The cumulative effect of smoking at age 50, 60, and 70 on functional ability at age 75

Abstract

Aims: As elderly people form a steadily growing part of the population in most parts of the world we are in need of knowledge of the influence of modifiable lifestyle factors on functional ability late in life. This study aims to examine the cumulative impact of smoking from age 50 to 70 on functional ability at age 75. Methods: 387 men and women born in 1914 and living in seven municipalities in the western part of the County of Copenhagen were followed for 25 years with examinations in 1964, 1974, 1984, and 1989. Associations between smoking and functional ability were examined using multiple logistic regression analyses with cumulative smoking as determinant and physical activity, sex, basic school education, and household composition as possible confounders. Results: There is an adverse relation between smoking and functional ability regardless of the time of examination or the ways of accumulating the smoking habits over the examinations. Cumulated former smokers have a larger risk of having reduced functional ability at age 75 (OR: 1.35 (1.13 - 1.61)) compared with never smokers. The odds ratios of reduced functional ability were 2.46 (1.44 - 4.17) among cumulated smokers of 1 - 14 grams of tobacco/day and 3.32 (1.63 - 6.72) among smokers of more than 14 grams of tobacco/ day. Conclusions: The findings in this study stress the importance of continuing and strengthening efforts to reduce the prevalence of smokers in the population. Furthermore the results indicate that even after the 50th birthday it is possible to gain a healthier old age by abstaining from smoking.