Purpose: In the present study, we observed the association of cognitive impairment with current/former habits of smoking, alcohol consumption, tea consumption, and exercise among very old people using a Chinese cohort aged 90 to 108 years.
Methods: A cross-sectional study.
Results: The sample included 681 unrelated Chinese nonagenarians/centenarians (67.25% women). In men, compared with subjects without cognitive impairment, those with cognitive impairment had significantly higher prevalence of habits of smoking (P=0.048 and 0.004, for former/current, respectively) and alcohol consumption (P=0.003 and 0.049, for former/current, respectively) but had significantly lower prevalence of habits of tea consumption (P=0.041 and 0.044, for former/current, respectively) and current exercise (P=0.020). Subjects with habits of smoking had significantly lower cognitive function scores than those without these habits (mean difference=1.78 and 1.69, P=0.029 and 0.035, for former/current, respectively), but subjects with habit of current exercise had significantly higher cognitive function scores than those without this habit (mean difference=1.53, P=0.038). However, in women, there were no significant differences in prevalence of these habits between subjects with and without cognitive impairment and also no significant differences in cognitive function scores between subjects with and without these habits. Only current smoking habits in men had a significant odds ratio for cognitive impairment (odds ratio, 2.125; 95% confidence interval, 1.186-3.998).
Conclusions: Among nonagenarians/centenarians, in men, there are associations of cognitive impairment with habits of former/current smoking and current exercise, as well as indefinite associations with habits of alcohol and tea consumption. Smoking may have a significant negative impact on cognitive function, but current exercise significantly improve cognitive function. However, in women, there are no associations of cognitive impairment with all the habits.