PsA is an axial and/or peripheral inflammatory arthritis associated with psoriasis, included in the group of spondylarthritides. It has been suggested that PsA could be a systemic disease, involving even coronary arteries and the heart. An increased prevalence of vascular risk factors has been found in PsA subjects as compared with the general population and psoriatic subjects. Moreover, PsA patients exhibit an increased prevalence of liver steatosis, a marker of metabolic syndrome, and of obesity. Interestingly, many reports demonstrate that adipose tissue is metabolically active, representing a source of inflammatory mediators, known as adipokines. The latter include TNF-α, macrophage chemoattractant protein-1, plasminogen activator inhibitor-1 (PAI-1), IL-6, leptin and adiponectin, leading to a pro-inflammatory status in obese subjects. This evidence supports the idea of obesity as a low-grade inflammatory disease. Accordingly, obesity might be associated with some rheumatic diseases. In particular, it seems to affect several features of PsA, such as its development, cardiovascular risk and clinical outcome. Recent data suggest that increased BMI in early adulthood increases the risk of PsA development in psoriatic patients, supporting a link between fat-mediated inflammation and joint involvement. Obesity may represent an additive cardio-metabolic risk factor in PsA subjects. Abdominal obesity may also determine an increased risk of not achieving minimal disease activity in PsA patients, highlighting the role of abdominal fat accumulation as a negative predictor of good clinical response to biologic agents. This review assesses the relationship between obesity and PsA according to the available literature.

Enteropathic arthritis (EA) is a spondyloarthritis (SpA) which occurs in patients with inflammatory bowel diseases (IBDs) and other gastrointestinal diseases. Diagnosis is generally established on the medical history and physical examination. It was, generally, made according to the European Spondyloarthropathy Study Group (ESSG) criteria. Rheumatic manifestations are the most frequent extraintestinal findings of IBD with a prevalence between 17% and 39%, and IBD is associated, less frequently, with other rheumatic disease such as rheumatoid arthritis, Sjogren syndrome, Takayasu arteritis, and fibromyalgia. Although the pathogenesis of EA has not been plainly clarified, the most popular theory supposes that joint inflammation occurs in genetically predisposed subjects with bacterial gut infections, provided an important evidence for a possible relationship between inflammation of the gut mucosa and arthritis. The management of patients with EA requires an active cooperation between the gastroenterologist and rheumatologist.

In this study, we evaluated the impact of obesity and/or overweight on the achievement of minimal disease activity (MDA) in patients with psoriatic arthritis (PsA) and patients with rheumatoid arthritis (RA) receiving an anti-rheumatic treatment. Obesity can be considered a low-grade, chronic systemic inflammatory disease and some studies suggested that obese patients with rheumatic diseases exhibit a lower rate of low disease activity achievement during treatment with anti-rheumatic drugs. A systematic search was performed in major electronic databases (PubMed, Web of Science, Scopus, Embase) to identify studies reporting MDA achievement in obese and/or overweight patients with RA or PsA and in normal-weight RA or PsA control subjects. Results were expressed as Odds Ratios (ORs) with pertinent 95% Confidence Intervals (95%CIs). We included 17 studies (10 on RA and 7 on PsA) comprising a total of 6693 patients (1562 with PsA and 5131 with RA) in the analysis. The MDA achievement rate was significantly lower in obese patients than in normal-weight subjects (OR 0.447, 95% CI 0.346–0.577, p < 0.001, I 2 = 62.6%, p < 0.001). Similarly, overweight patients showed a significantly lower prevalence of MDA achievement than normal-weight subjects (OR 0.867, 95% CI 0.757–0.994, p = 0.041, I 2 = 64%, p = 0.007). Interestingly, the effect of obesity on MDA was confirmed when we separately analyzed data on patients with RA and patients with PsA. In contrast, when we evaluated the effect of overweight, our results were confirmed for PsA but not for RA. A meta-regression analysis showed that follow-up duration, age, male sex, and treatment duration are covariates significantly affecting the effect of obesity/overweight on MDA achievement. The results of our meta-analysis suggest that obesity and overweight reduce the chances to achieve MDA in patients with rheumatic diseases receiving treatment with traditional or biologic disease-modifying antirheumatic drugs.

The most common extra-intestinal manifestation in patients with inflammatory bowel disease (IBD) is articular involvement, with a prevalence ranging between 17% and 39%. It is frequently characterized by an involvement of the axial joints but may also be associated with peripheral arthritis. The target of therapy in the management of arthritis associated with IBD is to reduce the inflammation and prevent any disability and/or deformity. This requires active cooperation between gastroenterologist and rheumatologist. The treatment of axial involvement has focused on the combination of exercise with nonsteroidal anti-inflammatory drugs. Immunomodulators have been efficacious in patients with peripheral arthritis and other extra-intestinal manifestations, but they are not effective for the treatment of axial symptoms of spondylitis. Tumor necrosis factor (TNF) α inhibitors have been proven to be highly effective in the treatment of IBD patients which are steroid-dependent or refractory to conventional therapy and in patients with associated articular manifestations. The treatment of peripheral involvement and/or enthesitis and/or dactylitis is based on local steroid injections, while sulfasalazine and/or low doses of systemic steroids may be useful in case of inadequate response to intra-articular steroids. Sulfasalazine induces only a little improvement in peripheral arthritis. Immunomodulators such as methotrexate, azathioprine, cyclosporine and leflunomide show their efficacy in some patients with peripheral arthritis and other extra-intestinal components. TNF-α inhibitors should be considered the first-line therapeutic approach when moderate-to-severe luminal Crohn’s disease or ulcerative colitis is associated with polyarthritis. The aim of this review is to provide a fair summary of current treatment options for the arthritis associated with IBD.