Midtveisevaluering- Inger Marie Skoie

Inger Marie Skoie er tilknyttet Klinisk institutt 1. Veiledere er Roald Omdal, Thomas Ternowitz, Katrine Brække Norheim og Grete Jonsson

Abstract

Chronic fatigue in psoriasis: prevalence and biological mechanisms

Fatigue is prevalent in patients with chronic inflammatory diseases and often rated as the most troublesome aspect of their disease. However,studies are sparse on its occurrence in psoriasis.

In 84 patients with chronic plaque-type psoriasis and 84 age- and gender-matched healthy subjects, fatigue severity was assessed using three different generic fatigue instruments: the fatigue Visual Analogue Scale (fVAS), the Fatigue Severity Scale (FSS), and the Short Form 36 (SF-36) vitality scale. Cut-off scores defined as ≥4 for FSS, ≥50 for fVAS, and ≤35 for SF-36 vitality scale. Disease activity was evaluated using the Psoriasis Area and Severity Index (PASI) and the impact on quality of life (QoL) with the Dermatology Life Quality Index (DLQI).

Nearly 50% of psoriasis patients suffered from substantial fatigue. Fatigue severity was associated with smoking, pain, and depression, but not with psoriasis severity.

One of our hypotheses for fatigue mechanisms is related to cellular stress mechanisms. We have therefore measured markers of oxidative stress. The term “oxidative stress” is used to describe the situation when reactive oxygen species (ROS) dominate over anti-oxidant defense mechanisms. Currently, there are no optimal methods for direct detection of ROS, however indirect measures such as malondialehyde (MDA) and advanced oxidation protein products (AOPP) are considered as good alternatives.We measured AOPP by UV-spectrophotometry and MDA by high performance liquid chromatography .

The main finding in this study is that plasma AOPP and MDA concentration in patients with psoriasis are not different from healthy subjects. Nor could we demonstrate any association between AOPP or MDA and the severity of psoriasis as evaluated by PASI when adjusted for age and gender differences. AOPP and MDA levels were strongly dependent on gender, with higher levels in males both in patients and healthy subjects. Also higher levels of AOPP were associated with higher BMI and hemoglobin levels when adjusted for age and gender. Neither AOPP nor MDA were associated with fatigue.

It is planned to measure cytokine activation and gene expression as the next step and to explore the possible association of these with fatigue in psoriasis patients.