Trace Metals in Patients with Parkinson’s Disease: A Multi-Center Case-Control Study of Nigerian Patients

Abstract

Background: The roles of environmental factors in the etiologic consideration of Parkinson’s disease (PD) need investigation and clarification, especially in sub-Saharan Africa where genetic mutations are rare. Trace metals toxicity has been associated with pathogenesis of neuro-degeneration including Parkinson’s disease. 

Methods: PD patients presenting to three tertiary health facilities located in the south-west, south-south and central Nigeria were studied and compared with age and sex matched controls from the same regions using a protocol containing a structured questionnaire, diagnostic criteria based on the United Kingdom Parkinson’s Disease Society brain bank and atomic absorption spectrophotometry method for analysis of plasma trace metals – copper, zinc, magnesium, manganese and iron. 

Findings: Sixty eight consecutive PD patients with a mean age of 65.7±7.29 years and a male preponderance (Male (46)/Female (22) = 2.1:1) had significantly elevated trace metals (namely copper, zinc, magnesium and iron) compared to controls (P<0.001). The means of the trace metals’ levels for the PD and controls were – Copper 51.8 and 14.7µmol/l, Magnesium 3.35 and 2.06mEq/l, Manganese 15.6 and 14.4µmol/l, Iron 78.5 and 17.4µmol/l and Zinc 88.7 and 19.3µmol/l respectively. There was no significant difference in level of manganese between PD patients and controls, though elevated in PD patients residing in the southern part of the country the difference between the PD patients and controls in central region (P=0.29) was insignificant. 

Conclusion: The findings of this study suggested a possible role for trace metals toxicity in the pathogenesis of Parkinson’s disease. There is however need for further studies to elucidate the specific roles of these trace metals in the etiology of PD.