Impact of smoking on mortality in 80-year-old Japanese from the general population

Background: It is well known that cigarette smoking is the main health hazard in middle-aged people.However, data regarding smoking and health in old-aged people are limited, especially in the Japanese population. Objective: The present study aimed to investigate the influence of smoking on mortality in the elderly Japanese population. Methods: A cohort of 690 individuals of 80 years of age were categorized into 3 groups: non-smokers, ex-smokers and current smokers. The adjusted mortality after 4 years was compared among the 3 groups. The possible influence of smoking status on the cause of death was also investigated. Results: The overall mortality was significantly higher in males [relative risk (RR): 2.3, 95% confidence interval (CI): 1.0-5.2] and females (RR: 4.2, 95% CI: 1.9-9.5) in the current-smoker group than in the non-smoker group. The risk of any-cause mortality in the ex-smoker group was not statistically different from that in the non-smoker group. In males, current smokers died of cancer more frequently than non-smokers (RR: 10.7, 95% CI: 1.3-90.8). Cardiovascular disease was a significant cause of death in female current smokers (RR: 5.2, 95% CI: 1.6-16.9). This difference in mortality was not observed between groups of non-smokers and ex-smokers of both genders. In male smokers, there was a positive relationship between the daily amount of consumed cigarettes and overall mortality. Conclusion: Smokers should be encouraged to stop smoking, since habitual smoking increases the risk of mortality even in old age.