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

Abstract

Abnormal body mass index (BMI) was associated with worse rheumatic markers in psoriatic arthritis (PsA) and rheumatoid arthritis (RA). Aiming to describe PsA and RA patients stratified by BMI, we performed a descriptive study in PsA and RA patients (two distinct cohorts) in the Swiss Clinical Quality Management in Rheumatic Diseases (SCQM) registry. New users of biologic or targeted synthetic disease-modifying anti-rheumatic drugs (b/tsDMARDs) were stratified by BMI at the start of their treatment (underweight, normal weight, overweight, obese). The PsA underweight and normal weight categories were merged. Age at disease onset and further characteristics at the start of the first b/tsDMARD treatment were compared across BMI categories vs. the corresponding normal weight group. The study included 819 PsA (36.5% overweight, 23.8% obese) and 3217 RA patients (4.4% underweight, 31.8% overweight, 17.0% obese). Compared to the corresponding normal weight group, PsA and RA obese patients had significantly (p < 0.05) higher C-reactive protein, worse disease activity, and lower quality of life (QoL). Obese PsA patients had significantly worse skin manifestation and pain, while obese RA patients had significantly higher erythrocyte sedimentation rate and tender joint counts, as well as lower seropositive prevalence. To conclude, obese PsA and RA patients presented worse disease activity and poorer QoL than those with normal weight.

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

“…Finally, as described elsewhere, 12 the prevalence of overweight and obesity were higher among patients with PsA in comparison to the general population in Switzerland (Switzerland 2017, people >15 years old, 31% overweight and 11% obese). 36 Higher obesity prevalence among patients with PsA in comparison to the reference population was in agreement with prior studies.…”

“…Additionally, we classified patients with BMI <25 kg/m 2 as normal weight, including patients with BMI <18.5 kg/m 2 , who may be classified as underweight. This was done due to low prevalence of underweight patients with PsA in SCQM 12 and is consistent with previous practice in PsA 10 26 and other inflammatory rheumatic diseases research in which the majority of studies combine normal and underweight patients. 41 It was suggested that patients with obesity may benefit from other non-TNFi b/tsDMARDs, however, the evidence is limited.…”

“…36 Higher obesity prevalence among patients with PsA in comparison to the reference population was in agreement with prior studies. 12 …”

“…6 One of the most common comorbidities in patients with PsA is obesity, 1 8 and higher prevalence of obesity has been reported among patients with PsA (23%-37%) compared with the general population. [9][10][11][12] Among patients with PsA, obesity has been associated to lower probability of achieving MDA compared with patients with normal weight. 10 13 14 Similarly, patients with obesity who have PsA treated with tumour necrosis factor alfa inhibitors (TNFi) showed higher risk of treatment discontinuation compared with patients without obesity, 15 as well as lower odds of achieving treatment response compared with patients without obesity 15 or normal weight patients.…”

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

“…Rheumatoid arthritis (RA), with a prevalence of 0.5 to 1.0% [ 1 ], affects women three times more frequently than men [ 2 , 3 ]. While the reason for this unbalanced frequency between women and men is not fully understood, it is known as the result from multiple factors, including both biologically-driven sex concepts and socially constructed gender factors.…”