Weight loss is associated with sustained improvement of disease activity and cardiovascular (CV) risk factors in patients with psoriatic arthritis (PsA) and obesity, according to study results published in Arthritis Research & Therapy.
The current prospective cohort study (ClinicalTrials.gov Identifier: NCT02917434) included patients with PsA and obesity from rheumatology clinics around Sweden. Inclusion criteria were 25 to 75 years of age; clinical PsA diagnosis; and a body mass index (BMI) of 33 or more. Patients received treatment with Very Low Energy Liquid Diet (VLED) during 12 or 16 weeks, followed by a structured reintroduction of food. Patients with PsA were age- and sex-matched with control participants without PsA who were also receiving VLED for obesity treatment. Participants underwent clinical examination at baseline and after 3, 6, 12, and 24 months. Disease activity was measured at each timepoint using various clinical measures, including 66/68 swollen/tender joints count, Leeds enthesitis index (LEI), C-reactive protein (CRP) levels, and Health Assessment Questionnaire (HAQ). All participants received BMI assessment and provided fasting blood samples at 12 and 24 months.
A total of 46 patients with PsA received VLED treatment, among whom 39 and 35 attended the 12- and 24-month visits, respectively. Patients who did not complete follow-up (n=11) were younger than those who continued the study (P =.005), though other characteristics were comparable between groups. At month 12, median weight loss among patients was 16.0% (interquartile range [IQR], 10.5%-22.4%) of baseline body weight. At month 24, median weight loss was 7.4% of initial body weight (IQR, 5.1%-14.0%). Swollen and tender joints count, LEI, CRP levels, and HAQ scores were all significantly reduced at the 12- and 24-month follow-up vs baseline. The number of patients with Minimal Disease Activity increased from 28.2% (n=11/39) at baseline to 38.5% (n=15/39; P =.008) at 12 months and 45.7% (n=16/35; P =.016) at 24 months.
Weight loss was also associated with improved CV and metabolic measures, including serum lipid, glucose, and urate levels. Antihypertensive treatment was stopped or reduced in 5 patients during follow-up.
Of the 52 control participants who received VLED treatment, 42 attended the 6-month visit and 39 attended the 12-month visit. Patients and control participants achieved similar degrees of weight loss at 6 and 12 months (P =.280). Mean changes in BMI, CRP, and serum urate were also similar among both groups.
The primary study limitation was the nonrandomized design; an untreated group of patients with PsA may have provided more information about the efficacy of VLED. However, a matched control group of patients without PsA also supported the benefits of VLED and weight loss.
“The results of the study provide support to the hypothesis of obesity as a promotor of disease activity in PsA and shows what can be achieved by 5% [to] 15% weight loss in patients with PsA and obesity,” the investigators concluded.
Klingberg E, Björkman S, Eliasson B, Larsson I, Bilberg A. 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. Arthritis Res Ther. 2020;22(1):254.