Obesity More Common in Those With Psoriasis Alone Compared With Those With Wider Disease

A new study said that while obesity is frequently observed in patients with psoriatic disease, it is even more common in those who have only psoriasis alone. The researchers said that patients with axial forms of psoriatic arthritis (PsA) should receive special attention in order to preserve their physical function with anti-inflammatory treatments, and healthy lifestyles should be encouraged.

Psoriatic disease refers to a systemic issue that affects more than just the skin and joints to include cardiovascular comorbidity, osteoporosis, ocular inflammation, intestinal inflammation, and liver disease.

This study sought to analyze the frequency and obesity-associated factors in a cohort of PsA; obesity is a common cardiovascular risk factor in psoriatic disease and while the prevalence is high, the factors associated with it in patients with PsA are poorly understood. Are overweight and obesity intrinsic traits of psoriatic disease itself, or comorbidities? Is obesity more prevalent in patients with psoriasis because painful, swollen joints make activity difficult?

This retrospective cross-sectional study included 290 consecutive patients treated at a single university hospital who fulfilled the ClASsification for Psoriatic ARthritis (CASPAR) criteria for PsA. The group included 159 men (54.8%) and 131 women (45.2%), with an average age of 54, with a range of 24 to 82; the mean follow-up time was 7.2 years. Investigators described the joint patterns, both at the beginning of the disease and as it evolved, and categorized patients into oligoarthritis (patients with 4 or less swollen joints) and polyarthritis (those with 5 or more swollen joints).

Patients with axial disease were classified according to the Assessment of SpondyloArthritis International Society criteria for axial spondyloarthritis. Patients were stratified in early- and late-onset disease according to a cut-off point of 40 years. For comparison, researchers included 310 patients with psoriasis but without arthritis and 600 outpatients without inflammatory conditions.

Among other things, researchers collected data regarding skin disease, including the main type of psoriasis, the location of lesions, nail disease, and the percentage of patients with the involvement of 3 or more body areas. Use of glucocorticoids, nonsteroidal anti-inflammatory drugs, and conventional as well as biologic disease-modifying antirheumatic drugs (DMARDS) was also collected.

Obesity was more common both in psoriasis (36.5% vs 22%, odds ratio [OR] 2.1; 95% CI, 1.5-2.8), P < .01) and PsA (27.6% vs 22%, OR 1.4; 95% CI, 1.0-1.9], P < .05) than in the non-inflammatory population. But obesity was more frequent in psoriasis (36.5%) than in PsA (27.6%) (OR 1.5; 95% CI, 1.1 to 2.1, P < .05).

After correcting for age, sex, disease duration, and other confounders, independent associations with obesity (P < .05) were: PsA family history (OR 3.6; 95% CI, 1.1-12.4), evolution as axial disease (OR 4.4; 95% CI, 1.0-15.4), and dyslipidemia (OR 3.5; 95% CI, 1.5-8.6).

Hypertension and dyslipidemia were more common in patients with arthritis, while other cardiovascular risk factors, such as smoking or obesity itself, were more prevalent in patients with psoriasis without arthritis. Some risk factors were more prevalent in patients with psoriatic disease than in the non-inflammatory population, confirming earlier findings.

In discussing the results, the authors said obesity is associated with lower retention and response rates to DMARDs; other evidence indicates that losing weight in patients with PsA is associated with an increased likelihood of minimal disease activity in patients treated with anti-tumor necrosis factor therapy.

While most cardiovascular risk factors tend to occur in patients whose psoriasis or arthritis begins after age 40, when age is corrected in regression analysis models, psoriasis itself, or arthritis, continue to contribute differentially to the presence of these factors. The researchers said they have previously found an association between hypertension and arthritis of onset above age 40, and between diabetes and psoriasis above that age limit. They said the current findings reinforce the idea that psoriatic disease itself contributes to the increase of cardiovascular risk, more than age and other factors.

Reference

Queiro R, Lorenzo A, Tejón P, Coto P, Pardo E. Obesity in psoriatic arthritis: Comparative prevalence and associated factors. Medicine. 2019;98(28):e16400. doi:10.1097/MD.0000000000016400.