Rui-lian Ding,1,* Cheng Fu,2,3,* Yu Zheng,1 Jin Bu,1 Er-Xia Shen2 

1Hospital for Skin Disease (Institute of Dermatology), Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, Jiangsu, People’s Republic of China; 2Sino-French Hoffmann Institute, School of Basic Medical Sciences; The Second Affiliated Hospital of Guangzhou Medical University, State Key Laboratory of Respiratory Disease, Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, Guangzhou Medical University, Guangzhou, Guangdong, People’s Republic of China; 3Shenzhen Children’s Hospital, Shenzhen, Guangdong, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Jin Bu; Er-Xia Shen, Email dr.jinbu@gmail.com; erxia_shen@gzhmu.edu.cn

Objective: Psoriasis is a common chronic inflammatory disease. However, trace elements are essential to biochemical processes of the skin, it is suspected that the trace elements are vital in the pathogenesis of psoriasis. Our research is aimed to investigate the association between serum levels and dietary intake levels of selenium, zinc, and copper with psoriasis.
Methods: In this cross-sectional study, we utilized the National Health and Nutrition Examination Survey data from 2011 to 2014 to examine the association between psoriasis and serum concentration and dietary intake of trace elements including copper, zinc, and selenium in the US individuals. Our research combined two cycles and weighted the data. Student’s t-tests and χ 2 test were used. Subgroup analyses and interaction tests were conducted by IBM SPSS Statistics 22 and EmpowerStats.
Results: This study indicates that the population with psoriasis has a lower dose of dietary intake selenium than the controls, and risk analysis showed that the men with selenium daily intake > 150 mcg/day have a decreasing risk for psoriasis compared to those with daily intaking selenium < 75 mcg/day. However, there are no differences on daily intake of selenium, zinc, and copper and serum levels of Zinc and Copper between psoriasis and healthy controls. The current study showed that the psoriasis group was significantly older with a bigger waist circumference, a higher education level, a higher ratio of people with smoke every day, and a higher ratio of people in USA and being non-Hispanic White.
Conclusion: This cross-section study showed that a high selenium intake may benefit USA adults from psoriasis, especially for males. The social and cultural background and ethnic differences between the two groups influence the eating and living models, including the trace element intake. The national recommended dietary allowances (RDAs) might be considered to be modified with more reliable investigative clinical data and certain considering the social and cultural models.

Keywords: trace elements, selenium, zinc, copper, serum level, dietary intake