BACKGROUND: We examined the association between extremely low-frequency magnetic fields (EMF) and the risk of dementia and Alzheimer's disease using all 9,508 individuals from the Study of Dementia in Swedish Twins (HARMONY) with valid occupational and diagnostic data. METHODS: Dementia diagnoses were based on telephone screening followed by in-person clinical workup. Main lifetime occupation was coded according to an established EMF exposure matrix. Covariates were age, gender, education, vascular risk factors, and complexity of work. Based on previous research, data were also analyzed separately for cases with disease onset by age 75 years versus later, men versus women, and those with manual versus nonmanual main occupation. We used generalized estimating equations with the entire sample (to adjust for the inclusion of complete twin pairs) and conditional logistic regression with complete twin pairs only. RESULTS: Level of EMF exposure was not significantly associated with dementia or Alzheimer's disease. However, in stratified analyses, medium and high levels of EMF exposure were associated with increased dementia risk compared with low level in cases with onset by age 75 years (odds ratio: 1.94, 95% confidence interval: 1.07-3.65 for medium, odds ratio: 2.01, 95% confidence interval: 1.10-3.65 for high) and in participants with manual occupations (odds ratio: 1.81, 95% confidence interval: 1.06-3.09 for medium, odds ratio: 1.75, 95% confidence interval: 1.00-3.05 for high). Results with 42 twin pairs discordant for dementia did not reach statistical significance. CONCLUSIONS: Occupational EMF exposure appears relevant primarily to dementia with an earlier onset and among former manual workers.
BACKGROUND: We examined the association between extremely low-frequency magnetic fields (EMF) and the risk of dementia and Alzheimer's disease using all 9,508 individuals from the Study of Dementia in Swedish Twins (HARMONY) with valid occupational and diagnostic data. METHODS:Dementia diagnoses were based on telephone screening followed by in-person clinical workup. Main lifetime occupation was coded according to an established EMF exposure matrix. Covariates were age, gender, education, vascular risk factors, and complexity of work. Based on previous research, data were also analyzed separately for cases with disease onset by age 75 years versus later, men versus women, and those with manual versus nonmanual main occupation. We used generalized estimating equations with the entire sample (to adjust for the inclusion of complete twin pairs) and conditional logistic regression with complete twin pairs only. RESULTS: Level of EMF exposure was not significantly associated with dementia or Alzheimer's disease. However, in stratified analyses, medium and high levels of EMF exposure were associated with increased dementia risk compared with low level in cases with onset by age 75 years (odds ratio: 1.94, 95% confidence interval: 1.07-3.65 for medium, odds ratio: 2.01, 95% confidence interval: 1.10-3.65 for high) and in participants with manual occupations (odds ratio: 1.81, 95% confidence interval: 1.06-3.09 for medium, odds ratio: 1.75, 95% confidence interval: 1.00-3.05 for high). Results with 42 twin pairs discordant for dementia did not reach statistical significance. CONCLUSIONS: Occupational EMF exposure appears relevant primarily to dementia with an earlier onset and among former manual workers.
Authors: Margaret Gatz; Chandra A Reynolds; Richard John; Boo Johansson; James A Mortimer; Nancy L Pedersen Journal: Int Psychogeriatr Date: 2002-09 Impact factor: 3.878
Authors: Andreas Seidler; Petra Geller; Albert Nienhaus; Tanja Bernhardt; Ingeburg Ruppe; Siegfried Eggert; Maila Hietanen; Timo Kauppinen; Lutz Frölich Journal: Occup Environ Med Date: 2006-10-16 Impact factor: 4.402
Authors: Margaret Gatz; Laura Fratiglioni; Boo Johansson; Stig Berg; James A Mortimer; Chandra A Reynolds; Amy Fiske; Nancy L Pedersen Journal: Neurobiol Aging Date: 2005-04 Impact factor: 4.673
Authors: Ross Andel; Michael Crowe; Nancy L Pedersen; James Mortimer; Eileen Crimmins; Boo Johansson; Margaret Gatz Journal: J Gerontol B Psychol Sci Soc Sci Date: 2005-09 Impact factor: 4.077
Authors: G C Román; T K Tatemichi; T Erkinjuntti; J L Cummings; J C Masdeu; J H Garcia; L Amaducci; J M Orgogozo; A Brun; A Hofman Journal: Neurology Date: 1993-02 Impact factor: 9.910