[A case-control study on the influencing factors to mild cognitive impairment among the community-based elderly population].

OBJECTIVE To explore the influencing factors on mild cognitive impairment among the community-based elderly population. METHODS A 'n : m' matched case-control study was conducted to analyze the risk factors. Cox regression model of survival analysis was selected to deal with non-geometric proportional matched data which was difficult to analyze by logistic regression model. RESULTS Four hundred and twenty-three cases together with nine hundred and twenty-five controls were interviewed with an uniformed questionnaire. Through univariate and multivariate cox regression analysis, the odds ratio and 95% CI of these risk factors appeared to be: physical labor as 1.396 (1.092-1.785); smoking as 1.551 (1.021-2.359); higher level of blood glucose as 1.354 (1.102-1.664); HDL-C in the serum as 1.543 (1.232-1.932); LDL-C in the serum as 1.299 (1.060-1.592); lower level of estrogen in the serum as 1.263 (1.031-1.547); hypertension as 1.967 (1.438-2.689); diabete: 1.381 (1.139-1.675); depressive disorder: 1.406 (1.110-1.780); cerebral thrombosis as 1.593 (1.307-1.943); higher SBP as 1.331 (1.129-1.569) and ApoEepsilon 4 carrier as 1.462 (1.140-1.873) respectively. Odds ratio and 95% CI on protection factors appeared to be: reading newspaper frequently as 0.610 (0.503-0.740); frequently doing housework as 0.804 (0.665-0.973); frequently engaging in social activities as 0.617 (0.502-0.757); reemployment after formal retirement as 0.759 (0.636-0.906); having acumen olfaction as 0.900 (0.845-0.958); having extrovert personality as 0.829 (0.699-0.984); being decisive as 0.811 (0.662-0.993). CONCLUSION The major measures to prevent MCI seemed to be including the following factors as: being intellectuals, engaging in healthy life style and decreasing the risk in developing hypertension, diabetes, depressive disorder and cerebrovascular disease. However, olfactory hypoesthesia, cowardice and having introvert character, ApoEepsilon 4 carrier etc could be treated as early indications to signify MCI.