Abnormal serum fatty acid profile in psoriatic arthritis

Abstract

Introduction: Psoriatic arthritis (PsA) is a chronic inflammatory disease associated with higher risk of cardiovascular events and metabolic syndrome than psoriasis without arthritis. Fatty acids (FA) play an important role as signaling molecules in inflammatory and metabolic pathways. The aim of the study was to evaluate serum FA concentration in patients with PsA and to investigate the correlations of FA with the clinical and biochemical markers.

Material and methods: We measured 14 FA serum concentrations by gas-liquid chromatography and flame-ionization detector after direct transesterification in 54 psoriatic patients (including 14 PsA patients) and 32 healthy controls. FA were divided according to their biologic properties into: saturated FA (SFA) and unsaturated FA (UFA), subdivided into monounsaturated FA (MUFA) and polyunsaturated FA (PUFA).

Results: The results were correlated with Psoriasis Area and Severity Index (PASI), inflammatory and biochemical markers and lipid profile. We observed an abnormal FA profile in both psoriasis and PsA. We demonstrated lower concentrations of 10 FA in psoriasis and 7 in PsA. Patients with joint disease had a significantly higher percentage of SFA (p = 0.016) and MUFA (p = 0.001) and lower percentage of PUFA (p < 0.001) than the control group. The SFA/UFA ratio was significantly higher (p = 0.02) in PsA than in psoriasis and the controls. In the group of PsA the concentrations of docosahexaenoic acid (DHA) (p = 0.027) and n-3 PUFA (p = 0.031) correlated inversely with PASI.

Conclusions: Our findings indicate a changed FA profile both in psoriasis and PsA and reflect metabolic status that may predispose to the development of metabolic syndrome.

Keywords: docosahexaenoic acid; metabolic syndrome; monounsaturated fatty acids; polyunsaturated fatty acids; psoriasis.

Figure 1

Comparison of FA pattern in psoriatic patients (Ps), psoriatic arthritis (PsA) and the control group (Ctrl). Data are shown as median and quartiles. Significant differences between the psoriatic groups and the controls are shown as: *p < 0.05; **p < 0.01; ***p < 0.001. Significant differences between the psoriatic subgroups (Ps vs. PsA) are shown as ^#p < 0.05; ^##p < 0.01 MUFA – monounsaturated fatty acids, PUFA – polyunsaturated fatty acids, SFA – saturated fatty acids, UFA – unsaturated fatty acids.

Figure 2

Scatterplot of correlation of docosahexaenoic acid (DHA) and PASI (Psoriasis Area and Severity Index) (A) and n-3 polyunsaturated fatty acid (n-3 PUFA) and PASI in psoriatic arthritis (n = 40) (B)