Sociomedical and Life-Style Risk Factors of Senile Dementia, Determined in a Nested Case-Control Study.

Abstract

To explore the sociomedical and life-style risk factors associated with the development of senile dementia, we conducted a nested case-control study with the following subjects: cases were those who underwent health examination for the aged in 1979-1980 in a town in Aichi Prefecture and nineteen cases identified as having senile dementia 13—14 years later. Two controls per case were randomly selected from those who underwent the same health examination and were proven not to have dementia up to 1993, with thirty-eight controls matched to each case for sex, age at first examination (±2 years), and residential area. Routine odds ratio analysis demonstrated the following relationships between onset of senile dementia and sociomedical and life-style factors of 13—14 years ago. (A) factors significantly associated with an increased risk of dementia were (1) difficulty in using fingers (odds ratio—12.1; 95% confidence interval—1.54—94.7), (2) alcoholic beverage drinking habits (6.00; 1.07—33.5), (3) use of false teeth (3.50; 1.10—61.6), (4) less frequent chance to converse (3.85; 1.15—12.5), (5) much spare time (3.70; 1.43—25.0), (6) decrease of number of friends (2.77; 1.12—11.1), and (7) inability to calculate subtractions such as 29—17 (3.33—33.3). On the contrary, (B) habitual physical activities significantly reduced the risk of developing senile dementia (0.27; 0.05—0.71). (C) cigarette smokers and regular users of sleeping pills were not at greater risk of subsequent senile dementia, to which such personal characteristics as shyness and nervousness were not significantly linked. © 1994, The Japan Geriatrics Society. All rights reserved.