Time to first cigarette, physical activity, and pulmonary function in middle-aged to older adult smokers

Background: How addiction severity relates to physical activity (PA), and if PA moderates the relation between PA and lung function among smokers, is unknown. This study explored the independent and interactive associations of nicotine addiction severity and PA with lung function. Methods: The study used cross-sectional data from 343 adult smokers aged 40 to 79 participating in the 2009-10 and 2011-12 National Health and Nutrition Examination Survey. Assessed were the independent relations of nicotine addiction severity, as measured by the time to first cigarette (TTFC), and average daily minutes of moderate and vigorous PA with lung function ratio (FEV1/FVC). Additional analysis examined whether PA moderated the relationship between addiction severity and lung function. Results: Greater lung function was independently associated with moderate PA and later TTFC, but not vigorous PA, when controlling for cigarettes per day (CPD), past month smoking, ethnicity, years smoked, and gender (P-values < .05). PA did not moderate the association between addiction severity (TTFC) and lung function (P = .441). Conclusion: Among middle-aged to older smokers, increased PA and lower addiction severity were associated with greater lung function, independent of CPD. This may inform research into the protective role of PA and identification of risk factors for interventions.