Smoking status and its relationship with exercise capacity, physical activity in daily life and quality of life in physically independent, elderly individuals

Abstract

Objective: To investigate the relationship between smoking status and exercise capacity, physical activity in daily life and health-related quality of life in physically independent, elderly (≥60 years) individuals.

Design: Cross-sectional, observational study.

Setting: Community-dwelling, elderly individuals.

Participants: One hundred and fifty-four elderly individuals were categorised into four groups according to their smoking status: never smokers (n=57), passive smokers (n=30), ex-smokers (n=45) and current smokers (n=22).

Main outcome measures: Exercise capacity [6-minute walk test (6MWT)], physical activity in daily life (step counting) and health-related quality of life [36-Item Short Form Health Survey (SF-36) questionnaire] were assessed.

Results: Current and ex-smokers had lower mean exercise capacity compared with never smokers: 90 [standard deviation (SD) 10] % predicted, 91 (SD 12) % predicted and 100 (SD 13) % predicted distance on 6MWT, respectively [mean differences -9.8%, 95% confidence intervals (CI) -17.8 to -1.8 and -9.1%, 95% CI -15.4 to -2.7, respectively; P<0.05 for both]. The level of physical activity did not differ between the groups, but was found to correlate negatively with the level of nicotine dependence in current smokers (r=-0.47, P=0.03). The median score for the mental health dimension of SF-36 was worse in passive {72 [interquartile range (IQR) 56 to 96] points} and current [76 (IQR 55 to 80) points] smokers compared with ex-smokers [88 (IQR 70 to 100) points] (median differences -16 points, 95% CI -22.2 to -3.0 and -12 points, 95% CI -22.8 to -2.4, respectively; P<0.05 for both).

Conclusions: Among elderly individuals, current smokers had lower exercise capacity than never smokers. Although the level of physical activity did not differ between the groups, an association was found with smoking. Tobacco exposure was associated with worse scores for the mental health dimension of SF-36 in physically independent, elderly individuals.

Keywords: Aged; Exercise tolerance; Physical activity; Quality of life; Smoking.