature of the progression and the prognosis of the outcomes of a chronic inflammatory process, as well as the effectiveness of the therapy. The review presents the latest data on the role of the most frequently studied inflammatory markers such as CRP, CAA and ferritin.

Magnitude of impaired fasting glucose and undiagnosed diabetic mellitus and associated risk factors among adults living in Woreta town, northwest Ethiopia: a community-based cross-sectional study, 2021

BACKGROUND

Impaired fasting glucose (IFG) is an early warning system that provides prior information to prevent the future development of DM and diabetes-related problems, but early detection of DM is not practically applicable in Ethiopia. This study was aimed to assess the magnitude of impaired fasting glucose and undiagnosed diabetes mellitus (DM) and associated factors.

METHODS

A community-based, cross-sectional study was conducted from May to June 30, 2021. A structured interviewer-administered questionnaire was used to collect data. Anthropometric measurements were also recorded. A fasting blood sugar (FBS) test was assessed by samples taken early in the morning. Epi-Info 7.2.5.0 was used to enter data, which was then exported to SPSS 25 for analysis. To identify factors associated with IFG, logistics regression was used. The level of statistical significance was declared at p 0.05.

RESULT

Three hundred and twenty-four (324) participants with a mean age of 43.76 ± 17.29 years were enrolled. The overall magnitude of impaired fasting glucose (IFG) and undiagnosed diabetes mellitus (DM) were 43.2% and 10.0%, respectively. Waist circumference (AOR: 1.72, 95% CI 1.23-3.14), hypertension (AOR: 3.48, 95% CI 1.35-8.89), family history of Diabetic mellitus (AOR: 2.34, 95% CI 1.37-5.79) and hypertriglyceridemia (AOR: 2.35, 95% CI 1.41-5.43) were found to be independently associated with impaired fasting glucose.

CONCLUSION

Individuals who are overweight, hypertriglyceridemia, and are hypertensive should have regular checkups and community-based screening.

High prevalence of undiagnosed impaired glucose tolerance in patients with rheumatoid arthritis

Objectives

Although the risk of diabetes mellitus has been recognised in rheumatoid arthritis, undiagnosed dysglycaemia remained under-reported. The study aimed to determine the prevalence and associated factors of dysglycaemia among patients with rheumatoid arthritis, utilising the oral glucose tolerance test.

Methods

This cross-sectional study involved patients with rheumatoid arthritis, aged ⩾30 years. Following an oral glucose tolerance test, they were divided into two: dysglycaemia and normoglycaemia. Demographic and laboratory parameters were compared using logistic regression analyses.

Results

There were 35.5% (55/155) patients with dysglycaemia (including 25.8% impaired glucose tolerance, 7.1% diabetes mellitus and 1.9% with both impaired fasting glucose and impaired glucose tolerance). Patients with dysglycaemia were heavier (65.5 ± 12.3 versus 60.7 ± 10.6 kg, p = 0.01), had wider waist (89.0 ± 12.5 versus 83.1 ± 9.6 cm, p < 0.01), lower high-density lipoprotein cholesterol (1.4 ± 0.3 versus 1.5 ± 0.4 mmol/L, p = 0.02), higher triglyceride (1.3 (0.9-1.8) versus 0.9 (0.8-1.2) mmol/L, p < 0.01) and intercellular adhesion molecule-1 (361.79 (290.38-481.84) versus 315.92 (251.45-407.93) ng/mL, p = 0.01). History of smoking (odds ratio: 5.70, confidence interval: 1.27-25.7), elevated triglyceride (odds ratio: 2.87, confidence interval: 1.33-6.22) and intercellular adhesion molecule-1 (odds ratio: 1.003, confidence interval: 1.001-1.006) were significantly associated with dysglycaemia.

Conclusions

Prevalence of undiagnosed dysglycaemia, particularly impaired glucose tolerance, was high in these patients with rheumatoid arthritis, using a 75-g oral glucose tolerance test, which was not associated with disease activity or corticosteroid use. Those with high triglyceride, history of smoking and elevated intercellular adhesion molecule-1 were the two significant predictors for dysglycaemia in our patients with rheumatoid arthritis. Oral glucose tolerance test could be an important laboratory investigation for dysglycaemia in these high-risk patients.

Prevalence of undiagnosed diabetes and the relative importance of its risk factors among adults in Bangladesh: Findings from a nationwide survey

AIM

To estimate the prevalence of undiagnosed diabetes, and to identify the relative importance of risk factors for undiagnosed diabetes among Bangladeshi adults.

METHOD

Data from 11, 421 Bangladeshi adults aged 18 years and older available from the most recent nationally representative Bangladesh Demographic and Health Survey 2017-18 were used. Anthropometric measurements and fasting blood glucose samples were taken as part of the survey. Prevalence estimates of undiagnosed diabetes was age-standardised with direct standarisation, and risk factors were identified using multilevel mix-effects Poisson regression models with robust variance.

RESULTS

The overall age-standardised prevalence of undiagnosed diabetes was 6.0% (95 %CI, 5.5-6.4%) (men: 6.1%, women: 5.9%). Risk factors associated with undiagnosed diabetes were older age, elevated body mass index (BMI), highest wealth quintile, hypertension, and being male. The top two modifiable risk factors contributing over 50% to undiagnosed diabetes were BMI and wealth quintiles.

CONCLUSION

Undiagnosed diabetes affects a substantial proportion of Bangladeshi adults. Since elevated BMI and the highest wealth quintile are strong risk factors, these offer an opportunity for early detection and screening to reduce undiagnosed diabetes in Bangladesh. In addition, wide-reaching awareness campaigns among the general public, clinicians, and policymakers are needed.

Prevalence of Impaired Fasting Glucose and Type 2 Diabetes in Kazakhstan: Findings From Large Study

Type 2 diabetes mellitus (T2DM) is a serious public health problem. A large proportion of patients with T2DM are unaware of their condition. People with undiagnosed T2DM are at a greater risk of developing complications, whereas prediabetes has an elevated risk of becoming T2DM. The aim of this study is to estimate the prevalence of impaired fasting glucose (IFG), undiagnosed and prior-diagnosed T2DM in Kazakhstan. A cross-sectional study was conducted in four geographically remote regions using the WHO STEP survey instrument. The status of T2DM of 4,753 participants was determined using the WHO diagnostic criteria based on fasting plasma glucose (FPG) level. As a result, the survey-weighted prevalence of IFG was 1.9% (95% CI 1.1%; 3.5%) and of T2DM was 8.0% (95% CI 3.8; 15.9). A total of 54% of T2DM have been newly diagnosed with T2DM. Being 55–64 years old (OR = 2.71, 95% CI 1.12; 6.60) and having lowered HDL-C level (OR = 3.72, 95% CI 1.68; 8.23) were found to be independent predictors for IFG. Being older than 45 years, a female (OR = 0.57, 95% CI 0.39; 0.83), having high waist circumference, was associated with newly diagnosed T2DM. Whereas, the age older than 45 years, high waist circumference, and family history of diabetes (OR = 2.42, 95% CI 1.64; 3.54) were associated with preexisting T2DM. This study shows a high prevalence of IFG and a high proportion of newly diagnosed T2DM in Kazakhstan. A series of risk factors identified in the study may be used to strengthen appropriate identification of IFG or undiagnosed patients in healthcare settings to deliver either preventive or therapeutic interventions aimed to reduce the incidence of T2DM or the delay of their complications. Further longitudinal studies are needed to confirm these associations in our population.

Metabolic Enzyme Triosephosphate Isomerase 1 and Nicotinamide Phosphoribosyltransferase, Two Independent Inflammatory Indicators in Rheumatoid Arthritis: Evidences From Collagen-Induced Arthritis and Clinical Samples

Metabolic intervention is a novel anti-rheumatic approach. The glycolytic regulator NAMPT has been identified as a therapeutic target of rheumatoid arthritis (RA), while other metabolic regulators coordinating NAMPT to perpetuate inflammation are yet to be investigated. We continuously monitored and validated expression changes of Nampt and inflammatory indicators in peripheral while blood cells from rats with collagen-induced arthritis (CIA). Gene transcriptional profiles of Nampt+ and Nampt++ samples from identical CIA rats were compared by RNA-sequencing. Observed gene expression changes were validated in another batch of CIA rats, and typical metabolic regulators with persistent changes during inflammatory courses were further investigated in human subjects. According to expression differences of identified genes, RA patients were assigned into different subsets. Clinical manifestation and cytokine profiles among them were compared afterwards. Nampt overexpression typically occurred in CIA rats during early stages, when iNos and Il-1β started to be up-regulated. Among differentially expressed genes between Nampt+ and Nampt++ CIA rat samples, changes of Tpi1, the only glycolytic enzyme identified were sustained in the aftermath of acute inflammation. Similar to NAMPT, TPI1 expression in RA patients was higher than general population, which was synchronized with increase in RFn as well as inflammatory monocytes-related cytokines like Eotaxin. Meanwhile, RANTES levels were relatively low when NAMPT and TPI1 were overexpressed. Reciprocal interactions between TPI1 and HIF-1α were observed. HIF-1α promoted TPI1 expression, while TPI1 co-localized with HIF-1α in nucleus of inflammatory monocytes. In short, although NAMPT and TPI1 dominate different stages of CIA, they similarly provoke monocyte-mediated inflammation.

Poor glycemic control enhances the disease activity in the RA patients with undiagnosed diabetes—a cross-sectional clinical study

Background

Rheumatoid arthritis (RA), an autoimmune disorder, characterized by systemic inflammation and swollen joints, establishes itself as a critical threat. A pro-inflammatory cytokine TNF-α is a well-known driver of RA pathogenesis and at the same time predisposes to insulin resistance through signal impediment which ultimately paves the way for type 2 diabetes (T2DM). However, in patients with RA, T2DM remains significantly undiagnosed or undertreated, apparently which increases the risk of developing cardio-metabolic comorbidities. This study aimed to evaluate the glycemic status among RA patients and its association with disease activity.

Result

One hundred fifty inpatients RA cases according to ACR/EULAR standards were included in the cross-sectional study who have an average age of 45.4±12.15 years and a median and interquartile period of RA of 2.25 years and 0.48–6 years, respectively. We discovered that 36% of people had T2DM, 26% were prediabetic, and 38% were non-diabetic. Age was shown to be significantly correlated with DM frequency in RA patients (p=0.007). There were 28 patients with elevated disease activity (19%) and 60 patients with low disease activity (40%) in this study. No substantial associations were found in the presence of DM with gender, anti-CCP, RF, disease duration, or DAS28.

Conclusion

RA patients are more likely to experience diabetes, and resultantly a high index of notion must be kept. Clinician should be aware about the affliction of undiagnosed diabetes and prediabetes in RA patients. Furthermore, keeping an eye on glycemic control in RA patients could prevent metabolic and cardiovascular comorbidities in those susceptible patients.

Diabetes mellitus and cardiovascular risk management in patients with rheumatoid arthritis: an international audit

Aim

The objective was to examine the prevalence of atherosclerotic cardiovascular disease (ASCVD) and its risk factors among patients with RA with diabetes mellitus (RA-DM) and patients with RA without diabetes mellitus (RAwoDM), and to evaluate lipid and blood pressure (BP) goal attainment in RA-DM and RAwoDM in primary and secondary prevention.

Methods

The cohort was derived from the Survey of Cardiovascular Disease Risk Factors in Patients with Rheumatoid Arthritis from 53 centres/19 countries/3 continents during 2014–2019. We evaluated the prevalence of cardiovascular disease (CVD) among RA-DM and RAwoDM. The study population was divided into those with and without ASCVD, and within these groups we compared risk factors and CVD preventive treatment between RA-DM and RAwoDM.

Results

The study population comprised of 10 543 patients with RA, of whom 1381 (13%) had DM. ASCVD was present in 26.7% in RA-DM compared with 11.6% RAwoDM (p<0.001). The proportion of patients with a diagnosis of hypertension, hyperlipidaemia and use of lipid-lowering or antihypertensive agents was higher among RA-DM than RAwoDM (p<0.001 for all). The majority of patients with ASCVD did not reach the lipid goal of low-density lipoprotein cholesterol <1.8 mmol/L. The lipid goal attainment was statistically and clinically significantly higher in RA-DM compared with RAwoDM both for patients with and without ASCVD. The systolic BP target of <140 mm Hg was reached by the majority of patients, and there were no statistically nor clinically significant differences in attainment of BP targets between RA-DM and RAwoDM.

Conclusion

CVD preventive medication use and prevalence of ASCVD were higher in RA-DM than in RAwoDM, and lipid goals were also more frequently obtained in RA-DM. Lessons may be learnt from CVD prevention programmes in DM to clinically benefit patients with RA.

High prevalence of steroid-induced glucose intolerance with normal fasting glycaemia during low-dose glucocorticoid therapy: an oral glucose tolerance test screening study

OBJECTIVES

To evaluate the prevalence and risk factors of new-onset glucose metabolism impairment using an oral glucose tolerance test (OGTT) in patients with normal fasting glycaemia on long-term glucocorticoid (GC) treatment.

METHODS

An OGTT was performed in 150 patients without a previous history of pre-diabetes or diabetes who were diagnosed with inflammatory rheumatic diseases and treated with GCs >3 months. All participants underwent clinical and biochemical evaluation for risk factors of diabetes: age, sex, current and cumulative dose of steroids, treatment duration, waist circumference, BMI, Homeostatic Model Assessment for Insulin Resistance, fasting insulin concentration, family history of diabetes, CRP, 28-joint DAS with CRP, type of connective tissue disease and trunk fat percentage measured by DXA. Logistic regression analysis was conducted to evaluate the association between the presence of impaired glucose tolerance (IGT) in the OGTT and analysed risk factors.

RESULTS

A total of 102 patients (68%) had fully normal glucose tolerance. Diabetes, isolated impaired fasting glucose, isolated IGT and combined impaired fasting glucose + IGT was diagnosed in 3.3, 4.67, 19.33 and 4.67% of patients, respectively; 20% of participants had IGT or diabetes despite normal fasting glucose concentration. The median cumulative dose and current dose (5 mg) of GCs and treatment duration were similar compared with the normal glucose tolerance group. In a multivariate logistic regression model, only older age (particularly ≥50 years of age) and trunk fat percentage remained significant factors predicting IGT or diabetes in the OGTT.

CONCLUSION

New-onset GC-induced glucose intolerance, even in patients on long-term low-dose treatment, is prevalent despite normal fasting glucose concentration and patients should be screened with an OGTT despite the absence of classic risk factors of diabetes.

Autoimmune polyglandular syndrome type 3 variant in rheumatoid arthritis

INTRODUCTION

Although type 1 diabetes mellitus is largely associated with autoimmune thyroid disease and this entity has been recently referred to as autoimmune polyglandular syndrome type 3 variant, the autoimmune polyglandular syndrome type 3 variant in patients with rheumatoid arthritis has not been reported so far. We herein describe the first case of rheumatoid arthritis that was associated with autoimmune polyglandular syndrome type 3 variant.

CASE REPORT

A 77-year-old woman with a 15-year history of rheumatoid arthritis (RA) and a 10-year history of type 2 diabetes mellitus (T2D) presented with polyarthralgia and hyperglycaemia. Methotrexate 16 mg/week had been started from the onset and was continued, and adalimumab 40 mg/day was started for RA. Insulin treatment was also started for the diabetes. Laboratory examinations revealed high levels of C-reactive protein (CRP), rheumatoid factor, anti-cyclic citrullinated peptide antibody, and matrix metalloprotease 3. She was admitted multiple times as the symptoms recurred after treatment. Subsequently, based on the clinical course and investigations, she was diagnosed with type 1 diabetes mellitus and Graves' disease occurring during the course of RA and T2D. Her clinical course improved after reinforcement of insulin therapy and the addition of thiamazole therapy.

CONCLUSION

In patients with rheumatoid arthritis, the autoimmune polyglandular syndrome type 3 variant should be considered as the cause of the deterioration.

C-reactive protein and implications in rheumatoid arthritis and associated comorbidities

C-reactive protein (CRP) is routinely assessed as a marker of systemic inflammation in rheumatoid arthritis (RA). However, it is also an immune regulator that plays an important role in inflammatory pathways associated with RA and promotes atherogenic effects. Comorbidities linked to systemic inflammation are common in RA, and CRP has been associated with the risk for cardiovascular disease, diabetes, metabolic syndrome, pulmonary diseases, and depression. The relationship between systemic inflammation, CRP, and comorbidities in RA is complex, and it is challenging to determine how changing CRP levels may affect the risk or progression of these comorbidities. We review the biological role of CRP in RA and its implications for disease activity and treatment response. We also discuss the impact of treatment on CRP levels and whether reducing systemic inflammation and inhibiting CRP-mediated inflammatory pathways may have an impact on conditions commonly comorbid with RA.

Effect of methotrexate use on the development of type 2 diabetes in rheumatoid arthritis patients: A systematic review and meta-analysis

BACKGROUND

The high risk of cardiovascular disease is well recognized in rheumatoid arthritis. Type 2 diabetes also attributes to this increase in risk. Rheumatoid arthritis is a chronic inflammatory condition, which aggravates insulin resistance, placing the patients at a higher risk of type 2 diabetes and subsequent cardiovascular outcomes. Methotrexate treatment, as a gold standard anti-inflammatory drug in the treatment of rheumatoid arthritis has shown beneficial effects on cardiovascular health. However, its impact on type 2 diabetes is still unknown.

OBJECTIVE

To assess the strength of the association between exposure to methotrexate and the rate of development of type 2 diabetes in rheumatoid arthritis patients.

METHODS

All rheumatoid arthritis studies reporting the use of methotrexate as an exposure and type 2 diabetes as an outcome were searched until March 2020 using MEDLINE, Cochrane and Scopus databases. Studies were included if the diagnosis of rheumatoid arthritis was made according to current guidelines or by a rheumatologist, and if there was information about methotrexate exposure and the type 2 diabetes outcome. The author and an independent assessor evaluated the articles for eligibility. Meta-analyses combined relative risk estimates from each study where raw counts were available.

RESULTS

Sixteen studies reporting sufficient data for inclusion in the meta-analyses were identified. Methotrexate showed a promising effect on the risk of type 2 diabetes as this risk decreased in rheumatoid arthritis patients using methotrexate (Relative risk 0.48, 95% CI 0.16, 1.43).

CONCLUSION

Rheumatoid arthritis patients on methotrexate treatment had a lower risk of developing type 2 diabetes compared to rheumatoid arthritis patients not exposed to methotrexate. This finding highlights the need for future, randomized control trials to confirm the beneficial effect of methotrexate on type 2 diabetes in the rheumatoid arthritis population.

A drug-drug interaction study to evaluate the impact of peficitinib on OCT1- and MATE1-mediated transport of metformin in healthy volunteers

Purpose

Peficitinib is an oral pan-Janus kinase inhibitor for the treatment of rheumatoid arthritis. Co-administration of peficitinib with metformin, a type 2 diabetes therapy, can occur in clinical practice. Hepatic and renal uptake of metformin is mediated by organic cation transporter 1 (OCT1) and OCT2, respectively, and its renal excretion by multidrug and toxin extrusion 1 (MATE1) and MATE2-K. This study investigated the effect of peficitinib on metformin pharmacokinetics in vitro and in healthy volunteers.

Methods

Inhibitory effects of peficitinib and its metabolite H2 on metformin uptake into human OCT1/2- and MATE1/2-K-expressing cells were assessed in vitro. In an open-label, drug–drug interaction study, 24 healthy volunteers received a single dose of metformin 750 mg on Days 1 and 10, and a single dose of peficitinib 150 mg on Days 3 and 5–11. Blood and urine samples were collected pre-dose on Days 1 and 10, and at intervals ≤ 48 h post-dose. Metformin concentration was determined by liquid chromatography–tandem mass spectrometry and its pharmacokinetic parameters calculated.

Results

Peficitinib, but not H2, inhibited metformin uptake into OCT1- and MATE1/2-K-expressing cells. Repeated-dose administration of peficitinib reduced metformin area under the concentration–time curve from 0 h extrapolated to infinity (AUC_inf) by 17.4%, maximum plasma concentration (C_max) by 17.0%, and renal clearance (CL_R) by 12.9%. Co-administration of peficitinib with metformin was generally well tolerated.

Conclusion

Slight changes in AUC_inf, C_max and CL_R of metformin were observed when co-administered with peficitinib; however, these changes were considered not clinically relevant.

Electronic supplementary material

The online version of this article (10.1007/s00228-020-02876-2) contains supplementary material, which is available to authorized users.

Diabetes diagnosis from administrative claims and estimation of the true prevalence of diabetes among 4.2 million individuals of the Veneto region (North East Italy)

BACKGROUND AND AIMS

Diabetes can often remain undiagnosed or unregistered in administrative databases long after its onset, even when laboratory test results meet diagnostic criteria. In the present work, we analyse healthcare data of the Veneto Region, North East Italy, with the aims of: (i) developing an algorithm for the identification of diabetes from administrative claims (4,236,007 citizens), (ii) assessing its reliability by comparing its performance with the gold standard clinical diagnosis from a clinical database (7525 patients), (iii) combining the algorithm and the laboratory data of the regional Health Information Exchange (rHIE) system (543,520 subjects) to identify undiagnosed diabetes, and (iv) providing a credible estimate of the true prevalence of diabetes in Veneto.

METHODS AND RESULTS

The proposed algorithm for the identification of diabetes was fed by administrative data related to drug dispensations, outpatient visits, and hospitalisations. Evaluated against a clinical database, the algorithm achieved 95.7% sensitivity, 87.9% specificity, and 97.6% precision. To identify possible cases of undiagnosed diabetes, we applied standard diagnostic criteria to the laboratory test results of the subjects who, according to the algorithm, had no diabetes-related claims. Using a simplified probabilistic model, we corrected our claims-based estimate of known diabetes (6.17% prevalence; 261,303 cases) to account for undiagnosed cases, yielding an estimated total prevalence of 7.50%.

CONCLUSION

We herein validated an algorithm for the diagnosis of diabetes using administrative claims against the clinical diagnosis. Together with rHIE laboratory data, this allowed to identify possibly undiagnosed diabetes and estimate the true prevalence of diabetes in Veneto.

Prevalence of undiagnosed diabetes mellitus and associated factors among adult residents of Bahir Dar city, northwest Ethiopia: a community-based cross-sectional study

OBJECTIVE

To assess the prevalence of undiagnosed diabetes mellitus (DM) and associated factors among adult inhabitants of Bahir Dar city, northwest Ethiopia.

DESIGN

A community-based cross-sectional study was conducted on adults (n=607) of Bahir Dar city from 10 March to 20 May 2018.

MEASUREMENTS

Data were collected using structured interviewer-administered questionnaire, and anthropometric measurements were taken from each participant. Fasting blood sugar (FBS) level was determined by samples taken early in the morning and readings of FBS≥126 mg/dL were classified as diabetes. The multivariate logistic regression model was fitted to identify the predictors of undiagnosed DM; adjusted OR (AOR) with a 95% CI was computed to assess the strength of associations.

RESULT

The study revealed that the prevalence of undiagnosed DM was 10.2% with 95% CI 7.9 to 12.9. Ever checked blood glucose level (AOR=1.91, 95% CI 1.03 to 3.51), don't know the symptoms of diabetes (AOR=2.06, 95% CI 1.08 to 3.89), family history of DM (AOR=2.5, 95% CI 1.21 to 5.18) and body mass index (BMI) ≥25 kg/m² (AOR=1.98, 95% CI 1.09 to 3.60) were factors associated with undiagnosed DM.

CONCLUSION

The magnitude of undiagnosed diabetes was high. Family history of DM, ever checked blood glucose level, don't know about the symptoms of diabetes and overweight BMI were predictors of undiagnosed DM. Hence, screening and treatment are mandatory for high-risk groups. In addition, this study suggests frequent screening for those with family history and awareness creating about the disease for early detection and treatment.

A Population-level Analysis of the Differing Effects of Rheumatoid Arthritis and Spondyloarthritis on Peripartum Outcomes

OBJECTIVE

The effects of rheumatoid arthritis (RA) and spondyloarthritis (SpA) on maternal and neonatal outcomes at a population level have not previously been well compared.

METHODS

A contemporary pregnancy cohort of 312,081 women and corresponding birth events was assembled for the province of Alberta from the random selection of 1 live birth event per woman. We identified 3 groups: (1) no inflammatory arthritis (no IA, n = 308,989), (2) RA (n = 631), and (3) SpA (n = 2461). We compared maternal and neonatal outcomes, comorbid conditions, and medication use among the 3 groups. Multivariable logistic regression models evaluated the independent association between RA and SpA, relative to no IA, and the outcomes of small for gestation age (SGA) and hypertensive disorders during pregnancy.

RESULTS

Pregnant women with RA were significantly more likely to have preterm delivery (13.5%), cesarean delivery (33.9%), hypertensive disorders in pregnancy (10.5%), and SGA babies (15.6%), compared to pregnant women with either SpA or no IA. Nonsteroidal antiinflammatory drugs and corticosteroid use were significantly higher in pregnant women with RA compared to the other groups. Women with RA were significantly more likely to have an SGA baby (OR 1.51, 95% CI 1.21-1.88; p < 0.01), and hypertensive disorder in pregnancy (OR 1.51, 95% CI 1.16-1.97; p < 0.01), compared to women with no IA, while no difference was found between women with SpA and those with no IA.

CONCLUSION

Women with RA have a higher risk of worse maternal and neonatal outcomes, whereas the risk of these events is similar between women with and without SpA.

IL-1 inhibition improves insulin resistance and adipokines in rheumatoid arthritis patients with comorbid type 2 diabetes: An observational study

Recently, it has been shown that some well-known pathogenic mediators in rheumatoid arthritis (RA), such as interleukin-1β (IL-1β) and tumor necrosis factor (TNF), could play a pathogenic role in insulin resistance and (IR) and type 2 diabetes (T2D).In this 6-month longitudinal study, we aimed at investigating if the inhibition of IL-1 or TNF is associated with an improvement of IR in RA patients with comorbid T2D and the possible effects on selected serum adipokines. RA patients with comorbid T2D were recruited among those undergoing treatment with anakinra (ANA) or with TNF inhibitor (TNFi). The 1998-updated version of the Homeostasis Model Assessment (HOMA2) was used to calculate surrogate indexes of IR (HOMA2-IR) and steady-state beta cell function (%B) from fasting values of glucose and C-peptide. Glucagon, adiponectin, adipsin, leptin, and resistin were also measured. All these parameters were collected at baseline, after 3 and 6 months of treatment.ANA-treated patients showed a significant improvement in HOMA2-%β, HOMA2-IR, and glucagon. In TNFi-treated patients, no significant difference was observed analyzing these metabolic parameters. Adipsin and resistin decreased after 6 months in ANA-treated patients whereas, no difference was recognized analyzing adiponectin and leptin. In TNFi-treated patients, leptin and resistin significantly increased, whereas no difference was found analyzing adiponectin and adipsin, during the follow-up.Our data may suggest a beneficial effect of IL-1 inhibition on measures of metabolic derangement in RA-associated T2D. If further confirmed by larger studies, IL-1 targeting therapies may represent a tailored approach in these patients.

Tocilizumab, a Humanized Monoclonal Antibody Against the Interleukin-6 Receptor, Inhibits High Glucose-Induced Vascular Smooth Muscle Cell Migration Through Mitogen-Activated Protein Kinase Signaling Pathways

Rheumatoid arthritis (RA) with diabetes increases the risk of cardiovascular diseases. Interleukin-6 (IL-6) promotes the disease activity of RA and insulin resistance. This study aimed to evaluate the potential effects and molecular mechanisms of IL-6 blocker, tocilizumab, in atherosclerosis with diabetes. Human aortic smooth muscle cells (HASMCs) cultured under hyperglycemic conditions were evaluated for migration, expression of adhesion molecules, and matrix metalloproteinases before and after treatment with tocilizumab. High glucose (HG) significantly increased expression of IL-6, intercellular adhesion molecule (ICAM-1), matrix metalloproteinase-2 & 9, and migration of vascular smooth muscle cells. Tocilizumab suppressed HG-induced expression of ICAM-1, MMP-2, and MMP-9. Pretreatment with tocilizumab also inhibited migration, MAPK signaling, and nuclear translocation of p65-NF-κB in HG-stimulated HASMCs. Our data suggested that tocilizumab may exert an antiatherosclerotic activity in diabetes.

The effect of non-TNF-targeted biologics and small molecules on insulin resistance in inflammatory arthritis

Inflammatory arthritides are chronic diseases characterised by an increase in cardiovascular risk, largely attributable to the synergy between high-grade systemic inflammation and an elevated prevalence of traditional cardiovascular risk factors. Amongst the latter, insulin resistance and type 2 diabetes (T2D) play a key position. Previous studies demonstrated a potential insulin-sensitizing effect of anti-TNF biologic medications. For converse, less is known about the role of newer biologics or small molecules. For this reason, we performed a systematic review of the literature in order to identify the available data on the effect on insulin resistance of non-TNF targeting biologics and small molecules approved for the treatment of inflammatory arthritides. The search strategy initially retrieved 486 records of which only 10 articles were selected for inclusion in the final review. According to the available evidence, some of the newest molecules, in particular tocilizumab and abatacept, may have a role in improving insulin sensitivity; for converse, anakinra-mediated effect on glucose metabolism may exploit different facets of T2D pathophysiology, such as the preservation of beta-cell function. However, the data available on this issue are largely inconsistent and future, adequately designed studies are still needed to clarify the differential impact of novel therapeutics on individual pathophysiological features of T2D and other emerging cardiovascular risk factors.

Prevalence of glucose intolerance in rheumatoid arthritis patients at a tertiary care centre in Haryana

AIMS

Recent studies have shown increasing prevalence of dysglycemia in rheumatoid arthritis (RA) patients. The present study was planned to study the prevalence of pre-diabetes and diabetes in RA patients from a tertiary care centre in Haryana, India.

METHODS

150 diagnosed cases of rheumatoid arthritis which were on follow up in Rheumatology clinic from last one year and equal number of age, sex matched controls were recruited for the study. FPG, 2h plasma glucose level after 75g oral glucose tolerance test and HbA1c were estimated in all the subjects. In RA patients c-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) and Anti-cyclic citrullinated (Anti CCP) antibodies were also measured and disease activity was assessed by using (DAS28 joint counts) and CDAI.

RESULTS

Patients with RA had statistically significant higher waist circumference, hip circumference and BMI as compared to control group. Prevalence of glucose intolerance in RA patients and control group was 14.67% and 6.67% respectively which was statistically significant (p=0.025). The prevalence of pre-diabetes was in RA group was not significant statistically. There was higher disease activity in glucose intolerant (GI) RA cases as compared to normal glucose tolerant (NGT) RA cases. The most commonly used drug combination among RA patients was MTX+HCQ+SAAZ (49 patients, 32.67%). Maximum glucose intolerance was observed in patients who were on Non-HCQ drug combinations.

CONCLUSIONS

There is elevated prevalence of glucose intolerance among RA patients that is related to high disease activity, visceral adiposity and drugs usage.

Complement C3 and fatty liver disease in Rheumatoid arthritis patients: a cross-sectional study

BACKGROUND

Recent evidence suggested a potential role of complement fraction C3 as a biomarker of nonalcoholic fatty liver disease (NAFLD) in the general population. Aim of this study was to evaluate the performance of C3 for prediction of NAFLD in RA patients.

MATERIALS AND METHODS

For the present study, consecutive RA patients were recruited. NAFLD was diagnosed according to predefined ultrasonographic (US) criteria. For comparison, the hepatic steatosis index (HSI) was calculated.

RESULTS

Of 164 consecutive RA patients, 41 (25%) were diagnosed with NAFLD. The NAFLD group had a significant lower proportion of females (P = 0·04), higher BMI (P < 0·0001), C-reactive protein (P = 0·04), complement C3 (P = 0·001) and HSI (P = 0·003). In a logistic regression model, only male sex (OR 2·65, 95% CI: 1·08-6·50, P = 0·03), increasing BMI (OR 1·22, 95% CI: 1·02-1·46, P = 0·03) and complement C3 (OR 5·05, 95% CI: 1·06-23·93, P = 0·04) were associated with higher likelihood of being diagnosed with NAFLD. Finally, we built ROC curves for BMI, complement C3 and their combination for prediction of having NAFLD. The best cut-off for BMI was 28·5 kg/m² and yielded a sensitivity of 66% and a specificity of 71%; the best cut-off for complement C3 was 1·23 g/L and yielded a sensitivity of 76% and a specificity of 64% for classification of NAFLD cases.

CONCLUSIONS

Our results provide preliminary evidence for a potential role of complement C3 as a surrogate biomarker of NAFLD in RA patients.

Prevalence of type 2 diabetes and impaired fasting glucose in patients affected by rheumatoid arthritis: Results from a cross-sectional study

Although the better management of rheumatoid arthritis (RA) has significantly improved the long-term outcome of affected patients, a significant proportion of these may develop associated comorbidities including cardiometabolic complications. However, it must be pointed out that a comprehensive cardiometabolic evaluation is still poorly integrated into the management of RA patients, due to a limited awareness of the problem, a lack of appropriate clinical studies, and optimal strategies for cardiovascular (CV) risk reduction in RA. In addition, although several studies investigated the possible association between traditional CV risk factors and RA, conflicting results are still available.On this basis, we planned this cross-sectional study, aimed at investigating the prevalence of type 2 diabetes (T2D) and impaired fasting glucose (IFG) in RA patients compared with age- and gender- matched control individuals. Furthermore, we analyzed the role of both traditional and RA-related CV risk factors in predicting T2D and IFG.We observed an increased prevalence of T2D in RA patients when compared with age- and gender-matched controls. Regression analyses demonstrated that the presence of high blood pressure (HBP), a longer disease duration, and exposure to corticosteroids (CCS) were significantly associated with an increased likelihood of being classified as T2D. In addition, we observed an increased prevalence of IFG in RA patients when compared with age- and gender-matched controls. Regression analyses demonstrated that a higher body mass index (BMI), the presence of metabolic syndrome (MetS), higher levels of total cholesterol, the presence of radiographic damage, and higher serum levels of C-reactive protein (CRP) were significantly associated with an increased likelihood of presenting IFG.In this cross-sectional study, we observed an increased prevalence of T2D and IFG in an Italian cohort of RA patients when compared with age- and gender-matched control individuals. Interestingly, both RA-specific features, such as disease duration, CCS exposure, and radiographic damage, and traditional CV risk factors, such as HBP and MetS, were significantly associated with glucose metabolism abnormalities.

Anti-TNF-alpha agents and endothelial function in rheumatoid arthritis: a systematic review and meta-analysis

Rheumatoid arthritis (RA) has been associated with endothelial dysfunction, a pathophysiological feature of atherosclerosis. Our aim was to determine whether TNF-α blockade has a beneficial effect on endothelial function in RA. We performed a systematic review with meta-analysis to evaluate the effect of anti-TNF-α agents on endothelial function in RA patients. MedLine, Cochrane CENTRAL and SCOPUS were searched up to March 2016. Inclusion criteria were: 1) randomised controlled trial (RCT), quasi-RCT, before-after cohort study; 2) including RA patients; 3) treatment with anti-TNF-α medications; 4) evaluating the change from baseline in endothelial function. The search strategy retrieved 180 records, of which 20 studies were included in the systematic review. Pooled analysis using a random-effects model demonstrated a significant improvement in endothelial function following anti-TNF-α treatment (SDM 0.987, 95%CI [0.64–1.33], p < 0.0001). Generalisation of the results of the meta-analysis may be limited due to the presence of heterogeneity (I2 = 82.65%, p < 0.001) and evidence of possible publication bias. Meta-regression showed that endothelial function measurement technique was a significant contributor to heterogeneity. In conclusion, although limited by the methodological quality of the included studies, our meta-analysis suggests that anti-TNF-α treatment may improve endothelial function in RA patients.

Poor clinical response in rheumatoid arthritis is the main risk factor for diabetes development in the short-term: A 1-year, single-centre, longitudinal study

OBJECTIVES

Despite of the European League Against Rheumatism (EULAR) provided different sets of recommendations for the management of cardiovascular risk in inflammatory arthritis patients, it must be pointed out that cardiometabolic comorbidity, such as type 2 diabetes (T2D), remains still underdiagnosed and undertreated in patients affected by rheumatoid arthritis (RA).

METHODS

In this work, we designed a single centre, prospective study in order to better investigate the occurrence of T2D during the course of 1 year of follow-up. Furthermore, we evaluated the role of both traditional cardiovascular and RA-specific related risk factors to predict the occurrence of new T2D.

RESULTS

In this study, we evaluated 439 consecutive RA patients and we observed that 7.1% of our patients (31/439) developed T2D, after 12 month of prospective follow-up. The regression analysis showed that the presence of high blood pressure, the impaired fasting glucose (IFG) at the first observation and the poor EULAR-DAS28 response, after 12 months of follow-up, were significantly associated with an increased likelihood of being classified as T2D. Similarly, we observed that 7.7% of our patients (34/439) showed IFG after 12 months of prospective follow-up. The regression analysis showed that the presence of high blood pressure and the poor EULAR-DAS28 response after 12 months of follow-up, were significantly associated with an increased likelihood of showing IFG.

CONCLUSIONS

Our study supports the hypothesis of a significant short-term risk of T2D in RA patients and of a close associations between uncontrolled disease activity and glucose metabolism derangement. Further multicentre, randomised-controlled studies are surely needed in order to elucidate these findings and to better ascertain the possible contribution of different therapeutic regimens to reduce this risk.

Cardiovascular disease risk profiles in inflammatory joint disease entities

Background

Patients with inflammatory joint diseases (IJD) have increased risk of cardiovascular disease (CVD). Our aim was to compare CVD risk profiles in patients with IJD, including rheumatoid arthritis (RA), axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) and evaluate the future risk of CVD.

Methods

The prevalence and numbers of major CVD risk factors (CVD-RFs) (hypertension, elevated cholesterol, obesity, smoking, and diabetes mellitus) were estimated in patients with RA, axSpA and PsA. Relative and absolute risk of CVD according to Systematic Coronary Risk Evaluation (SCORE) was calculated.

Results

In total, 3791 patients were included. CVD was present in 274 patients (7.2%). Of those without established CVD; hypertension and elevated cholesterol were the most frequent CVD-RFs, occurring in 49.8% and 32.8% of patients. Patients with PsA were more often hypertensive and obese. Overall, 73.6% of patients had a minimum of one CVD-RF, which increased from 53.2% among patients aged 30 to <45 years, to 86.2% of patients aged 60 to ≤80 years. Most patients (93.5%) had low/moderate estimated risk of CVD according to SCORE. According to relative risk estimations, 35.2% and 24.7% of patients had two or three times risk or higher, respectively, compared to individuals with no CVD-RFs.

Conclusions

In this nationwide Norwegian project, we have shown for the first time that prevalence and numbers of CVD-RFs were relatively comparable across the three major IJD entities. Furthermore, estimated absolute CVD risk was low, but the relative risk of CVD was markedly high in patients with IJD. Our findings indicate the need for CVD risk assessment in all patients with IJD.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1358-1) contains supplementary material, which is available to authorized users.

Plantar fascia enthesopathy is highly prevalent in diabetic patients without peripheral neuropathy and correlates with retinopathy and impaired kidney function

BACKGROUND

Aim of this study was to evaluate the prevalence of plantar fascia (PF) enthesopathy in Type 2 diabetes mellitus (T2DM) patients without distal peripheral neuropathy (DPN).

METHODS

We recruited 50 T2DM patients without DPN and 50 healthy controls. DPN was excluded using the Michigan Neuropathy Screening Instrument (MNSI). All patients underwent a bilateral sonographicevaluation of the enthesealportion of the PF.

RESULTS

PF thickness was significantly higher in T2DM patients (p<0.0001). T2DM patients presented a higher prevalence of entheseal thickening (p = 0.002), enthesophyte (p = 0.02) and cortical irregularity (p = 0.02). The overall sum of abnormalities was higher in T2DM patients (p<0.0001), as was the percentage of bilateral involvement (p = 0.005). In a logistic regression analysis, retinopathy predicted entheseal thickening (OR 3.5, p = 0.05) and enthesophytes (OR 5.13, p = 0.001); reduced eGFR predicted enthesophytes (OR 2.93, p = 0.04); body mass index (BMI) predicted cortical irregularity (OR 0.87, p = 0.05); mean glucose predicted enthesophyte (OR 1.01, p = 0.03); LDL cholesterol predicted cortical irregularity (OR 0.98, p = 0.02).

CONCLUSIONS

Our data suggest that T2DM is associated with PF enthesopathyindependently of DPN.

High Prevalence of Achilles Tendon Enthesopathic Changes in Patients with Type 2 Diabetes Without Peripheral Neuropathy

BACKGROUND

Metabolic disorders are known to alter the mechanical properties of tendons. We sought to evaluate the prevalence of asymptomatic Achilles tendon enthesopathic changes in patients with type 2 diabetes mellitus (T2DM) without peripheral neuropathy.

METHODS

We recruited 43 patients with T2DM and 40 controls. Neuropathy was excluded with the Michigan Neuropathy Scoring Instrument. Bilateral ultrasonography of the Achilles tendon enthesis was performed.

RESULTS

Patients with T2DM had a higher prevalence of hypoechogenicity (26.7% versus 2.5%; P = .0001), entheseal thickening (24.4% versus 8.7%; P = .007), and enthesophytes (74.4% versus 57.5%; P = .02). No differences were found in the number of patients with erosions (1.2% versus 0%; P > .99), cortical irregularities (11.6% versus 3.7%; P = .09), bursitis (5.8% versus 3.7%; P = .72), or tears (2.3% versus 1.2%; P > .99). The mean ± SD sum of abnormalities was higher in patients with T2DM (1.5 ± 1.1 versus 0.7 ± 0.6; P < .0001), as was the percentage of bilateral involvement (72.1% versus 45.0%; P = .01). Mean ± SD thickness did not differ between patients and controls (4.4 ± 1.1 mm versus 4.2 ± 0.8 mm; P = .07).

CONCLUSIONS

According to our data, there is an elevated prevalence of asymptomatic Achilles tendon enthesopathic changes in patients with T2DM independent of peripheral neuropathy.

Prevalence of diabetes and unrecognized diabetes in hypertensive patients aged 40 to 79 years in southwest China

This study aimed to assess the prevalence of diabetes and unrecognized diabetes in hypertensive patients aged 40 to 79 years in Southwest China. From September 2013 to March 2014, a cross-sectional survey was conducted in 4021 hypertensive patients aged 40 to 79 years living in Chengdu and Chongqing, China. Fasting plasma glucose (FPG) and 2h plasma glucose (2-hPG) in an oral glucose-tolerance test (OGTT) were used for assessments. Whether the patients previously had diabetes (DM) was determined by their own reports. The survey was carried out by the same questionnaire for all respondents. DM prevalence was 32.0% in hypertensive patients aged 40 to 79 years in Southwest China, with the rates of 29.6% and 33.5% in men and women, respectively (P<0.001). DM prevalence increased with age age and body-mass index. DM prevalence rates were 16.9%, 24.7%, 38.2% and 41.9% in hypertensive patients aged 40-49, 50-59, 60-69 and over 70, respectively. DM prevalence were 30.6%, 27.9%, 37.1%, and 37.4%, for BMI<18.5, 18.5-24.9, 25.0-29.9, and ≥30, respectively. Prevalence of unrecognized DM were 20.8% in hypertensive patients aged 40 to 79 years in Southwest China. Using only fasting blood glucose testing without OGTT would have resulted in 65.0% of missed DM diagnosis in these newly diagnosed patients. The prevalence of DM and unrecognized DM were high in hypertensive patients aged 40 to 79 years in Southwest China.These findings indicate that hypertensive patients aged 40 to 79 years should regularly submit to community-based OGTT screening for timely DM diagnosis.

Evaluation of Audiometric Test Results to Determine Hearing Impairment in Patients with Rheumatoid Arthritis: Analysis of Data from the Korean National Health and Nutrition Examination Survey

This study aimed to evaluate the association between rheumatoid arthritis (RA) and hearing impairment in the Korean adult population. Audiometric and laboratory test data from the 2010–2012 Korean National Health and Nutrition Examination Survey (KNHANES) were used for analysis. The relationship between RA and hearing impairment was analyzed, adjusting for various known risk factors associated with hearing impairment. RA was defined in the questionnaire as “RA diagnosed by a physician (yes/no) through a standardized interview.” We defined hearing impairment according to 2 categories of frequency (low/mid and high) as follows (average values in kHz): low/mid frequency, 0.5, 1.0, and 2.0, and high frequency, 3.0, 4.0, and 6.0. Of the subjects, 15,158 (weighted n = 32,035,996) completed the audiometric tests. The overall weighted prevalence of RA was 1.5%. The prevalence of hearing impairment was higher in the subjects with RA than in those without RA, in both, the low/mid- and high-frequency categories (21.1% vs 7.5%, p < 0.001 and 43.3% vs. 26.2%, p < 0.001, respectively). In the multivariable logistic analysis, RA (odds ratios [OR] 1.47, 95% confidence interval [CI] 1.05–2.06, p = 0.025) was an independent risk factor of low/mid-frequency hearing impairment along with age (OR 1.12, 95% CI 1.12–1.13, p < 0.001), current smoking (OR 1.27, 95% CI 1.03–1.56, p = 0.026), and college graduation (OR 0.53, 95% CI 0.39–0.72, p < 0.001). In the multivariable analysis of high-frequency hearing impairment, RA did not show any association with hearing impairment. This study suggests that RA is associated with low/mid-frequency hearing impairment after adjustment for various known risk factors. Further study is needed to verify the hearing impairment in RA.

Complement C3 Is the Strongest Predictor of Whole-Body Insulin Sensitivity in Psoriatic Arthritis

Objectives

To evaluate the correlation between inflammatory measures and whole-body insulin sensitivity in psoriatic arthritis (PsA) patients.

Methods

For the present study, 40 nondiabetic PsA patients were recruited. A standard oral glucose tolerance test (OGTT) was performed. The insulin sensitivity index (ISI), insulinogenic index (IGI) and oral disposition index (ODI) were calculated from dynamic values of glucose and insulin obtained during OGTT.

Results

In our study population, mean ISI was 3.5 ± 2.5, median IGI was 1.2 (0.7–1.8), mean ODI 4.5 ± 4.5. In univariate correlation analysis, ISI correlated inversely with systolic blood pressure (sBP) (R = -0.52, p = 0.001), diastolic blood pressure (dBP) (R = -0.45, p = 0.004) and complement C3 (R = -0.43, p = 0.006) and ODI correlated inversely with sBP (R = -0.38, p = 0.02), dBP (R = -0.35, p = 0.03) and complement C3 (R = -0.37, p = 0.02). No significant correlations were found between analyzed variables and IGI. In a stepwise multiple regression, only complement C3 entered in the regression equation and accounted for approximately 50% of the variance of ISI. Using a receiver operating characteristic (ROC) curve we identified the best cut-off for complement C3 of 1.32 g/L that yielded a sensitivity of 56% and a specificity of 96% for classification of insulin resistant patients.

Conclusions

In conclusion, our data suggest that serum complement C3 could represent a useful marker of whole-body insulin sensitivity in PsA patients.

A Combination of CD28 (rs1980422) and IRF5 (rs10488631) Polymorphisms Is Associated with Seropositivity in Rheumatoid Arthritis: A Case Control Study

Introduction

The aim of the study was to analyse genetic architecture of RA by utilizing multiparametric statistical methods such as linear discriminant analysis (LDA) and redundancy analysis (RDA).

Methods

A total of 1393 volunteers, 499 patients with RA and 894 healthy controls were included in the study. The presence of shared epitope (SE) in HLA-DRB1 and 11 SNPs (PTPN22 C/T (rs2476601), STAT4 G/T (rs7574865), CTLA4 A/G (rs3087243), TRAF1/C5 A/G (rs3761847), IRF5 T/C (rs10488631), TNFAIP3 C/T (rs5029937), AFF3 A/T (rs11676922), PADI4 C/T (rs2240340), CD28 T/C (rs1980422), CSK G/A (rs34933034) and FCGR3A A/C (rs396991), rheumatoid factor (RF), anti–citrullinated protein antibodies (ACPA) and clinical status was analysed using the LDA and RDA.

Results

HLA-DRB1, PTPN22, STAT4, IRF5 and PADI4 significantly discriminated between RA patients and healthy controls in LDA. The correlation between RA diagnosis and the explanatory variables in the model was 0.328 (Trace = 0.107; F = 13.715; P = 0.0002). The risk variants of IRF5 and CD28 genes were found to be common determinants for seropositivity in RDA, while positivity of RF alone was associated with the CTLA4 risk variant in heterozygous form. The correlation between serologic status and genetic determinants on the 1st ordinal axis was 0.468, and 0.145 on the 2nd one (Trace = 0.179; F = 6.135; P = 0.001). The risk alleles in AFF3 gene together with the presence of ACPA were associated with higher clinical severity of RA.

Conclusions

The association among multiple risk variants related to T cell receptor signalling with seropositivity may play an important role in distinct clinical phenotypes of RA. Our study demonstrates that multiparametric analyses represent a powerful tool for investigation of mutual relationships of potential risk factors in complex diseases such as RA.