Obesity Linked With Lower QOL, Greater Disease Burden in Patients With Psoriatic Arthritis

Obesity may significantly affect quality of life (QOL) and disease burden in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA), according to study findings published last week in the Journal of Clinical Medicine.

As a low-grade systemic inflammatory condition, obesity has been suggested to share a common pathological pathway with immune-mediated inflammatory rheumatic diseases, noted researchers. In fact, patients with PsA and RA have been shown to have a higher prevalence of obesity compared with the general population, with disease management of both conditions indicated to be potentially impaired by obesity or high body mass index (BMI).

Although prior associations have been made regarding abnormal BMI and worse rheumatic markers, the study authors said that epidemiological studies using real-world data and clinical studies in patients with PsA and RA have rarely stratified for BMI, body weight, or body fat distribution.

Seeking to assess clinical differences across BMI categories, they conducted a descriptive study of patients with PsA (n = 819) and RA (n = 3217) registered in the Swiss Clinical Quality Management in Rheumatic Diseases database who were new users of biologic or targeted synthetic disease-modifying antirheumatic drugs.

Participants were stratified by BMI at treatment onset according to World Health Organization classification (underweight [BMI < 18.5], normal weight [BMI 18.5-24.9], overweight [BMI 25.0-29.9], and obese [BMI ≥ 30]), with underweight and normal weight categories merged for patients with PsA. Normal weight participants were set as the reference group:

• patients with RA (underweight, n = 142; normal weight, n = 1505; overweight, n = 1024; obese, n = 546)
• patients with PsA (normal weight, n = 325; overweight, n = 299; obese, n = 195)

In assessing the study cohort, prevalence of overweight and obesity was found to be greater in male and female patients with RA and PsA compared with the general population. Compared with the reference normal weight group, patients with PsA who were obese had significantly higher C-reactive protein (CRP) (P = .020) and worse body function and QOL, as measured by surveys such as the Health Assessment Questionnaire and Dermatology Life Quality Index.

Patients with PsA classified as obese or overweight also presented with significantly worse disease activity according to disease activity index for PsA scores (overweight: mean [SD], 27.03 [17.81]; P = .022; obese: mean [SD], 26.90 [15.33]; P = 0.037).

Along with patients with PsA, those with RA presented with significantly higher CRP, worse disease activity, and lower QOL (P < .05).

“Obese patients with PsA had significantly worse skin manifestation and pain,” added researchers. “While obese patients with RA had significantly higher erythrocyte sedimentation rate and tender joint counts, as well as lower seropositive prevalence.”

Reference

Vallejo-Yagüe E, Burkard T, Möller B. Finckh A, Burden AM. Comparison of psoriatic arthritis and rheumatoid arthritis patients across body mass index categories in Switzerland. J Clin Med. Published online July 20, 2021. doi:10.3390/jcm10143194