Comparison of Psoriatic Arthritis and Rheumatoid Arthritis Patients across Body Mass Index Categories in Switzerland

Weight loss affects disease activity and treatment response in inflammatory rheumatic diseases

The quantity and quality of the adipose tissue is altered in obesity: hypertrophy of adipocytes, decrease in expandability, fibrosis, production of pro-inflammatory cytokines and adipokines, inflammatory infiltration by pro-inflammatory M1 macrophages and T lymphocytes. Excess adipose tissue and obesity are associated with low-grade inflammation that can aggravate chronic inflammatory diseases, decrease treatment efficacy, contribute to the development of comorbidities, and of the disease in its preclinical phase. Obesity increases the incidence of rheumatoid arthritis (RA), psoriasis, psoriatic arthritis with a weight-dose effect. It is also a predictor of worse response to treatment, in particular TNF inhibitors. Weight loss induced by bariatric surgery decreases the risk of psoriasis and psoriatic arthritis and improves disease activity and remission in RA. A 5% weight loss through a low-calorie diet improves the response to TNF inhibitors in psoriatic arthritis, losing even more weight improves the response even more. In RA, the beneficial effect of weight loss from a low-calorie diet on disease activity has been reported in a few observational studies but has not been demonstrated in a randomized controlled trial. Screening and management of obesity are part of the dietary recommendations of the French Society for Rheumatology in patients with chronic inflammatory rheumatic diseases. Of course, this should be combined with other lifestyle modifications such as smoking cessation, higher food quality, increased physical activity and reduced sedentary behavior.

Comparative effectiveness of biologics in patients with rheumatoid arthritis stratified by body mass index: a cohort study in a Swiss registry

OBJECTIVES

Obesity is associated with lower treatment response in patients with rheumatoid arthritis (RA). In patients with obesity, abatacept was suggested as a preferable option to tumour necrosis factor-alpha inhibitors. We aimed to assess the comparative effectiveness of etanercept, infliximab and abatacept, compared with adalimumab, in patients with RA with obesity. Secondarily, we also investigated this in patients with overweight and normal weight for completeness.

DESIGN

Observational cohort study.

SETTING

Swiss Clinical Quality Management in Rheumatic Diseases (SCQM) registry (1997-2019).

PARTICIPANTS

Adult patients with RA from the SCQM registry who received etanercept, infliximab, abatacept or adalimumab as their first biological or targeted synthetic disease-modifying antirheumatic drug were classified based on their body mass index (BMI) at the start of that treatment in three cohorts: obese, overweight, normal weight. They were followed for a maximum of 1 year.

EXPOSURE

The study exposure of interest was the patients' first biological, particularly: etanercept, infliximab and abatacept, compared with adalimumab.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary study outcome was remission within 12 months, defined as 28-joint Disease Activity Score (DAS28) <2.6. Missingness was addressed using confounder-adjusted response rate with attrition correction. Logistic regression was used to compare the effectiveness of etanercept, infliximab and abatacept versus adalimumab. Each BMI cohort was addressed and analysed separately.

RESULTS

The study included 443 obese, 829 overweight and 1243 normal weight patients with RA. There were no statistically significant differences in the odds of DAS28-remission at ≤12 months for etanercept, infliximab and abatacept, compared with adalimumab, in any of the BMI cohorts.

CONCLUSIONS

No differences in DAS28-remission were found between the study drugs and adalimumab as first biologic in patients with RA, independently of the BMI cohort. We did not find evidence that treatment with abatacept increased the likelihood of remission compared with adalimumab among obese patients with RA.

Ideal cardiovascular health metrics have better identification of arthritis

BACKGROUND

This study aimed to explore the association between ideal cardiovascular health metrics (ICVHM) and arthritis (AR), as well as the interactions of various indicators in ICVHM on AR in US adults.

METHODS

We involved 17,041 participants who were interviewed by NHANES from 2011 to 2018. AR included osteoarthritis or degenerative arthritis (OA), rheumatoid arthritis (RA), and psoriatic arthritis and other arthritis (Other AR). Logistic regression was applied to analyze the association between AR and ICVHM. Mixed graphical model (MGM) was used to explore the interaction between variables in ICVHM.

RESULTS

Higher ICVHM scores had a protective effect on AR. Compared to "≤1" score, the ORs of AR in participants with 2, 3, 4, and ≥5 were 0.586, 0.472, 0.259, and 0.130, respectively. Similar results were also found in different types of AR. ICVHM has a maximum area under the curve value of 0.765 and the interaction between blood pressure and total cholesterol was 0.43.

CONCLUSIONS

ICVHM correlates significantly with AR and is better at identifying AR than individual indicators. ICVHM can be better improved by controlling the indicators with stronger interactions. Our findings provide guidance for promoting health factors, which have important implications for identification and prevention of AR.

Longitudinal associations between body mass index and changes in disease activity and radiographic progression in rheumatoid arthritis patients treated with infliximab

OBJECTIVES

Treatment response is worse in obese patients with rheumatoid arthritis (RA), including patients on weight-adjusted therapies like infliximab. We aimed to assess the association between body mass index (BMI) and changes in RA disease activity and radiographic progression over time.

METHODS

We included infliximab users with an RA diagnosis in the Swiss Clinical Quality Management in Rheumatic Diseases registry (1997-2020). Two cohorts were defined: (1) starting from their first BMI measurement or disease activity score (DAS28-esr), and (2) from their first BMI measurement or radiographic assessment (Rau score). We evaluated the coefficient and 95% CI of BMI with changes in mean DAS28-esr (cohort 1) and mean Rau scores (a structural joint damage score, cohort 2) using generalised estimation equations, overall and stratified by BMI categories.

RESULTS

Cohort 1 comprised 412 patients (74% women, mean age 53 years, mean BMI 25). We observed no change in mean DAS28-esr with increasing BMI overall (adjusted coefficient: 0.00, 95% CI -0.02 to 0.02), or in BMI categories. Cohort 2 comprised 187 patients highly alike to those in cohort 1. We observed a significant decrease of 1.05 in mean Rau scores for every increase in BMI unit (adjusted coefficient: -1.05, 95% CI -1.92 to -0.19). Results remained statistically non-significant across BMI categories.

CONCLUSIONS

Our longitudinal investigation suggests that BMI increase may not lead to changes in DAS28-esr in patients receiving infliximab, despite the weight-adapted dose. Yet, there may be a decrease in erosions with increasing weight non-limited to obese patients.

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.

Minimal disease activity and remission in patients with psoriatic arthritis with elevated body mass index: an observational cohort study in the Swiss Clinical Quality Management cohort

OBJECTIVE

To assess the impact of elevated body mass index (BMI) in the achievement of minimal disease activity (MDA) and several definitions of remission in patients with psoriatic arthritis (PsA) in Switzerland. Secondarily, to assess the overlapping across the study outcomes.

METHODS

This observational cohort study in the Swiss Clinical Quality Management in Rheumatic Diseases (SCQM) registry included patients with PsA starting their first biologic or targeted synthetic disease-modifying antirheumatic drug (b/tsDMARD) from 1997 to 30 June 2018. Exposure was BMI category at b/tsDMARD start: overweight, obese, and normal weight (reference). Logistic regression was used to assess the achievement of MDA and remission at ≤12 months, as well as treatment persistence at 1 year, in overweight patients and patients with obesity compared with the normal weight group. Remission was defined by Disease Activity for Psoriatic Arthritis (DAPSA), clinical DAPSA (cDAPSA) and 28-joint Disease Activity Score (DAS28). Additionally, overlapping across study outcomes was investigated.

RESULTS

The study included 306 (39.5%) normal weight patients, 285 (36.8%) overweight patients and 183 (23.6%) patients with obesity. Compared with the normal weight group, patients with obesity had lower odds of achieving MDA at ≤12 months (adjusted OR (ORadj) 0.45, 95% CI 0.24 to 0.82). This was consistent with the observed reduced odds of achieving DAPSA-remission (ORadj 0.42, 95% CI 0.21 to 0.85), cDAPSA-remission (ORadj 0.51, 95% CI 0.27 to 0.96) and DAS28-remission (ORadj 0.51, 95% CI 0.32 to 0.81) in patients with obesity versus normal weight patients. Among the 125 patients achieving MDA, the majority (81.8% normal weight, 80.0% overweight, 78.9% obese) achieved cDAPSA-remission. No differences were observed in the odds to achieving treatment persistence between the BMI strata.

CONCLUSIONS

Obesity halved the likelihood of achieving MDA and remission in patients with PsA with b/tsDMARDs compared with those with normal weight, while it did not impact treatment persistence. High overlapping of patients achieving the outcomes MDA and cDAPSA-remission was observed across every BMI group.