OBJECTIVETo investigate the risk of Alzheimer's disease (AD) associated with life style, early exposure to magnetic fields, family history of dementia and other risk factors.

METHODSWe conducted a case-control study among the inpatients of Chinese PLA General Hospital in 2000 - 2003. Sixty-two AD cases and 124 controls were selected and matched for age. Univariate and multivariate analyses were conducted using logistic regression model.

RESULTSAll subjects were males aged 66 to 102. In univariate analysis, lack of social activities, more physical exercises, early exposure to magnetic fields, suffering from negative life events and family history of dementia were statistically different between two groups (P < 0.05). Multivariate analysis showed that after adjusting for potential confounders, suffering from negative life events, family histories of dementia increased the risk of AD with odds ratio (OR) and 95% confidence interval (CI) 3.27 (1.53 - 6.97) and 5.78 (1.39 - 24.10). Early exposure to magnetic fields seemed a possible risk factor for AD, with OR (95% CI) 2.49 (0.96 - 6.45). The amount of social activities, cigarette smoking and history of cancers were negatively correlated with AD and their ORs (95% CI) were 0.81 (0.72 - 0.92), 0.46 (0.21 - 1.00) and 0.31 (0.12 - 0.82) respectively.

CONCLUSIONThe study demonstrated that suffering from negative life events and family history of dementia were risk factors for AD, and the early exposure to magnetic fields might also play a role.