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

Manganese poisoning is well known to result in Parkinsonian symptoms. The present study examined the relation between serum levels of heavy metals and Parkinson's disease in China. Subjects comprised 37 Parkinson's disease patients (22 men, 15 women; mean (±SD) age, 63.3 ±10.9 years) who had been patients for <3 years, and sex- and age-matched controls with no Parkinson's disease, but with headache, dizziness etc. attending the outpatient clinic of Xiangfan No. 1 People's Hospital in Hubei, China. Intake of metals was computed from a nutritional survey by ingestion frequency per week before diagnosis of Parkinson's disease. Morning blood samples were collected before breakfast. Serum was used to measure concentrations of manganese, iron, copper and zinc. Informed consent was obtained from all subjects, and the study protocol was approved by the ethics committee of Fukushima Medical University. Fasting serum levels of manganese, iron, copper and zinc in Parkinson's disease patients were 0.028±0.034 microgram/ml, 1.55±0.97 microgram/ml, 1.03±0.26 microgram/ml and 0.76±0.27 microgram/ml, respectively. Levels in controls were 0.012±0.005 microgram/ml, 0.99±0.68 microgram/ml, 0.99±0.26 microgram/ml and 0.70±0.24 microgram/ml, respectively. Serum manganese and iron levels were significantly higher in Parkinson's disease patients than in controls. No differences were seen in intake of each metal between groups, but water and tea intakes were significantly lower in Parkinson's disease patients. In China, accumulation of manganese and iron in blood might be involved in the etiology of Parkinson's disease.