Modifiable risk factors and the development of psoriatic arthritis in people with psoriasis

Abstract

Summary Background Psoriatic arthritis (PsA) is a progressive and often destructive joint disease affecting approximately 20% of people with psoriasis. Objectives To investigate associations between obesity, changes in body mass index (BMI), alcohol intake and smoking status and the development of PsA in people with psoriasis. Methods We undertook a cohort study involving incident cases of psoriasis identified from the U.K. Clinical Practice Research Datalink between 1998 and 2014. The associations between smoking, alcohol and BMI and development of PsA were assessed using generalized additive models. Additionally, the risks associated with a change in BMI during follow‐up were investigated using distributed lag nonlinear models. Results We identified 90 189 incident cases of psoriasis (42% male, mean age 51 years), of whom 1409 had a subsequent record of PsA diagnosis. BMIs of 25·0–29·9, 30·0–34·9 and ≥ 35·0 kg m−2 were significantly associated with an increased risk of developing PsA compared with BMIs < 25·0 kg m−2: adjusted odds ratios (95% confidence intervals) 1·79 (1·46–2·19), 2·10 (1·67–2·63) and 2·68 (2·09–3·43), respectively. Reducing BMI over a 10‐year period (linearly) was associated with a reduction in the risk of developing PsA compared with BMI remaining constant over the same period. Increased risks of developing PsA were associated with moderate drinking but not with former or heavy drinking or with current or past smoking status. Conclusions In this incident psoriasis cohort, increased BMI and moderate drinking, but not heavy drinking or smoking status, were associated with an increased risk of PsA in people with psoriasis. Importantly, we have shown that reducing weight may result in a reduction in the risk of developing PsA. What's already known about this topic? There is some evidence that increased body mass index is associated with an increased risk of developing psoriatic arthritis. There are conflicting results surrounding the relationship between smoking and the development of psoriatic arthritis among patients with psoriasis. What does this study add? Using a nonlinear and lagged effect of body mass index measured over time we have shown that reducing body mass index may be associated with a reduction in the risk of developing psoriatic arthritis. We have found no evidence that smoking alters the risk of developing psoriatic arthritis in patients with psoriasis.

Obesity and Psoriatic Arthritis: A Narrative Review

“…In fact, among patients with psoriasis, a reduction in BMI may reduce the risk of PsA. A large PsA cohort study found that reducing BMI over a 10-year period was associated with a reduction in the risk of developing PsA compared with BMI remaining constant over the same period [ 55 ]. Patients with PsA are at a higher risk for cardiovascular disease including myocardial infarction and major adverse cardiovascular events (MACE) after accounting for traditional cardiovascular risk factors [ 3 , 56 , 57 ].…”

Weight loss is associated with sustained improvement of disease activity and cardiovascular risk factors in patients with psoriatic arthritis and obesity: a prospective intervention study with two years of follow-up

“…Obesity, diabetes, hypertension, hyperlipidemia and the metabolic syndrome (MetS) are overrepresented in both psoriasis and PsA [2][3][4] and the patients are at increased risk of cardiovascular morbidity [5][6][7][8][9]. Studies indicate that obesity may play a pathophysiologic role in psoriasis and PsA, since obesity is associated with an increased risk of developing these conditions [10][11][12][13]. Obesity is also associated with increased disease activity [14,15] and poorer effect of treatment [16][17][18][19].…”

The need for strategies to address obesity and psoriatic arthritis prevention in psoriasis

“…body mass index) changes the outcome, this study provides further supporting obesity as a causal risk factor for PsA. 3 Now comes the hard work: putting this knowledge into action. This new evidence supports two important future needs: (i) the need for mechanisms to help our patients to lose weight and (ii) the need for PsA prevention trials in psoriasis.…”

“…In demonstrating that changing the level of the risk factor (i.e. body mass index) changes the outcome, this study provides further supporting obesity as a causal risk factor for PsA . Now comes the hard work: putting this knowledge into action.…”