Obesity and the prediction of minimal disease activity: a prospective study in psoriatic arthritis

We prospectively evaluated whether obesity impacts achievement of minimal disease activity (MDA) in subjects with psoriatic arthritis (PsA).

Among PsA subjects with an active disease and who were starting a treatment with tumor necrosis factor α blockers, 135 obese (body mass index [BMI] >30 kg/m(2) ) patients and 135 patients of normal weight (controls) were followed up for 24 months. At baseline and at the 12- and 24-month followup, all subjects underwent a clinical, rheumatologic, and laboratory assessment.

With the exception of the prevalence of hypercholesterolemia and hypertriglyceridemia, case and control subjects were similar for all the clinical and demographic characteristics analyzed. At the 12-month followup, in both cases and controls, no significant changes in body weight were found (P > 0.05 for all). MDA was achieved by 98 (36.3%) of the 270 PsA individuals. The prevalence of obesity was higher in those that did not achieve MDA than in those that did (64.0% versus 25.5%; P < 0.001). After adjusting for all the other variables, obesity was associated with a higher risk of not achieving MDA (hazard ratio [HR] 4.90, 95% confidence interval [95% CI] 3.04-7.87; P < 0.001). The HR of not achieving MDA was 3.98 (95% CI 1.96-8.06, P < 0.001) and 5.40 (95% CI 3.09-9.43, P < 0.001) in subjects with first-degree (BMI <30 kg/m(2) ) and second-degree (BMI 30-35 kg/m(2) ) obesity, respectively. Among the 98 subjects who had achieved MDA at the 12-month followup, the presence of obesity was associated with a poor probability of sustained MDA at the 24-month followup (HR 2.04, 95% CI 1.015-3.61; P = 0.014).

Obesity is a negative predictor of achieving and maintaining MDA.