A case-control study was conducted in Italy to evaluate the possible association between exposure to extremely low-frequency magnetic fields generated by high-voltage overhead power lines and Alzheimer's disease and Parkinson's disease.
To test the validity of the study design, a further group of cases and controls has been introduced to study the association between exposure to extremely low-frequency magnetic fields and diabetes mellitus, for which there is currently no evidence in the literature.
|Group 1||distance between residence and power line: < 50 m|
|Group 2||distance between residence and power line: 50 - 199 m|
|Group 3||distance between residence and power line: 200 - 599 m|
|Reference group 4||distance between residence and power line: ≥ 600 m|
Statistically non-significant slightly increased risks were observed for Alzheimer's disease (OR 1.11, CI 0.95-1.30) or for Parkinson’s disease (OR 1.09, CI 0.92–1.30) in residents living < 50 m to high voltage power lines compared to residents at a distance ≥ 600 m.
The overlap of the results obtained in relation to diabetes mellitus compared with those already reported in the literature (no association with exposure to extremely low-frequency magnetic fields and strong association with socio-economic deprivation) confirms the overall soundness of the study design used.
The authors conclude that the finding of a weak association between exposure to extremely low-frequency magnetic fields and neurodegenerative diseases suggests the continuation of research on this topic. Moreover, the low consistency between the results of the already existing studies emphasizes the importance of increasingly refined study designs.