Hair Microelement Profile as a Prognostic Tool in Parkinson's Disease

Changes in the homeostasis of metals and microelements have been demonstrated in Parkinson's disease, whose etiology includes both a genetic and environmental basis. We studied the difference of microelements in the hair of Parkinson's disease subjects (n = 46) compared with healthy controls (n = 24). Hair was chosen as a representative matrix to measure microelements, since it is a vehicle of substance excretion from the human body and it allows for long-term evaluation of metal exposure. An inductively coupled plasma mass spectrometry (ICP-MS) analysis of hair collected from 24 Parkinson's patients compared with their healthy relatives used as controls shows a significant decrease in Ca (U = 166, p = 0.012),), Mg (U = 187, p = 0.037), and Sr (U = 183, p = 0.030). Cd and Ca/Mg were decreased, and Cu was increased, in patients with respect to their healthy related controls at the limit of significance (p = 0.0501). Principal Component Analysis (PCA) of these microelements in hair shows a clustering into two groups according to gender, disease severity according to the Hoehn-Yahr scale, and pharmacological therapy. This pilot study represents a starting point for future investigations where a larger group of subjects will be involved to define other microelements useful when screening for early biomarkers of Parkinson's disease.