Risk factors for Alzheimer's disease in Russia: a case-control study.

No reliable data on risk factors of Alzheimer's disease (AD) are available in Russia. We aimed to evaluate the relative importance of various putative environmental and medical risk factors of AD in a Russian population. We conducted a hospital-based case-control study. Two hundred and sixty consecutive AD patients and an equal number of cognitive impairment-free control subjects matched for sex, age, level of education and place of birth selected from nursing homes and other long-term healthcare facilities in the Novosibirsk region for the period from 1998 to 2002 were examined. A conditional logistic regression analysis was employed to calculate odds ratios (OR) and corresponding 95% confidence intervals (CI) for various putative risk factors. Of the 260 patients with AD, 187 (72%) were females. Patients' age varied from 40 to 89 years (mean +/- SD: 69.2 +/- 7.7 years). The majority of the patients (77%) had secondary education and 12% had university education. Risk factors independently associated with AD were family history of parkinsonism among first-degree relatives (OR = 4.2; 95% CI 1.2-15.1), hypothyroidism (OR = 2.7; 95% CI 1.1-6.7), and history of head trauma with loss of consciousness (OR = 1.7; 95% CI 1.0-2.8). The most important risk factors for AD in the Russian community are family history of parkinsonism, hypothyroidism and a history of head trauma with loss of consciousness. These findings have implications for developing preventive strategies of AD.