Relationship between blood levels of heavy metals and Parkinson's disease in China

Background: Idiopathic Parkinson's disease (PD) and the Parkinsonian syndrome caused by manganese (Mn) poisoning are known to be indistinguishable in terms of symptoms. We thus suspect that many patients who have accumulated Mn in the body in daily life are diagnosed as having idiopathic PD. We examined the relationship between PD and blood levels of heavy metals, and the influence of intake from food in a general population. Methods: The subjects comprised PD patients and sex- and age-matched controls recruited from the outpatient clinic of Xiangfan No. 1 People's Hospital in Hubei, China, between 2006 and 2008. Information was obtained on previous eating habits before diagnosis of PD and other factors. Morning blood samples were collected before breakfast and were used to measure concentrations of metals. Results: The whole-blood Mn and serum iron (Fe) levels were significantly higher in PD patients than in controls. However, no differences in intake of each metal from food or experience of Mn poisoning were seen between the groups. Conclusions: In China, accumulation of Mn and Fe via unknown routes might be involved in the etiology of PD in the general population.