Organochlorine pesticide levels and risk of Alzheimer's disease in north Indian population.

Alzheimer's disease (AD) could result from a multifactorial process involving both genetic predisposition and exposure to environmental factors like pesticides. A case control study of 70 patients of AD and 75 controls was done to examine the association between organochlorine pesticides (OCPs) and risk of AD. OCPs (hexachlorocyclohexane (HCH), aldrin, dieldrin, endosulfan, pp'-dichlorodiphenyldichloroethylene (pp'-DDE), op'-DDE, pp'-dichlorodiphenyltrichloroethane (pp'-DDT), op'-DDT, pp'-dichlorodiphenyldichloroethane (pp'-DDD) and op'-DDD) were extracted from blood and quantitatively estimated using gas chromatography. A Mann-Whitney U test revealed significant difference in β-HCH levels (U = 1237.00, W = 4087.00, z = -6.296, p = 0.000, r = -0.71), dieldrin levels (U = 1449.00, W = 4299.00, z = -5.809, p = 0.000, r = -0.68) and pp'-DDE levels (U = 2062.00, W = 4912.00, z = -2.698, p = 0.007, r = -0.59) between AD patients and controls. In conclusion, this study supports epidemiological studies that associate exposure to pesticides with increased risk of AD, and we identified the specific pesticides β-HCH, dieldrin and pp'-DDE that are associated with the risk of AD in the north Indian population. However, further research is needed to establish the potential role of these OCPs as an etiologic agent for AD case.