Selenium and Arsenic Levels, Prevalence of Common Variants of Genes Involved in Their Metabolism, and Psoriasis Disease

Using an Inductively Coupled Plasma Mass Spectrometer we measured the concentration of selenium and arsenic in serum and blood samples from 336 unselected psoriatic patients and 336 matched healthy controls to evaluate any associations with the clinical course of the disease. We genotyped 336 patients and 903 matched controls to evaluate the prevalence of <i>SOD2</i> (rs4880), <i>CAT</i> (rs1001179), <i>GPX1</i> (rs1050450), and <i>DMGDH</i> (rs921943) polymorphisms using Taqman assays. The mean selenium (Se) level in serum was 74 µg/L in patients and 86 µg/L in controls (<i>p</i> < 0.001). The mean Se level in blood was 95 µg/L in patients and 111 µg/L in controls (<i>p</i> < 0.001). Psoriasis risk was greatest among participants with the lowest serum (<68.75 µg/L, OR: 8.30; <i>p</i> < 0.001) and lowest blood concentrations of Se (<88.04 µg/L, OR: 10.3; <i>p</i> < 0.001). Similar results were observed in subgroups of males and females. We found an inverse correlation of selenium levels with PASI, NAPSI, and BSA scores. There was no significant difference in the distribution of the <i>CAT</i>, <i>GPX1</i>, <i>DMGDH</i>, and <i>SOD2</i> polymorphisms. Among carriers of rs4880, rs1001179, and rs921943 polymorphisms, blood selenium levels were significantly lower. The mean arsenic level in serum was 0.79 µg/L in patients and 0.7 µg/L in controls (<i>p</i> = 0.2). The mean concentration in blood was 1.1 µg/L in patients and 1.3 µg/L in controls (<i>p</i> < 0.001). In conclusion, we found that lower selenium levels, in blood and serum, are associated with psoriasis risk and its more severe course. Future prospective studies should focus on the optimalisation of the concentration of this trace element not only for prophylactic guidance but also to support the treatment of this disease.