Serum trace element levels and the complexity of inter-element relations in patients with Parkinson's disease

Trace elements have been postulated to play a role in Parkinson's disease (PD). In order to elucidate whether changes in the serum levels of trace elements reflect the progression of PD, we assessed serum levels of 12 elements (Na, K, Fe, Al, Cu, Zn, Ca, Mg, Mn, Si, P and S) in early PD, severe PD and normal subjects, using inductively coupled plasma atomic emission spectrometry. The concentrations in micromol/ml, the relative mole percentage distribution and inter-element relations were computed. Statistical analysis of these data showed a definite pattern of variation among certain elements in early and severe PD compared to controls. In both early and severe PD serum, Al and S concentrations were significantly decreased (p<0.05) compared to the controls. Fe (p<0.01) and Zn (p<0.05) concentrations were significantly lower in severe PD, while K, Mg, Cu (p < 0.01) and P (p < 0.05) concentrations were higher in early and severe PD compared to the controls. The data revealed an imbalance in the inter-element relations in both early and severe PD serum compared to controls, as shown by the direct and inverse correlations. These results suggest a disturbance in the element homeostasis during the progression of PD.