Assessing Plasma Levels of Selenium, Copper, Iron and Zinc in Patients of Parkinson’s Disease

Abstract

Trace elements have been recognized to play an important role in the development of Parkinson’s disease (PD). However, it is difficult to precisely identify the relationship between these elements and the progression of PD because of an insufficient number of patients. In this study, quantifications of selenium (Se), copper (Cu), iron (Fe) and zinc (Zn) by atomic absorption spectrophotometry were performed in plasma from 238 PD patients and 302 controls recruited from eastern China, which is so far the largest cohort of PD patients and controls for measuring plasma levels of these elements. We found that plasma Se and Fe concentrations were significantly increased whereas Cu and Zn concentrations decreased in PD patients as compared with controls. Meanwhile, these four elements displayed differential changes with regard to age. Linear and logistic regression analyses revealed that both Fe and Zn were negatively correlated with age in PD patients. Association analysis suggests that lower plasma Se and Fe levels may reduce the risk for PD, whereas lower plasma Zn is probably a PD risk factor. Finally, a model was generated to predict PD patients based on the plasma concentrations of these four trace elements as well as other features such as sex and age, which achieved an accuracy of 80.97±1.34% using 10-fold cross-validation. In summary, our data provide new insights into the roles of Se, Cu, Fe and Zn in PD progression.

Wilson's disease and other neurological copper disorders

“…98 However, copper levels are decreased in both the serum and the substantia nigra of PD patients, making direct implication of copper in the pathogenesis of PD unlikely. 99,100 In contrast, iron levels are increased in PD brain tissue. 89 As mentioned above, the copper-containing protein CP has ferroxidase activity and decreased CP levels lead to increased iron deposition in the substantia nigra (SN) in PD and lower CP levels may be associated with earlier onset of this condition.…”

Selenium, selenoproteins and neurodegenerative diseases

“…159 In contrast to Shahar's comments that PD pathology may cause malnutrition and Se deficiency, a large cohort of PD patients and controls from eastern China, (238 PD; 302 controls) reported that plasma Se (and iron) levels were significantly increased in patients with idiopathic PD. 160 Clearly, epidemiological studies with a higher statistical power are required to confirm or deny a possible association between circulating Se and PD. Additionally, it is advisable that several different biological matrices (e.g.…”

Folic acid supplementation rescues anomalies associated with knockdown of parkin in dopaminergic and serotonergic neurons in Drosophila model of Parkinson's disease

“…Moreover, folate involvement in nucleotide metabolism as a cofactor in transfer of 1-carbon unit is well established. Further, Parkinson's disease often involves certain micronutrient deficiency like folic acid [16,17] and zinc (Forsleff et al, 1999;Zhao et al, 2013). Folic acid deficiency in PD is also the cause of hyperhomocysteinemia [17] which in turn is responsible for DNA damage and p53 dependent mitochondrial mediated apoptosis [16].…”