Disease activity in psoriatic arthritis (PsA) is positively correlated with body adiposity, saturated fat consumption, and serum cholesterol levels, according to study results published in Lipids in Health and Disease.
Investigators conducted a cross-sectional study of patients who were diagnosed with PsA using the Classification Criteria of Psoriatic Arthritis. Enrollees underwent whole-body dual x-ray absorptiometry, which captured total lean mass, skeletal lean mass, total and regional adipose tissue, total bone mineral density, and bone mineral content. Patients also completed a 3-day food inventory that quantified the intake of fats, protein, and other nutrients. Fasting blood samples were obtained and tested for C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), hemoglobin A1c, fasting insulin and glucose levels, cholesterol, and triglycerides. Skin disease was evaluated using the Psoriasis Area and Severity Index and by evaluating body surface area of involvement. Joint activity was assessed using the 28-joint Disease Activity Score. Multivariate regression was performed to identify predictors of joint and skin disease activity.
A total of 97 patients with PsA were enrolled, of whom 53 (54.6%) were women. Mean age was 53.12±13.10 years. Excess fat mass (92.7%) and metabolic syndrome (54.6%) were highly prevalent in the sample, although lean mass and bone mass were not significantly impaired.
Disease activity in the peripheral joints, measured by disease scores relating to either CRP or ESR, was positively correlated with total body fat, fat mass index, body mass index, and waist circumference (all P <.05) and negatively correlated with appendicular skeletal lean muscle mass (P <.001).
Skin disease activity was positively associated with total cholesterol (P =.003) and low-density lipoprotein cholesterol levels (P =.006). In addition, skin disease activity was more severe in patients with increased trans fat and sodium consumption and lower omega-6 consumption. However, skin disease activity was not significantly associated with any body composition measurements. After adjustments for sex, body mass index, and age, patients with severe joint disease activity had greater fat mass (P =.02) and insulin resistance (P =.016) than patients in remission or with low disease activity. These results demonstrated a possible link between PsA disease severity and interrupted glucose and lipid metabolism.
With regard to study limitations, investigators cited the small sample size, lack of a control group, and variations in food intake, which may not have been captured by a 3-day registry.
However, these results underscore a harmful association between fat and disease activity in PsA.
Leite BF, Morimoto MA, Gomes C, et al. Higher bodily adiposity, fat intake, and cholesterol serum levels are associated with higher disease activity in psoriatic arthritis patients: is there a link among fat and skin and joint involvement? Lipids Health Dis. 2020;19(1):21.