Women, men, and rheumatoid arthritis: analyses of disease activity, disease characteristics, and treatments in the QUEST-RA study

Biologics or Janus Kinase Inhibitors in Rheumatoid Arthritis Patients Who are Insufficient Responders to Conventional Anti-Rheumatic Drugs

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease which can induce progressive disability if not properly treated early. Over the last 20 years, the improvement of knowledge on the pathogenesis of the disease has made available several drugs targeting key elements of the pathogenetic process, which now represent the preferred treatment option after the failure of first-line therapy with conventional drugs such as methotrexate (MTX). To this category of targeted drugs belong anti-cytokine or cell-targeted biological agents and more recently also Janus kinase inhibitors (JAKis). In the absence to date of specific biomarkers to guide the therapeutic choice in the context of true precision medicine, the choice of the first targeted drug after MTX failure is guided by treatment cost (especially after the marketing of biosimilar products) and by the clinical characteristics of the patient (age, sex, comorbidities and compliance) and the disease (presence or absence of autoantibodies and systemic or extra-articular manifestations), which may influence the efficacy and safety profile of the available products. This viewpoint focuses on the decision-making process underlying the personalized approach to RA therapy and will analyse the evidence in the literature supporting the choice of individual products and in particular the differential choice between biological drugs and JAKis.

Association between Life's Essential 8 and rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) exhibits a robust association with cardiovascular disease. Our study aims to elucidate the correlation between RA prevalence and Life's Essential 8 (LE8), a recently updated measure of cardiovascular health (CVH).

METHODS AND RESULTS

We conducted a population-based cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2018. Utilizing multivariable logistic and restricted cubic spline models, we explored the relationship between LE8 and RA. Our analysis included 17,263 participants. We found that higher LE8 scores were closely associated with reduced odds of RA (odds ratio for each 10-point increase, 0.91 (95% CI, 0.75-0.87)). Furthermore, we observed a nonlinear association between LE8 and RA after adjusting for potential confounders. Specifically, higher scores for sleep health, nicotine exposure, body mass index, and blood pressure within the LE8 components were significantly correlated with a lower risk of RA. Additionally, the inverse relationship between LE8 scores and RA was notably stronger among young and female individuals.

CONCLUSION

Our findings suggest a negative correlation between LE8 and RA prevalence, indicating that adherence to the lifestyle defined by LE8 may confer protective effects against RA.

Associations of gender with sexual functioning, loneliness, depression, fatigue and physical function amongst patients suffering from rheumatoid arthritis with a particular focus on methotrexate usage

There is a lack of knowledge regarding methotrexate (MTX) usage in patients with rheumatoid arthritis (RA) and its possible links with gender, disease characterization and sexual functioning, loneliness, fatigue and depression. We, therefore, investigated the associations of gender with physical function, fatigue, depression, loneliness and sexual functioning with a particular focus on MTX usage. A cross-sectional study design was used. Inclusion criteria were RA diagnosis, age above 18 years and available data on MTX treatment 1 year after diagnosis. Data consisted of responses from validated questionnaires regarding physical function, fatigue, depression, loneliness and sexual functioning combined with evaluations from medical records. Data were analysed with linear regression models comparing numerical outcome measures between male and female patients and between MTX users and MTX non-users. Amongst 286 patients with RA (69 men and 217 women), 67.8% were MTX users 1 year after diagnosis. Comparing women and men, both overall and within subgroups of MTX usage, we found significantly more adverse outcomes for women than men in physical functioning at diagnosis and in sexual function, depression, fatigue and physical functioning at enrolment in the study. Gender differences were also present when comparing MTX users with MTX non-users divided by gender. There were only significant differences in the HAQ and loneliness scores when comparing MTX users with MTX non-users. Women with RA had more negative outcomes measured by the selected PROMs compared to men with RA, both overall and in subgroups of users and non-users of MTX. These findings call for sharpened attention to the importance of gender in the treatment and care of patients with RA, as well as in future clinical research.

The steroid-sparing effect of JAK inhibitors across multiple patient populations

Introduction

JAK-inhibitors (JAK-i) represent an effective treatment in Rheumatoid Arthritis (RA) and Psoriatic Arthritis (PsA). Oral glucocorticoids (OGC) are commonly used in combination with JAK-i to reach therapeutic target. We aimed to assess, in a real-life setting, the reduction of OGC dose during JAK-i treatment in active RA and PsA patients.

Methods

We prospectively enrolled 103 patients (88 RA, 15 PsA) treated with JAK-i: 24% bio-naïve (b-naïve), 76% bDMARD-insufficient responders (bDMARD-IR) and 40% difficult to treat (D2T), defined as failure of ≥2 bDMARDs with different mechanism of action. Disease activity (DAS28 and DAPSA, VAS-pain, GH) and OGC dose was collected at baseline and after 3, 6 and 12 months (T3, T6, T12) of treatment.

Results

In all the cohort and in b-naïve patients we reported a reduction of OGC dose at all time-points; bDMARD-IR patients were able to reduce OGC dose at T3 and T12; D2T ones only at T3. We reported an improvement of disease activity and withdrawal of OGC as early as three months of therapy, at all time-points, regardless of line of bDMARD treatment.

Conclusion

Chronic OGC may cause detrimental bone, metabolic, cardiovascular side effects and infections; therefore JAK-i steroid-sparing effect may be beneficial for patients in long-term treatment.

Sex bias in immune response: it is time to include the sex variable in studies of autoimmune rheumatic diseases

Healthy females and males differ in their immune cell composition and function and females generally mount stronger immune response than males and are much more susceptible to autoimmune rheumatic diseases. Females differ from males in sex hormones, and X-chromosome genes. Sex hormones affect immune cells and responses, and may induce epigenetic DNA changes. The importance of X-chromosome genes is exemplified in men with the Klinefelter syndrome (47,XXY) who have an additional X-chromosome and develop systemic lupus erythematosus(SLE) as frequently as women. X-chromosome contains genes critical for the immune response, such as FOXP3, toll-like receptor(TLR)7, TLR8, CD40 Ligand, IL2RG, IL9R, BTK, and others. Whereas one X-chromosome in females is randomly inactivated early in embryonic development, around 25% of X-linked genes escape inactivation and result in more X-linked gene dosage in females. We use two key female-biased autoimmune rheumatic diseases, SLE and systemic sclerosis, to review differences in immune response, and clinical manifestations between females and males. The inclusion of sex variable in research will facilitate precision medicine and optimal patient outcome.

National burden of rheumatoid arthritis in Canada, 1990-2019: findings from the Global Burden of Disease Study 2019 - a GBD collaborator-led study

OBJECTIVE

The objectives of this study were: (1) to describe burden of rheumatoid arthritis (RA) and trends from 1990 to 2019 using the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) data, (2) to describe age and sex differences in RA and (3) to compare Canada's RA burden to that of other countries.

METHODS

Disease burden indicators included prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs) and disability-adjusted life-years (DALYs). GBD estimated fatal and non-fatal outcomes using published literature, survey data and health insurance claims. Data were analysed by Bayesian meta-regression, cause of death ensemble model and other statistical methods. DALYs for Canada were compared with DALYs of countries with similarly high Socio-Demographic Index values.

RESULTS

In Canada, the RA prevalence rate increased by 27% between 1990 and 2019, mortality rate decreased by 27%, YLL rate decreased by 30%, YLD increased by 27% and DALY rate increased by 13%, all age standardised. The decline in RA mortality and YLL rates was especially pronounced after 2002. The disease burden was higher in females for all indicators, and DALY rates were higher among older age groups, peaking at age 75-79 years. Prevalence and DALYs were higher in Canada compared with global rates.

CONCLUSION

Trends in RA burden indicators over time and differences by age and sex have important implications for Canadian policy-makers, researchers and care providers. Early identification and management of RA in women may help reduce the overall burden of RA in Canada.

High-grade synovitis associates with clinical markers and response to therapy in chronic inflammatory arthritis: post hoc analysis of a synovial biomarkers prospective cohort study

Background

Inflammatory arthritis (IAs), such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA), are characterized by the presence of chronic synovitis. The Krenn's synovitis score (KSS), a simple tool detectable by haematoxylin/eosin staining of synovial biopsy samples, allows the discrimination between high-grade and low-grade synovitis. The aim of this study was to identify the clinical associations of KSS and to evaluate the relationship between high-grade synovitis and treatment response in IA patients.

Methods

Clinical, laboratory and ultrasound data were retrieved from RA and PsA patients recruited in the prospective MATRIX cohort study. Inclusion criteria were age≥18 years, RA or PsA diagnosis, and presence of active disease with eligibility to start/modify therapy. Patients underwent ultrasound-guided synovial biopsy of one of the most involved joints before starting/modifying treatment according to treat-to-target strategy. The samples were analysed by an expert pathologist for KSS calculation. Univariable and multivariable logistic regression analyses were performed to evaluate the relationship between KSS and baseline variables. The association between KSS and treatment response at 24 weeks of follow-up was investigated in univariable logistic regression analysis.

Results

53 patients, 34 RA and 19 PsA, completed 24 weeks of follow-up after synovial biopsy. Patients were either treatment naïve (N=6, 11%), csDMARDs-experienced (N=46, 87%) or b/tsDMARDs-experienced (N=20, 38%). Median KSS was 6.00 (Q1-Q3 4.00-7.00) in RA and 4.00 (3.00-6.00) in PsA (p=0.040), and inflammatory infiltrates score was significantly higher in RA than in PsA patients (median 3.00 vs 2.00, p=0.021). In multivariable analysis, synovial effusion in the biopsied joint (OR 9.26, 95%CI 2.12-53.91) and erythrocyte sedimentation rate (ESR) (OR 1.04, 95%CI 1.01-1.08) associated with high KSS. High-grade synovitis significantly associated with a higher probability of achieving DAS28 remission, ACR20/50 response, and Boolean2.0 remission, independently from diagnosis.

Conclusion

Several markers of pro-inflammatory pathways associated with the presence of high-grade synovitis, and patients with higher KSS shared a higher probability of treatment targets achievement in the follow up. The integration of a simple and feasible tool like KSS in the clinical and prognostic stratification of patients with IA might help in intercepting patients with a disease more prone to respond to available treatment paradigms.

Hormonal and reproductive factors in relation to the risk of rheumatoid arthritis in women: a prospective cohort study with 223 526 participants

OBJECTIVE

This study aimed to examine rheumatoid arthritis (RA) risk associated with hormonal and reproductive factors in women from the large cohort of the UK Biobank.

METHODS

Data on hormonal and reproductive factors in women were collected from a prospective cohort of 223 526 UK Biobank participants. The potential relationship between reproductive factors and RA risk was assessed using restricted cubic spline. Hazard ratios (HR) were estimated using Cox proportional hazard regressions.

RESULTS

During a median follow-up of 12.39 years, 3313 women with RA were identified. Age at menarche >14 years was associated with a greater RA risk (HR 1.13, 95% CI 1.02 to 1.26) compared with menarche at 13. The multiple adjusted HR for RA in women with menopause at <45 years was 1.46. Reproductive years <33 increased the risk of RA (HR 1.39, 95% CI 1.21 to 1.59). Compared with those with 2 children, women with ≥4 children were associated with a higher risk of RA (HR 1.18, 95% CI 1.04 to 1.34). Women who had a hysterectomy (HR 1.40, 95% CI 1.25 to 1.56) or oophorectomy (HR 1.21, 95% CI 1.08 to 1.35) had a higher risk of RA than those without a hysterectomy or oophorectomy. Both hormone replacement therapy (HRT) use (HR 1.46, 95% CI 1.35 to 1.57) and HRT duration (HR 1.02, 95% CI 1.01 to 1.03) were associated with a higher risk of RA.

CONCLUSIONS

Some hormonal and reproductive factors were associated with a higher risk of RA. Hormonal and reproductive factors should be considered in risk assessment and formulating management plans in female patients with RA.

Osteoporosis-related fractures in men and women with established and early rheumatoid arthritis: predictors and risk compared with the general population

OBJECTIVES

To study the risk of osteoporosis-related fractures in a community-based sample of men and women with rheumatoid arthritis (RA) overall, as well as early (< 1 year of disease duration, follow-up time maximum 10 years) and established (RA diagnosis since ≥ 5 years on July 1, 1997) RA, compared with the general population. To study potential risk factors for fractures in patients with RA from baseline questionnaire data.

METHODS

A community-based cohort of patients with RA (n = 1928) was studied and compared to matched general population controls. Information on osteoporosis-related fractures (hip, proximal upper arm, distal forearm and vertebral fractures) during the period July 1, 1997 to December 31, 2017 was obtained by linkage to the Swedish National Inpatient Register and the Cause of Death Register. The incidence of fractures was estimated in patients and controls. Cox regression models were used to assess the relation between RA and the risk of fractures and to assess potential predictors of fractures in RA patients. Analyses were stratified by sex, and performed in all patients with RA, and in subsets with early and established RA.

RESULTS

The overall incidence of osteoporosis-related fractures in the RA cohort was 10.6 per 1000 person-years (95% CI 9.31; 12.0). There was an increased risk of fractures overall in both men (hazard ratio (HR) 1.55, 95% CI 1.03; 2.34) and women (HR 1.52; 95% CI 1.27; 1.83) with RA compared to controls, with significantly increased risk also in the hip. No increased risk of osteoporosis-related fractures overall was seen in patients with early RA (HR 1.01, 95% CI 0.69; 1.49). Higher age, longer duration of RA, higher HAQ scores and higher scores in the visual analogue scale for global health were predictors of fractures.

CONCLUSION

Both men and women with RA were at increased risk of osteoporosis-related fractures. Patients with early RA did not have significantly increased risk during the first 10 years of disease in this study.

The association between CYB5A gene rs1790834 polymorphism and clinical improvement after 6 months of leflunomide treatment in women with rheumatoid arthritis

INTRODUCTION/OBJECTIVES

Rheumatoid arthritis (RA) is a disease affecting around 1% of the population in developed countries and can be treated with leflunomide. The higher prevalence of RA among women and numerous previous studies suggested the crucial role of sex hormones. Cytochrome CYB5A regulates the synthesis of androgens. Therefore, the aim of this study was to determine the association between common CYB5A gene polymorphism and the response to leflunomide in women with RA.

METHODS

This study included 111 patients. All of them received oral leflunomide monotherapy at a dose of 20 mg daily. Women were genotyped for the presence of CYB5A rs1790834 polymorphism and evaluated monthly for 6 months following the initiation of treatment.

RESULTS

After 6 months of therapy, patients with the GG genotype had higher DAS28 values and less improvement in DAS28 compared to patients with the GA and AA genotypes (p = 0.04). No statistically significant differences were found in relation to other disease activity parameters.

CONCLUSIONS

The results of the current study suggest a possible association of the CYB5A rs1790834 polymorphism with some disease activity parameters in RA patients treated with leflunomide during the initial therapy period. However, confirmation of the effect of this polymorphism on the efficacy of leflunomide treatment requires further studies. Key Points • Leflunomide is the synthetic disease-modifying anti-rheumatic drug used in the therapy of rheumatoid arthritis. • CYB5A rs1790834 gene polymorphism may influence the clinical improvement after 6 months of leflunomide treatment in women with rheumatoid arthritis.

Impact of adverse drug reactions on the treatment pathways of early rheumatoid arthritis patients: a prospective observational cohort study

BACKGROUND

Several patient characteristics may be of influence on treatment pathways of rheumatoid arthritis (RA) patients in clinical practice. The aim of this study is to analyze treatment pathways of early RA patients stratified for gender and adverse drug reaction (ADR) occurrence.

RESEARCH DESIGN AND METHODS

Treatment pathways of patients included in the DREAM-RA treat-to-target cohort I between 16th of July 2006-30th of April 2020 were assessed. Treatment pathways were visualized in Sankey diagrams. Follow-up time, duration per treatment and the number of treatments received were stratified for gender and ADR occurrence and analyzed. Independent t-tests and chi-square tests were performed where applicable.

RESULTS

Treatment pathways of 372 patients (follow-up: 2488.4 years, mean 6.7 ± 3.7 years) were analyzed. The Sankey diagrams visualize that treatment pathways became increasingly varied and complex over time. No significant differences were found when comparing female patients and male patients. However, the average treatment duration was shorter in patients with ADRs (1.8 vs. 2.7 years, p < 0.05), and the number of treatments higher (3.5 vs. 2.5, p < 0.05).

CONCLUSIONS

Treatment pathways increase in complexity over time. Differences were found between patients with and without ADRs, with patients that experience ADRs receiving more and shorter treatments.

Sex differences in long-term effects of collagen-induced arthritis in middle-aged mice

Introduction: Rheumatoid arthritis (RA) is a chronic inflammatory disorder with high prevalence among middle-aged women. Collagen-induced arthritis (CIA) is the most widely used animal model of RA, however, sex differences and long-term effects of CIA in mice are poorly described in the literature. Aim: Therefore, the present study aimed to analyze the long-term effects of CIA on the joints of middle-aged mice of both sexes and to describe potential sex differences. Materials and methods: CIA was induced in middle-aged DBA/1J mice by immunization with bovine type II collagen and complete Freund's adjuvant. Saline was administered to control mice. Arthritis score assessment, plethysmometry, and thermal imaging of the joints were performed weekly for 15 weeks. Locomotor activity, micro-computed tomography, joint histology and biochemical analyses were performed at the end of the experiment. Results: Our results indicate a similar prevalence of arthritis in both sexes of mice-67% (8/12) of females and 89% (8/9) males with an earlier onset in males (day 14 vs. day 35). After the arthritis scores peaked on day 56 for males and day 63 for females, they steadily declined until the end of the experiment on day 105. A similar dynamics was observed in paw volume and temperature analyzing different aspects of joint inflammation. Long-term consequences including higher proteinuria (by 116%), loss of bone density (by 33.5%) and joint damage in terms of synovial hyperplasia as well as bone and cartilage erosions were more severe in CIA males compared to CIA females. There were no significant differences in locomotor activity between CIA mice and CTRL mice of any sex. Conclusion: This is the first study to describe the long-term effects of the CIA model in terms of sex differences in DBA/1J mice. Our results indicate sex differences in the dynamics, but not in the extent of arthritis. An earlier onset of arthritis and more severe consequences on joints, bones and kidneys were found in males. The underlying immune pathomechanisms responsible for the limited duration of the arthritis symptoms and the opposite sex difference in comparison to RA patients require further investigation.

Sex and age do not modify the association between glucocorticoids and bone mineral density in patients with rheumatoid arthritis: a cross-sectional study

BACKGROUND

It is unclear whether sex or age modify the association of glucocorticoid (GC) use with reduced bone mineral density (BMD) in patients with rheumatoid arthritis (RA).

METHODS

We studied cross-sectional data of RA patients with current or previous GC treatment in a single center cohort study (Rh-GIOP cohort). Our primary outcome was the minimum T-score (measured by DXA) of either lumbar spine, total femur, or femoral neck. Current GC dose was the main exposure; cumulative GC dose and cumulative duration of GC use were also assessed. Following a predefined statistical analysis plan, linear regression analyses with adjustment for confounders assessed whether the association of GC use with BMD was modified by sex (men versus women) or age (≥ 65 versus < 65 years).

RESULTS

Four hundred eighty-three patients with RA (mean age 64 ± 12 years, 80% women) were included. 33% were not currently taking GCs, 32% were treated with a dose of 5 mg/d prednisone equivalent and 11% with more than 7.5 mg/d. 23% of patients had osteoporosis by DXA (minimum T-score ≤ -2.5). The slope, i.e., the association between changes in minimum T-scores with 1 mg/d change in current GC dose, was similar in men and women (-0.07 and -0.04, respectively; difference -0.03 [-0.11 to 0.04]; p for interaction = 0.41). Slopes were also similar for elderly and non-elderly patients (-0.03 and -0.04, respectively; difference -0.01 [-0.06 to 0.05]; p for interaction = 0.77). Using cumulative dose and duration of use as exposures did not lead to substantial changes of these results.

CONCLUSIONS

In our sample, the association of GC use with reduced BMD in RA was not modified by sex or age.

Comprehensive evaluation of the influence of sex differences on composite disease activity indices for rheumatoid arthritis: results from a nationwide observational cohort study

BACKGROUND

The effects and their magnitudes of sex on disease activity indices for rheumatoid arthritis are not clear. We aimed to comprehensively evaluate the influence of sex on disease activity indices in the real-world setting using a large observational database.

METHODS

We analyzed 14,958 patients registered in the National Database of Rheumatic Diseases in Japan (NinJa) in 2017. We evaluated the sex differences in the 28-joint disease activity score (DAS28) using erythrocyte sedimentation rate (ESR), DAS28 using C-reactive protein (DAS28-CRP), Simplified Disease Activity Index (SDAI), and Clinical Disease Activity Index by disease activity category using Cliff's delta and regression analysis. Differences in the share of components of indices were evaluated using permutational multivariate analysis of variance. Correction equations were constructed to estimate the number of misclassification in male patients who achieve DAS28-ESR remission.

RESULTS

DAS28-ESR showed higher values in female patients than male patients in remission despite no obvious difference in other indices or disease activity categories. Among the components of DAS28-ESR, only ESR was higher in female patients than male patients in remission. In DAS28-CRP and SDAI, 28-tender joint count was higher and CRP was lower in female patients than male patients. In addition, the profiles in the components were different between female and male patients, especially among those with high disease activity. Using correction equations, almost 12% of male patients with DAS28-ESR remission were estimated to be misclassified, mainly due to differences in ESR.

CONCLUSION

Among the disease activity indices, significant sex difference was observed only in DAS28-ESR remission. The degree of misclassification in DAS28-ESR remission would be unignorable.

Sex differences in the efficacy, safety and persistence of patients with psoriatic arthritis treated with tofacitinib: a post-hoc analysis of phase 3 trials and long-term extension

BACKGROUND

Evaluate the impact of sex on tofacitinib efficacy, safety and persistence (time to discontinuation) in patients with psoriatic arthritis (PsA).

METHODS

Data were pooled from two phase 3 randomised controlled trials. Patients were randomised to tofacitinib 5 mg or 10 mg two times per day, adalimumab 40 mg every 2 weeks or placebo. Efficacy outcomes to month 12 included American College of Rheumatology (ACR)20/50/70, minimal disease activity (MDA), Psoriasis Area Severity Index (PASI)75, change from baseline (∆) in Health Assessment Questionnaire-Disability Index (HAQ-DI) and ∆Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F). Safety was assessed to month 12 and persistence was assessed to month 42 of a long-term extension study.

RESULTS

Overall, 816 patients were included (54.3% females). At baseline, higher tender joint counts, enthesitis scores and worse HAQ-DI and FACIT-F were reported in females versus males; presence of dactylitis and PASI were greater in males versus females. At month 3, tofacitinib efficacy generally exceeded placebo in both sexes. Overall, similar ACR20/50/70, PASI75, ∆HAQ-DI and ∆FACIT-F were observed for tofacitinib between sexes; females were less likely to achieve MDA. Similar proportions of males/females receiving tofacitinib (both doses) experienced treatment-emergent adverse events (AEs). Serious AEs occurred in 3.4%/6.6% and 4.0%/5.9% males/females with tofacitinib 5 mg and 10 mg two times per day. Persistence was generally similar between sexes.

CONCLUSION

Tofacitinib efficacy exceeded placebo in both sexes and was comparable between sexes. Consistent with previous studies of PsA treatments, females were less likely to achieve MDA, likely due to baseline differences. Safety and time to discontinuation were generally similar between sexes.

TRIAL REGISTRATION NUMBER

NCT01877668; NCT01882439; NCT01976364.

Representation of adults with rheumatoid arthritis in US-based randomized controlled exercise trials: a systematic review with meta-analysis

The purpose of this study was to conduct a systematic review with meta-analysis to determine the representation of adults with rheumatoid arthritis (RA) according to sex, race, and ethnicity in exercise randomized controlled trials (RCTs) conducted in the USA. Exercise RCTs ≥ 4 weeks conducted in the USA in adults ≥ 18 years with RA were eligible. Studies were retrieved by searching six electronic databases, cross-referencing and searching a clinical trials registry. Dual, independent, study selection and data abstraction were conducted. The primary outcomes were the proportion of participants in each study according to sex as well as race/ethnicity. Results were pooled meta-analytically using the inverse-variance heterogeneity (IVhet) model after applying the double-arcsine transformation. Of the 1030 unique articles screened, five RCTs representing 353 participants with RA were included. The pooled participant prevalence was 83% (95% CI = 73 to 92%) for women and 17% (95% CI = 8 to 27%) for men, suggesting an over-representation of women and an under-representation of men by approximately 7.4% based on current prevalence US estimates for each. Qualitative examination for race and ethnicity demonstrated an under-representation of racial/ethnic minority groups. There is a lack of representation of men with RA in US-based randomized controlled exercise intervention studies. Additional US-based randomized controlled exercise trials, including greater inclusion and reporting of the racial/ethnic composition of participants, are also needed. Key Points • This systematic review with meta-analysis of US studies found an under-representation of men in randomized controlled trials examining the effects of exercise in those with rheumatoid arthritis (RA). • Qualitative examination according to race/ethnicity found both a lack of reporting as well as under-representation of selected racial/ethnic minorities in US-based randomized controlled exercise studies among adults with RA. • This study highlights the need for additional US-based randomized controlled trials of exercise in adults with RA that better represent the RA population in the USA.

Lower odds of remission among women with rheumatoid arthritis: A cohort study in the Swiss Clinical Quality Management cohort

OBJECTIVE

To compare the likelihood of achieving remission between men and women with rheumatoid arthritis (RA) after starting their first biologic or targeted synthetic disease-modifying anti-rheumatic drug (b/tsDMARD).

METHODS

This cohort study in the Swiss Clinical Quality Management in Rheumatic Diseases (SCQM) registry included RA patients starting their first b/tsDMARD (1997-31/04/2018). The odds of achieving remission at ≤12-months, defined by disease activity score 28-joints (DAS28) <2.6, were compared between men and women. Secondary analyses were adjusted for age and seropositivity, and we investigated potential mediators or factors that could explain the main findings.

RESULTS

The study included 2839 (76.3%) women and 883 (23.7%) men with RA. Compared to women, men were older at diagnosis and b/tsDMARD start, but had shorter time from diagnosis to b/tsDMARD (3.4 versus 5.0 years, p<0.001), and they had lower DAS28 at b/tsDMARD start. Compared to women, men had 21% increased odds of achieving DAS28-remission, with odds ratio (OR) 1.21, 95% confidence interval (CI) 1.02-1.42. Adjusting for age and seropositivity yielded similar findings (adjusted OR 1.24, 95%CI 1.05-1.46). Analyses of potential mediators suggested that the observed effect may be explained by the shorter disease duration and lower DAS28 at treatment initiation in men versus women.

CONCLUSION

Men started b/tsDMARD earlier than women, particularly regarding disease duration and disease activity (DAS28), and had higher odds of reaching remission. This highlights the importance of early initiation of second line treatments, and suggests to target an earlier stage of disease in women to match the benefits observed in men.

Clinical Factors and the Outcome of Treatment with Methotrexate in Rheumatoid Arthritis: Role of Rheumatoid Factor, Erosive Disease and High Level of Erythrocyte Sedimentation Rate

To identify the clinical factors predicting the outcome of treatment with methotrexate in rheumatoid arthritis, we examined 312 patients (253 females, 59 males) with rheumatoid arthritis diagnosed according to the criteria of the American College of Rheumatology. All patients included in this analysis began treatment with a regimen of oral MTX 7.5 mg weekly, with the dosage increasing to 15 mg weekly after 4 weeks, in combination with folic acid (1 mg daily). Good responders were defined as patients who had a DAS28 of ≤2.4 at 6 months (patients with remission of disease symptoms). Poor responders were defined as patients who had a DAS28 of >2.4. In this study, we analyzed the association between clinical parameters such as sex of patients, age of patients, age at disease onset, disease duration, rheumatoid factor, anti-CCP antibodies, ESR values, presence of joints erosions, presence of extra-articular manifestations and the response to MTX in RA patients. Multivariate logistic regression analysis showed four independent factors significantly associated with good response to MTX treatment: older age at disease onset, low ESR, no erosive disease and negative RF. The results of our study suggest that a younger age at disease onset, the presence of RF, erosive disease, as well as a high level of ESR are associated with worse response to MTX therapy.

Sex- and gender-related differences in psoriatic arthritis

Psoriatic arthritis (PsA) is an inflammatory musculoskeletal disease with a chronic, progressive course. Various aspects of PsA, including its clinical features, disease course and response to treatment, are influenced by sociodemographic characteristics of the patient. This includes patient sex, the biological attributes associated with being male or female, and gender, a sociocultural construct that comprises attitudes, traits and behaviours associated with being a man or a woman. An understanding of sex- and gender-related differences in PsA, as well as their underlying mechanisms, is therefore important for individualized care. In this narrative review, the influence of sex and gender on PsA manifestation and course, patient function and quality of life, and their association with comorbidities are described. Sex- and gender-related disparities in response to advanced therapies and their potential underlying mechanisms are delineated. Differences in pathophysiological mechanisms between male and female patients including genetics, immune and hormonal mechanisms are discussed. Finally, fertility and pregnancy outcomes in PsA are outlined. By adopting sex and gender lenses, this review is aimed at highlighting key differences between male and female patients with PsA and uncovering mechanisms underlying these differences, ultimately promoting individualized care of men and women with PsA and informing future research in this area.

Impact of continuity of care on risk for major osteoporotic fracture in patients with new onset rheumatoid arthritis

There is a clear relationship between rheumatoid arthritis (RA) and major osteoporotic fracture (MOF), although there is limited evidence on the effect of continuity of care (COC) on MOF in these patients. We investigated the association between COC and risk of MOF, including fractures of the lumbar spine and pelvis, forearm, and hip, among newly diagnosed RA patients aged ≥ 60 years. A total of 8715 incident RA patients from 2004 to 2010 were included from the Korean National Health Insurance Service-Senior cohort database. Participants were categorized into a good and bad COC group according to the COC index. The cumulative incidence of MOF was higher in RA patients with bad than in those with good COC (p < 0.001). The incidence rates of MOF were 4439 and 3275 cases per 100,000 person-years in patients with bad and good COC, respectively. RA patients with bad COC had an increased incidence of overall MOF (adjusted hazard ratio, 1.32; 95% confidence interval, 1.14–1.53), with the highest increase in risk being that of forearm fracture. An increased MOF risk in patients with bad COC was predominantly observed in females. This study suggested that interventions that can improve COC in patients with RA should be considered.

Identification of poor prognostic joint locations in an early rheumatoid arthritis cohort at risk of rapidly progressing disease: a post-hoc analysis of the Phase III AGREE study

Background

Rheumatoid arthritis (RA) is a heterogeneous disease with established poor prognostic factors such as seropositivity, joint damage, and high disease activity at an early, treatment-naïve stage of disease. However, few studies have examined if specific joint locations are correlated with these factors in such a population. This analysis explored the potential correlation of individual swollen and erosive joints with other disease characteristics at baseline and with remission rates in a post-hoc analysis of the Phase III randomized AGREE study.

Methods

Methotrexate (MTX)-naïve, erosive, RF- and/or ACPA-positive early RA patients (N = 509) were retrospectively evaluated. Baseline joint swelling was analyzed for large and small joints. Baseline erosions were analyzed for wrist, MCP1–5, IP1, PIP2–5 and MTP1–5. Remission rates were assessed after 6 months of treatment with abatacept (ABA) + MTX (N = 256) or MTX (N = 253). The following statistical tests were used: Chi-Square or Fisher’s exact test (categorical variables); Student’s t-test or Wilcoxon rank-sum test (continuous variables); continuity-corrected Chi-square test (efficacy remission endpoints).

Results

Baseline swelling was most frequent in wrist (91.9%) and MCP2 joint (89.1%), while baseline erosion was most frequent in MTP5 joint (43.5%). Swollen shoulder was significantly correlated (p < 0.0001) with swelling of almost all other large or medium joints. Baseline swelling in the knee, temporomandibular joint (TMJ), wrist and elbow was highly correlated (p < 0.001) with higher tender and swollen joint counts, higher DAS28(CRP) and higher SDAI and CDAI. Baseline swelling was not correlated with erosion per joint, except for MCP2. The largest difference in mean Boolean remission rates at 6 months was in patients with baseline swollen wrist favoring ABA + MTX (14.0% vs 4.4%; p < 0.001).

Conclusions

Swelling in the large and medium joints (knee, TMJ, elbow and wrist) was highly correlated with severe disease activity while MCP2 swelling seemed to be correlated with joint damage. The correlation of joint locations at an early, treatment-naïve stage with poor prognostic factors, higher disease activity and joint damage, could establish a rapidly progressing anatomical pattern in early RA.

Trial registration: ClinicalTrials.gov NCT00122382, registered July 2005.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00252-4.

Gender influence on clinical manifestations, depressive symptoms and brain-derived neurotrophic factor (BDNF) serum levels in patients affected by fibromyalgia

INTRODUCTION

OBJECTIVES: Fibromyalgia (FM) is a common rheumatic disorder characterized by chronic, widespread pain associated with several not painful symptoms. The contribution of gender to the manifestation of the disease may influence the higher prevalence of FM among women. In spite of this, how patients' gender influences the clinical manifestation of FM is still not well understood. The frequent association with neuropsychiatric symptoms raised the attention on the role of neurotrophins, including the brain-derived neurotrophic factor (BDNF) as potential biomarkers of the condition. Aims of the study were to evaluate the influence of gender on clinical manifestations and to investigate BDNF serum levels as a potential biomarker of FM.

METHODS

We consecutively enrolled 201 adult patients of both sexes diagnosed with FM. For each patient, we collected clinical and clinimetric data and, in a subgroup of 40 patients, we measured serum BDNF levels. BDNF levels have been measured also in 40 matched healthy controls (HC).

RESULTS

Several symptoms were significantly higher in women compared with men, including pain, fatigue, memory problems, tenderness, balance problems and sensitivity to environmental stimuli. On the contrary, men reported a significant higher frequency of coexisting depressive symptoms. BDNF levels were significantly lower in FM patients compared with HC, discriminating with good accuracy the condition.

CONCLUSION

Gender influences FM clinical manifestations, with a higher prevalence of pain, fatigue and other common FM symptoms among women while higher frequency of neuropsychiatric symptoms among men. BDNF offers promises as a potential biomarker of the disease. Key Points • Gender-related differences in the clinical manifestations of FM may contribute to the higher prevalence of FM among females. Indeed, women show higher levels of pain and symptoms traditionally associated to FM, which are evaluated to establish the diagnosis according to the clinical criteria. • The new insights into the pathogenesis of the disease raised the attention on the role of brain mediators in FM. Among these, BNDF shows potential as a diagnostic biomarker.

Leveraging Antibody, B Cell and Fc Receptor Interactions to Understand Heterogeneous Immune Responses in Tuberculosis

Despite over a century of research, Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), continues to kill 1.5 million people annually. Though less than 10% of infected individuals develop active disease, the specific host immune responses that lead to Mtb transmission and death, as well as those that are protective, are not yet fully defined. Recent immune correlative studies demonstrate that the spectrum of infection and disease is more heterogenous than has been classically defined. Moreover, emerging translational and animal model data attribute a diverse immune repertoire to TB outcomes. Thus, protective and detrimental immune responses to Mtb likely encompass a framework that is broader than T helper type 1 (Th1) immunity. Antibodies, Fc receptor interactions and B cells are underexplored host responses to Mtb. Poised at the interface of initial bacterial host interactions and in granulomatous lesions, antibodies and Fc receptors expressed on macrophages, neutrophils, dendritic cells, natural killer cells, T and B cells have the potential to influence local and systemic adaptive immune responses. Broadening the paradigm of protective immunity will offer new paths to improve diagnostics and vaccines to reduce the morbidity and mortality of TB.

Immune Sexual Dimorphism: Connecting the Dots

Despite numerous studies of immune sexual dimorphism, sexual differences are not rigorously mapped and dimorphic mechanisms are incompletely understood. Current immune research typically studies sex differences in specific cells, tissues, or diseases but without providing an integrated picture. To connect the dots, we suggest comprehensive research approaches to better our understanding of immune sexual dimorphism and its mechanisms.

Application of Induced Pluripotent Stem Cells for Disease Modeling and 3D Model Construction: Focus on Osteoarthritis

Since their discovery in 2006, induced pluripotent stem cells (iPSCs) have shown promising potential, specifically because of their accessibility and plasticity. Hence, the clinical applicability of iPSCs was investigated in various fields of research. However, only a few iPSC studies pertaining to osteoarthritis (OA) have been performed so far, despite the high prevalence rate of degenerative joint disease. In this review, we discuss some of the most recent applications of iPSCs in disease modeling and the construction of 3D models in various fields, specifically focusing on osteoarthritis and OA-related conditions. Notably, we comprehensively reviewed the successful results of iPSC-derived disease models in recapitulating OA phenotypes for both OA and early-onset OA to encompass their broad etiology. Moreover, the latest publications with protocols that have used iPSCs to construct 3D models in recapitulating various conditions, particularly the OA environment, were further discussed. With the overall optimistic results seen in both fields, iPSCs are expected to be more widely used for OA disease modeling and 3D model construction, which could further expand OA drug screening, risk assessment, and therapeutic capabilities.

Contribution of Dysregulated DNA Methylation to Autoimmunity

Epigenetic mechanisms, such as DNA methylation, histone modifications, and non-coding RNAs are known regulators of gene expression and genomic stability in cell growth, development, and differentiation. Because epigenetic mechanisms can regulate several immune system elements, epigenetic alterations have been found in several autoimmune diseases. The purpose of this review is to discuss the epigenetic modifications, mainly DNA methylation, involved in autoimmune diseases in which T cells play a significant role. For example, Rheumatoid Arthritis and Systemic Lupus Erythematosus display differential gene methylation, mostly hypomethylated 5′-C-phosphate-G-3′ (CpG) sites that may associate with disease activity. However, a clear association between DNA methylation, gene expression, and disease pathogenesis must be demonstrated. A better understanding of the impact of epigenetic modifications on the onset of autoimmunity will contribute to the design of novel therapeutic approaches for these diseases.

Effective factors on Sharp Score in patients with rheumatoid arthritis: a retrospective study

Background

This study aims to describe the association between sharp score and clinical indexes, bone metabolism indexes, Disease Activity Score (DAS28) and sociodemographic factors in rheumatoid arthritis (RA).

Methods

Data were collected from the HIS (hospital information system), a national inpatient database in China, with information on the patients hospitalized during the period from 2012 to 2019. The association between sharp score and effective factors were identified using multinomial logistic regression and association rule mining (ARM).

Results

Three thousand eight hundred and forty patients were included: 82.66% males, 17.34% females, mean (SD) age 56.95 (12.68) years and symptom duration 3.45 (1.09) years. Spearman correlation analysis and Association rules analysis showed that there were significant positive correlations between sharp score and effective factors. Logistic regression analysis presented that erythrocyte sedimentation rate (ESR), high-sensitivity C-reactive protein (CRP), rheumatoid factor (RF) were risk factors of sharp score. In the analysis of individual outcomes, sex, age, symptom duration, DSA28 score, RF, ever drinker, and radiographic grading of hands were influence factors of sharp score.

Conclusion

Sharp score should be taken into consideration in formulating treatment strategies in RA.

Disease activity and its predictors in early inflammatory arthritis: findings from a national cohort

OBJECTIVES

We set out to characterize patient factors that predict disease activity during the first year of treatment for early inflammatory arthritis (EIA).

METHODS

We used an observational cohort study design, extracting data from a national clinical audit. All NHS organizations providing secondary rheumatology care in England and Wales were eligible to take part, with recruitment from 215/218 (99%) clinical commissioning groups (CCGs)/Health Boards. Participants were >16 years old and newly diagnosed with RA pattern EIA between May 2018 and May 2019. Demographic details collected at baseline included age, gender, ethnicity, work status and postcode, which was converted to an area level measure of socioeconomic position (SEP). Disease activity scores (DAS28) were collected at baseline, three and 12 months follow-up.

RESULTS

A total of 7455 participants were included in analyses. Significant levels of CCG/Health board variation could not be robustly identified from mixed effects modelling. Gender and SEP were predictors of low disease activity at baseline, three and 12 months follow-up. Mapping of margins identified a gradient for SEP, whereby those with higher degrees of deprivation had higher disease activity. Black, Asian and Minority Ethnic patients had lower odds of remission at three months follow-up.

CONCLUSION

Patient factors (gender, SEP, ethnicity) predict disease activity. The rheumatology community should galvanise to improve access to services for all members of society. More data are required to characterize area level variation in disease activity.

Plasma expression of microRNA-425-5p and microRNA-451a as biomarkers of cardiovascular disease in rheumatoid arthritis patients

To validate in a cohort of 214 rheumatoid arthritis patients a panel of 10 plasmatic microRNAs, which we previously identified and that can facilitate earlier diagnosis of cardiovascular disease in rheumatoid arthritis patients. We identified 10 plasma miRs that were downregulated in male rheumatoid arthritis patients and in patients with acute myocardial infarction compared to controls suggesting that these microRNAs could be epigenetic biomarkers for cardiovascular disease in rheumatoid arthritis patients. Six of those microRNAs were validated in independent plasma samples from 214 rheumatoid arthritis patients and levels of expression were associated with surrogate markers of cardiovascular disease (carotid intima-media thickness, plaque formation, pulse wave velocity and distensibility) and with prior cardiovascular disease. Multivariate analyses adjusted for traditional confounders and treatments showed that decreased expression of microRNA-425-5p in men and decreased expression of microRNA-451 in women were significantly associated with increased (β = 0.072; p = 0.017) and decreased carotid intima-media thickness (β = −0.05; p = 0.013), respectively. MicroRNA-425-5p and microRNA-451 also increased the accuracy to discriminate patients with pathological carotid intima-media thickness by 1.8% (p = 0.036) in men and 3.5% (p = 0.027) in women, respectively. In addition, microRNA-425-5p increased the accuracy to discriminate male patients with prior cardiovascular disease by 3% (p = 0.008). Additionally, decreased expression of microRNA-451 was significantly associated with decreased pulse wave velocity (β = −0.72; p = 0.035) in overall rheumatoid arthritis population. Distensibility showed no significant association with expression levels of the microRNAs studied. We provide evidence of a possible role of microRNA-425-5p and microRNA-451 as useful epigenetic biomarkers to assess cardiovascular disease risk in patients with rheumatoid arthritis.

Increased Expression of Extracellular Vesicles Is Associated With the Procoagulant State in Patients With Established Rheumatoid Arthritis

This study sought to identify different subpopulations of extracellular vesicles (EVs) in plasma from female patients with established rheumatoid arthritis (RA) in relation to the activation of coagulation and fibrin formation in these patients. Forty women were included in the study, 20 patients and 20 age-matched healthy controls. The mean disease duration in patients was 13.0 (5.0-25.0) years, with medium to high disease activity despite ongoing treatment with low-dose prednisolone and methotrexate. There were no differences between the investigated groups regarding the presence of traditional cardiovascular risk factors. The concentration of phosphatidylserine-positive (PS+) EVs; platelet (CD42a+), leucocyte (CD45+), monocyte (CD14+), and endothelial (CD144+)-derived EVs; and EVs-expressing tissue factor (CD142+), P-selectin (CD62P+), and E-selectin (CD62E+) were determined by flow cytometry analysis. Overall hemostasis potential (OHP) was assessed to follow the hemostatic disturbances, including the parameters for overall coagulation potential (OCP) and overall fibrinolytic potential (OFP). Fibrin clot turbidity was measured together with clot lysis time, and scanning electron microscopy was performed. Increased concentrations of PS+, CD42a+, CD142+, CD45+, CD14+, and CD62P+ EVs were found in plasma from patients with RA compared to healthy controls, and the concentrations of PS+, CD42a+, CD14+, and CD62P+ EVs were positively correlated with the inflammatory parameters in RA patients. Positive correlations were also found between the levels of PS+ and CD42a+ EVs and OCP as well as between the levels of PS+, CD42a+, and CD62P+EVs and OHP. The levels of PS+, CD42a+, CD14+, CD62P+, and CD62E+ EVs were negatively correlated with OFP. Elevated levels of circulating EVs of different cell origins were found in patients with established RA, in relation to the inflammatory burden and coagulation activation in the disease.

Decrease in handgrip strength in rheumatoid arthritis (RA): is there a sex-related difference?

Rheumatoid arthritis occurs two to three times more often in women than in men and it has been less studied in men. The results of gender influence on clinical course of the disease are contradictory. The aim of this study is to determine the difference in handgrip strength between female and male RA patients in comparison to healthy individuals. The study included 100 RA patients and 100 healthy individuals (50% were male in both groups). Handgrip strength was measured in both hands using a dynamometer. A two-way ANCOVA was used to analyse the data and age was included in the study as covariate. The results show that both male and female RA patients have lower handgrip strength compared to healthy individuals. The analysis of gender and disease interaction has shown that male RA patients have lower handgrip strength than female RA patients in comparison with the healthy group, age adjusted. This interaction is evident and statistically significant in both right hand (F 1, 195) = 14.62; p < 0.01) and left hand (F 1, 195) = 20.54; p < 0.01). The common-language effect size has shown that there is 92% (right hand) and 93% (left hand) chance that male individual will have stronger handgrip than his female counterpart. In RA patients, there is 77% chance for both hands that male will have stronger handgrip. Men and women with RA have significantly lower handgrip strength compared to healthy individuals and the difference is more pronounced in men which was not previously observed in the literature.

Sex disparities in the prevalence of physical function disabilities: a population-based study in a low-income community

BACKGROUND

Functional disability continues to be a significant public health problem that increases older adults' vulnerability to experience a diminished quality of life, loss of independence, higher healthcare costs and health services utilization, and increased risks of mortality. Thus, we aimed to study the prevalence of functional disabilities by sex according to the types of daily living activities, controlling for specific sociodemographic variables among older Hispanics from low-income communities.

METHODS

We used a cross-sectional epidemiological research design, considering a complex sampling design of households to interview adults ≥65 years living in low-income communities in Puerto Rico. Functional disability was measured by the PROMIS® Physical Function Short Form-20 T-score. The selected community was reported to have 5980 adult residents ≥65 years, according to the USA Census. The prevalence of functional disability was estimated using the logistic regression model, weighting by the effect of the sampling. Our estimated prevalence was compared between sexes using the prevalence ratio (PR), which was estimated with logistic regression models, controlling for age, income, number of chronic conditions, high and low impact of chronic conditions in functional disabilities, marital status, and sampling design.

RESULTS

We recruited 211 older Hispanics from a randomly selected sample. Their mean age was 74.4 ± 7.1 years, with female predominance (57.3%). The overall estimated prevalence of physical function disability using T-score among females was 2.70 (95% CI: 1.4, 5.1) times the estimated prevalence of physical function disability among males. Women were more likely to report functional disabilities in instrumental activities of daily living, self-care activities, and functional mobility compared to males. However, sex differences were largely explained by the presence of musculoskeletal conditions of high impact in functional disability.

CONCLUSIONS

The females in our study bear the greater burden of physical function disability in their adult age. Health policies, as well as future studies, should be targeted at reducing the burden of physical function disabilities in different types of daily activities through gender-sensitive disability self-management programs.

Lack of association between CYB5A gene rs1790834 polymorphism and the response to leflunomide in women with rheumatoid arthritis

Aim

Leflunomide is a disease-modifying antirheumatic drug used in therapy for rheumatoid arthritis (RA). Previous studies indicated that oestrogens and androgens may affect the response to leflunomide in RA patients. The synthesis of androgens is regulated by cytochrome CYB5A. The aim of this study was to examine the association between the CYB5A gene rs1790834 polymorphism and the response to leflunomide in women with RA.

Methods

The study included 111 women diagnosed with RA. Leflunomide was administered in monotherapy at a dose of 20 mg/day. All patients underwent a monthly evaluation for 12 months after the initiation of treatment with leflunomide.

Results

After 12 months of therapy, the changes in individual disease activity parameters, such as: DAS28, ESR, CRP and VAS, were not statistically significantly different between rs1790834 genotypes in the Kruskal–Wallis test.

Conclusions

The results of our study suggest lack of statistically significant association between the CYB5A gene rs1790834 polymorphism and the response to leflunomide in women with RA.

Predictors of unacceptable pain with and without low inflammation over 5 years in early rheumatoid arthritis-an inception cohort study

Objectives

Pain is a major symptom in patients with rheumatoid arthritis (RA). In early RA, pain is usually due to synovitis, but can also persist despite effective anti-inflammatory treatment. The objective of this study was to investigate the pain course over time and predictors of unacceptable pain and unacceptable pain with low inflammation, in patients with early RA.

Methods

An inception cohort of 232 patients with early RA, recruited in 1995–2005, was followed in a structured programme for 5 years. Pain was assessed using a visual analogue scale (VAS; 0–100). Unacceptable pain was defined as VAS pain > 40 based on the patient acceptable symptom state (PASS) and low inflammation as CRP < 10 mg/l. Baseline predictors of unacceptable pain were evaluated using logistic regression analysis.

Results

Pain improved significantly during the first 6 months, but then remained basically unchanged. Thirty-four per cent of the patients had unacceptable pain 5 years after inclusion. Baseline predictors of unacceptable pain after 5 years were lower swollen joint counts [odds ratio (OR) 0.71 per standard deviation (95% confidence interval (CI) 0.51–0.99)] and higher VAS for pain and global assessment of disease activity. Unacceptable pain with low inflammation after 5 years was negatively associated with anti-CCP antibodies [OR 0.50 (95% CI 0.22–0.98)].

Conclusion

Over one third of the patients had unacceptable pain 5 years after inclusion. Lower swollen joint count was associated with unacceptable pain at 5 years. The results may be explained by the positive effects of treatment on pain related to inflammation. Non-inflammatory long-lasting pain appears to be a greater problem in anti-CCP-negative patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02550-7.

Sex-Specific Association of Left Ventricular Hypertrophy With Rheumatoid Arthritis

Objectives: Clinical expression of rheumatoid arthritis (RA) varies by gender, but whether cardiovascular disease (CVD) is gender related in RA is unknown. Left ventricular (LV) hypertrophy (LVH) is a hallmark of CVD in RA patients. We investigated whether the association of LVH with RA is gender driven.

Methods: Consecutive outpatients with established RA underwent echocardiography with measurement of LVH at baseline and one follow-up. All participants had no prior history of CVD or diabetes mellitus. We assessed CVD risk factors associated with LVH at follow-up, including sex, age, arterial blood pressure, and body mass index (BMI). We also evaluated inflammatory markers, autoimmunity, disease activity, and the use of RA medications as predictors of LVH.

Results: We recruited 145 RA patients (121 females, 83%) and reassessed them after a median (interquartile range) of 36 months (24–50). At baseline, women were more dyslipidemic but otherwise had fewer CVD risk factors than men, including less prevalent smoking habit and hypertension, and smaller waist circumference. At follow-up, we detected LVH in 42/145 (44%) RA patients. LV mass significantly increased only in women. In multiple Cox regression analysis, women with RA had the strongest association with LVH, independently from the presence of CVD risk factors (OR, 6.56; 95% CI, 1.34–30.96) or RA-specific characteristics (OR, 5.14; 95% CI, 1.24–21.34). BMI was also significantly and independently associated with LVH.

Conclusion: Among established RA patients, women carry the highest predisposition for LVH.

Association of interleukin-17A rs2275913 polymorphism with rheumatoid arthritis susceptibility in Sudanese population

Objectives:

Rheumatoid arthritis is a chronic inflammatory autoimmune disease. This study aimed to determine the association of interleukin-17A-197G/A polymorphism with rheumatoid arthritis in Sudanese patients.

Methods:

A case–control study was conducted between March and December 2018. Clinical and demographic data of the study participants were collected and analyzed. Polymerase chain reaction restriction fragment length polymorphism molecular technique was done to investigate interleukin-17A-197G/A polymorphisms. All statistical tests were considered statistically significant when p < 0.05.

Results:

The study population included 266 participants aged between 1 and 85 years, with an average of 40 years, classified into 85 (31.2%) cases (mean age 48.5 ± 11.3 years), and 181 (68.8%) controls (mean age 35.3 ± 15.9 years). The interleukin-17A homozygote AA genotype was more frequent among the control group compared to the case group; 95 (52.5%) and 7 (8.2%), respectively. The homozygote GG and the heterozygote AG genotypes were proportionally not different among the cases and control groups; 13 (54.2%) and 11 (45.8%), and 65 (46.4%) and 75 (53.6%), respectively. According to the distribution of interleukin-17A genotypes, a statistically significant difference was observed among cases with the interleukin-17A AA and AG genotypes, p values 0.001 and 0.004, respectively. For the association interleukin-17A genotypes and family history a negatively significant association was reported (95% confidence interval, –0.219, p value = 0.001). There was also a negatively significant association of interleukin-17A genotypes and anti-cyclic citrullinated peptide (95% confidence interval, −0.141, p value = 0.002).

Conclusion:

This study is the first study in Sudan established the association between interleukin-17A-197G/A (rs2275913) polymorphisms and susceptibly to rheumatoid arthritis. These findings appeal for further research in Sudan to investigate the exact role of IL-17A in immunopathology and disease severity among Sudanese rheumatoid arthritis

Cannabinoid-based therapy as a future for joint degeneration. Focus on the role of CB2 receptor in the arthritis progression and pain: an updated review

Over the last several decades, the percentage of patients suffering from different forms of arthritis has increased due to the ageing population and the increasing risk of civilization diseases, e.g. obesity, which contributes to arthritis development. Osteoarthritis and rheumatoid arthritis are estimated to affect 50-60% of people over 65 years old and cause serious health and economic problems. Currently, therapeutic strategies are limited and focus mainly on pain attenuation and maintaining joint functionality. First-line therapies are nonsteroidal anti-inflammatory drugs; in more advanced stages, stronger analgesics, such as opioids, are required, and in the most severe cases, joint arthroplasty is the only option to ensure joint mobility. Cannabinoids, both endocannabinoids and synthetic cannabinoid receptor (CB) agonists, are novel therapeutic options for the treatment of arthritis-associated pain. CB₁ receptors are mainly located in the nervous system; thus, CB₁ agonists induce many side effects, which limit their therapeutic efficacy. On the other hand, CB₂ receptors are mainly located in the periphery on immune cells, and CB₂ modulators exert analgesic and anti-inflammatory effects in vitro and in vivo. In the current review, novel research on the cannabinoid-mediated analgesic effect on arthritis is presented, with particular emphasis on the role of the CB₂ receptor in arthritis-related pain and the suppression of inflammation.

Influence of Age and Sex on Disease Course and Treatment in Rheumatoid Arthritis

Objective

More than 50% of patients with rheumatoid arthritis (RA) are >65 years at diagnosis. Age of onset and sex may influence the disease course, outcome and treatment. This study follows a large cohort of patients with early RA to assess contributions of age and sex to disease outcomes.

Methods

Patients from the BARFOT cohort, n=2837 (68% women), were followed for eight years at predefined time points to assess inflammation, function, joint destruction and treatment with disease modifying anti-rheumatic drugs (DMARDs) and glucocorticoids (GC). The patients were divided by sex and age at inclusion (<40, 40–54, 55–69 and ≥70 years).

Results

For both sexes, disease activity, function and pain improved over time, significantly more in men than in women in all age groups. In men, those <40 years displayed significantly lower DAS28 compared with all other groups. This group was also the least represented group in the study. The Sharp van der Heijde Score (SHS) increased over time in both sexes and all age groups. Women ≥70 years showed less improvement in disability and the highest progression of SHS mainly due to increased joint space narrowing. Patients <40 years were more likely to receive biological DMARDs, while those ≥70 years more often received only GC treatment.

Conclusion

There were significant age- and sex-dependent differences in the medical treatment and in outcome of RA 8 years after diagnosis. The differences were most pronounced in men<40 and women ≥70 years, but whether they are due to disease phenotype or treatment is unclear.

Dairy Consumption: Does It Make an Impact on Self-Reported Disease Activity of Inflammatory Arthritis?

Background

As researchers and the public become more cognizant of the impacts of diet and nutrition on health, continued research is needed to provide evidence to support dietary claims. At present, there exists mixed reporting on the effects of dairy consumption and disease activity of inflammatory arthritis (IA).

Objective

This study attempts to advance current research on the relationship between dairy consumption and self-reported disease activity in patients with IA and to investigate whether dietary modifications can be helpful as a conservative, cost-effective, and accessible supplement to established treatments.

Methods

Participants completed a modified diet history questionnaire (DHQ), which assessed dairy consumption over the past year, and a Routine Assessment of Patient Index Data 3 (RAPID3) questionnaire, which assessed a participants’ self-reported inflammatory disease activity. DHQ and RAPID3 were analyzed using a Pearson product-moment partial correlation to assess variables’ relationships. Participants completed the questionnaire in the setting of a rheumatology clinic. Two hundred and four participants were recruited for this study. All of the participants were at least 18 years of age, capable of giving informed consent, and were formally diagnosed with either rheumatoid arthritis or psoriatic arthritis by a board-certified rheumatologist. 

Results

The results from the questionnaires found that dairy consumption does not contribute to self-reported IA disease activity. While 11 of the 16 DHQ variables maintained a positive correlation with the overall RAPID3 scores, none of these possessed statistical significance. Only when controlling for age and sex did the study find two statistically significant variable correlations between the quantity of milk consumed as a beverage (r=0.147, n=193, p=0.043) and milk added to cereal (r=0.170, n=189, p=0.019) with the RAPID3 scores.

Conclusion

In summation, the study found no notable correlation between dairy consumption and patients’ self-reported IA disease activity.

Multiple intravenous tranexamic acid doses in total knee arthroplasty in patients with rheumatoid arthritis: a randomized controlled study

Background

We aimed to determine the efficacy and safety of multiple doses of intravenous tranexamic acid (IV-TXA) on perioperative blood loss in patients with rheumatoid arthritis (RA) who had undergone primary unilateral total knee arthroplasty (TKA).

Methods

For this single-center, single-blind randomized controlled clinical trial, 10 male and 87 female participants with RA, aged 50–75 years, who underwent unilateral primary TKA were recruited. The patients received one dose of 1 g IV-TXA 10 min before skin incision, followed by articular injection of 1.5 g tranexamic acid after cavity suture during the surgery. The patients were randomly assigned (1:1) into two groups and received an additional single dose of IV-TXA (1 g) for 3 h (group A) or three doses of IV-TXA (1 g) for 3, 6, and 12 h (group B) postoperatively. Primary outcomes were total blood loss (TBL), hidden blood loss (HBL), and maximum hemoglobin (Hb) level decrease. Secondary outcomes were transfusion rate and D-dimer levels. All parameters were measured postoperatively during inpatient hospital stay.

Results

The mean TBL, HBL, and maximum Hb level decrease in group B (506.1 ± 227.0 mL, 471.6 ± 224.0 mL, and 17.5 ± 7.7 g/L, respectively) were significantly lower than those in group A (608.8 ± 244.8 mL, P = 0.035; 574.0 ± 242.3 mL, P = 0.033; and 23.42 ± 9.2 g/L, P = 0.001, respectively). No episode of transfusion occurred. The D-dimer level was lower in group B than in group A on postoperative day 1 (P <  0.001), and the incidence of thromboembolic events was similar between the groups (P > 0.05).

Conclusion

In patients with RA, three doses of postoperative IV-TXA further facilitated HBL and Hb level decrease without increasing the incidence of adverse events in a short period after TKA.

Trial registration

The trial was registered in the Chinese Clinical Trial Registry (ChiCTR1900025013).

Glucocorticoid use is associated with an increased risk of hypertension

OBJECTIVES

Patients with RA are frequently treated with glucocorticoids (GCs), but evidence is conflicting about whether GCs are associated with hypertension. The aim of this study was to determine whether GCs are associated with incident hypertension in patients with RA.

METHODS

A retrospective cohort of patients with incident RA and without hypertension was identified from UK primary care electronic medical records (Clinical Practice Research Datalink). GC prescriptions were used to determine time-varying GC use, dose and cumulative dose, with a 3 month attribution window. Hypertension was identified through either: blood pressure measurements >140/90 mmHg, or antihypertensive prescriptions and a Read code for hypertension. Unadjusted and adjusted Cox proportional hazards regression models were fitted to determine whether there was an association between GC use and incident hypertension.

RESULTS

There were 17 760 patients in the cohort. A total of 7421 (42%) were prescribed GCs during follow-up. The incident rate of hypertension was 64.1 per 1000 person years (95% CI: 62.5, 65.7). The Cox proportional hazards model indicated that recent GC use was associated with a 17% increased hazard of hypertension (hazard ratio 1.17; 95% CI: 1.10, 1.24). When categorized by dose, only doses above 7.5 mg were significantly associated with hypertension. Cumulative dose did not indicate a clear pattern.

CONCLUSION

Recent GC use was associated with incident hypertension in patients with RA, in particular doses ≥7.5 mg were associated with hypertension. Clinicians need to consider cardiovascular risk when prescribing GCs, and ensure blood pressure is regularly monitored and treated where necessary.

Symmetry Criterion for Patients with Rheumatoid Arthritis of the Foot: A Cross-Sectional Study

Objective: The aim of the study was to analyze the feet of rheumatoid arthritis (RA) patients, to determine the degree to which both feet were affected, primarily analyzing the severity of RA in both feet looking at structure and morphology, and secondly looking at the symmetry in terms of the anthropometrics and posture. Method: This cross-sectional study was conducted from January to December 2018. The data from 229 patients with RA and with foot pain and no RA recruited (Granada, Spain) were analyzed. Two researchers independently interviewed the patients to obtain the study data. The clinical data were obtained using specific foot health and quality of life questionnaires and a validated platform for foot measurement. Anthropometric measurements were obtained by means of a foot measurement platform and the Foot Posture Index (FPI). The bivariate analysis was performed with the Student’s t test and the non-parametric Wilcoxon test. The level of significance was established at p < 0.05. Results: In the RA group, anthropometric measurements revealed significant differences between the left and right feet in 13 of the 23 parameters considered, as follows: (non-load-bearing) foot length, length of the first metatarsophalangeal joint, maximum height of the internal longitudinal arch, and width of the midfoot (p < 0.001, p = 0.038, p < 0.001, and p = 0.037 respectively); and Foot Posture Index (p = 0.001). Conclusions: In patients with RA, statistically significant differences were found in the Foot Posture Index and in several parameters related to foot structure and morphology. From this, we conclude that from a morphological, structural, and postural standpoint, a pattern of symmetric joint involvement should not be viewed as a specific criterion for RA in the foot.

Pain in Women: A Perspective Review on a Relevant Clinical Issue that Deserves Prioritization

Introduction

Gender equity and gender medicine are opportunities not to be missed, and this Expert Group Opinion Paper on pain in women aims to review the treatment of pain conditions mainly affecting women, as well as the fundamental aspects of the different clinical response to drug treatment between the genders, and what can be done for gender-specific rehabilitation.

Methods

Perspective review.

Results

Genotypic and phenotypic differences in pain between the sexes are conditioned by anatomical, physiological, neural, hormonal, psychological, social, and cultural factors, such as the response to pharmacological treatment to control pain. The examination of these factors shows that women are affected by pain diseases more frequently and severely than men and that they report pain more frequently and with a lower pain threshold than men. Some forms of pain are inherently related to gender differences, such as pain related to the genitourinary system. However, other forms of chronic pain are seen more frequently in women than men, such as migraine, rheumatological, and musculoskeletal pain, in particular fibromyalgia.

Discussion

Research is needed into the pathophysiological basis for gender differences in the generation of acute pain and maintenance of chronic pain, including the factors that put women at higher risk for developing chronic pain. In addition, different specialties need to collaborate to develop gender-related diagnostic and therapeutic guidelines, and healthcare professionals need to upskill themselves in the appropriate management of pain using existing diagnostic tools and therapeutic options.

Multi-Modal Characterization of Monocytes in Idiopathic Pulmonary Fibrosis Reveals a Primed Type I Interferon Immune Phenotype

Idiopathic pulmonary fibrosis (IPF) is the most severe form of chronic lung fibrosis. Circulating monocytes have been implicated in immune pathology in IPF but their phenotype is unknown. In this work, we determined the immune phenotype of monocytes in IPF using multi-colour flow cytometry, RNA sequencing and corresponding serum factors, and mapped the main findings to amount of lung fibrosis and single cell transcriptomic landscape of myeloid cells in IPF lungs. We show that monocytes from IPF patients displayed increased expression of CD64 (FcγR1) which correlated with amount of lung fibrosis, and an amplified type I IFN response ex vivo. These were accompanied by markedly raised CSF-1 levels, IL-6, and CCL-2 in serum of IPF patients. Interrogation of single cell transcriptomic data from human IPF lungs revealed increased proportion of CD64hi monocytes and "transitional macrophages" with higher expression of CCL-2 and type I IFN genes. Our study shows that monocytes in IPF patients are phenotypically distinct from age-matched controls, with a primed type I IFN pathway that may contribute to driving chronic inflammation and fibrosis. These findings strengthen the potential role of monocytes in the pathogenesis of IPF.

The role of vitamin D in autoimmune diseases: could sex make the difference?

Over the last decades, a central role for vitamin D in immune modulation has been well established. The active form of vitamin D, i.e., 1,25-dihydroxyvitamin D, through the interaction with vitamin D receptor, exerts different activities on the innate and adaptive immune system, among which suppression of inflammation and promotion of tolerogenic responses. Vitamin D insufficiency has been linked to autoimmune disorders that commonly display significant differences between females and males due to genetic, epigenetic, hormonal, and environmental factors. Notably, a number of studies recently showed a cross-talk between vitamin D and the sex hormone estrogen. Estrogen-mediated effects on immune response may favor a Th1 profile or a Th2 profile, depending on hormone concentration. Thus, estrogen-mediated effects appear to be variable on autoimmunity depending on its concentration but also on the pathogenic mechanisms underlying the different autoimmune diseases (i.e., Th1- or Th2-mediated diseases). Notably, estrogen has been demonstrated to enhance vitamin D function favoring its accumulation, and increasing the expression of vitamin D receptor, thus resulting in a more potent anti-inflammatory response in females than males. On the other hand, vitamin D has been shown to downregulate in immune cells the expression of aromatase, which converts testosterone to estrogen, leading to a decrease in estrogen level. Overall, available data allow us to hypothesize a higher protective effect of vitamin D-based therapeutic approaches in women, at least in fertile age, than in men. Future studies are needed to expand current knowledge on the immunomodulatory role of vitamin D in a sex and gender perspective, paving the way to a more personalized therapeutic approach in autoimmune diseases.

The Influence of Menopause and Inflammation on Redox Status and Bone Mineral Density in Patients with Rheumatoid Arthritis

Although oxidative stress is considered to be one of the key pathogenic factors in rheumatoid arthritis (RA), there is insufficient knowledge regarding the impact of menopause on redox status in this population. Thus, this study is aimed at assessing the influence of menopause within healthy women and within RA patients as well as the impact of RA in premenopausal and postmenopausal women on redox status, with special reference to bone mineral density (BMD). A total of 90 women were included in the study, 42 with RA and 48 age-matched healthy controls. They were divided into subgroups according to the presence of menopause. Following oxidative stress parameters were measured spectrophotometrically: index of lipid peroxidation (measured as TBARS), nitrites (NO2 -), superoxide anion radical (O2 -), hydrogen peroxide (H2O2), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH). BMD was assessed by using a dual-energy X-ray absorptiometry scanner. Comorbidities and drug history were recorded. The levels of H2O2 and TBARS were elevated in patients with RA, while NO2 - and O2 - increased in healthy women, both in premenopausal and postmenopausal groups. SOD activity decreased in postmenopausal RA patients. BMD was reduced in postmenopausal RA women. There was a correlation between NO2 - and O2 - with Health Assessment Questionnaire (HAQ) index in RA patients. Given that postmenopausal state was associated with elevated oxidative stress within healthy women and that menopausal state did not affect redox homeostasis within RA patients, but the redox homeostasis was altered in both RA groups compared to healthy women, it can be presumed that impaired redox status in RA occurred due to presence of the disease, irrespective of age. Moreover, menopause attenuates BMD reduction in women with RA. These results may indicate the need for therapeutic use of antioxidants in the form of supplements in women with RA, regardless of age.

Clinical Characteristics of Chinese Male Patients with Aquaporin-4 Antibody-Positive Late-Onset Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND OBJECTIVE

Limited studies are available for male patients with anti-aquaporin-4 antibody (AQP4-Ab)-positive late-onset neuromyelitis optica spectrum disease (LONMOSD). The aim of this study was to investigate the clinical characteristics of Chinese male patients with AQP4-Ab-positive LONMOSD.

METHODS

We retrospectively reviewed the medical records of 12 male patients with LONMOSD, 16 male patients with early-onset NMOSD (EONMOSD), and 64 female patients with LONMOSD. These enrolled patients were classified according to the age of onset: LONMOSD (≥50 years of age at onset) versus EONMOSD (<50 years of age at onset). Clinical characteristics and magnetic resonance imaging (MRI) findings were collected. All included patients were positive for AQP4 antibody.

RESULTS

Compared with female LONMOSD patients, male LONMOSD patients had less frequent transverse myelitis (TM) at onset (8.33 vs. 53.13%, p = 0.004) and lower Expanded Disability Status Scale (EDSS) scores (median 1 vs. 4, p = 0.036). Compared with male EONMOSD patients, male LONMOSD patients had a shorter time from onset to diagnosis (0.85 months vs. 6.00 months, p = 0.04).

CONCLUSION

Less common TM at onset, less disease severity, and shorter time from onset to diagnosis probably occur in male LONMOSD patients.

Gender Differences in Rheumatoid Arthritis: Interleukin-4 Plays an Important Role

Introduction

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by symmetrical peripheral polyarthritis. A large number of studies have shown that RA is characterized by gender differences in clinical manifestations. The purpose of this study is to identify the key molecules of gender differences in patients with RA and to provide new molecular targets for personalized therapy. Material and Methods. The data from GSE55457 were downloaded from the comprehensive gene expression comprehensive database, and two groups (RA vs. No-RA groups, Male-RA vs. Female-RA groups) of differentially expressed genes (EDGs) were obtained by GEO2R. The GO function and KEGG pathway analyses of DEGs were carried out through the plug-in ClueGO in Cytoscape. Based on the STRING online, a protein-protein interaction (PPI) network was constructed. Hub genes were selected from CytoHubba. Through the intersection of the top 10 hub genes in two sets of EDGs, the key genes and related KEGG pathways were found. Quantitative Real-Time PCR and Western blotting analysis were performed for verification.

Results

1230 DEGs were screened between RA and No-RA groups, and 306 DEGs were screened between male and female RA groups. The common key gene of the two groups is IL-4. Between RA group and No-RA group, interleukin-4 (IL-4) participates in cytokine-cytokine receptor interaction, Th1 and Th2 cell differentiation, Th17 cell differentiation, T cell receptor signaling pathway, etc.

Conclusion

This study contributes to the molecular biological mechanism of gender differences in RA. IL-4 may have played an important role.

Biomarkers to Personalize the Treatment of Rheumatoid Arthritis: Focus on Autoantibodies and Pharmacogenetics

Rheumatoid arthritis (RA) is a chronic inflammatory disease that is very complex and heterogeneous. If not adequately treated, RA patients are likely to manifest excess of morbidity and disability with an important impact on the quality of life. Pharmacological treatment is based on the administration of the disease-modifying antirheumatic drugs (DMARDs), subdivided into conventional synthetic (csDMARDs), targeted synthetic (tsDMARDs), and biological (bDMARDs). bDMARDs are now frequently administered in patients, both as alternative treatment and together with csDMARDs. Unfortunately, there is a therapeutic response variability both to old and new drugs. Therefore, to identify pre-therapeutic and on-treatment predictors of response is a priority. This review aims to summarize recent advances in understanding the causes of the variability in treatment response in RA, with particular attention to predictive potential of autoantibodies and DMARD pharmacogenetics. In recent years, several biomarkers have been proposed to personalize the therapy. Unfortunately, a magic bullet does not exist, as many factors concur to disease susceptibility and treatment outcomes, acting around the patient’s congenital background. Models integrating demographic, clinical, biochemical, and genetic data are needed to enhance the predictive capacity of specific factors singularly considered to optimize RA treatment in light of multidisciplinary patient management.

Relationship between dietary magnesium intake and rheumatoid arthritis in US women: a cross-sectional study

OBJECTIVES

Diet has been shown to be associated with rheumatoid arthritis (RA), and magnesium has been shown to inhibit inflammatory responses, but research on the relationship between dietary magnesium and RA is limited and controversial. In this study, we aimed to explore the non-linear relationship between dietary magnesium intake and RA in US women.

DESIGN

Cross-sectional survey.

SETTING

National Health and Nutrition Examination Survey (NHANES).

PRIMARY AND SECONDARY OUTCOME MEASURES

Non-linear relationship between dietary magnesium intake and prevalence of RA.

PARTICIPANTS

A total of 13 324 women aged 18-80 years (RA n=12 306, non-RA n=1018) were included in this study.

RESULTS

Overall, the absolute risk (AR) of RA was 7.24% in all participants. In the multivariable logistic regression analysis, we found a negative correlation between dietary magnesium intake and RA (OR=0.84, 95% CI 0.75 to 0.95, p=0.006). When we converted dietary magnesium intake into a categorical variable (tertiles), the ARs of the low group, the middle group and the high group were 9%, 7.1% and 4.9%, respectively. We noticed that the ORs between the three groups were not equidistant; then, we detected a U-shaped linking by smooth curve fitting and obtained inflection points at 181 and 446 mg/day. The prevalence of RA decreased when dietary magnesium intake was <181 mg/day (OR=0.7, 95% CI 0.5 to 0.8, p<0.001) and increased when it was >446 mg/day (OR=2.8, 95% CI 1.2 to 6.6, p=0.020), remaining at a minimum when it was between 181 and 446 mg/day (OR=1.0, 95% CI 0.7 to 1.2, p=0.700).

CONCLUSION

There was a U-shaped relationship between dietary magnesium and RA in women, and our study highlights the importance of moderate dietary magnesium intake in possibly exerting a protective role in women with RA.