Three-Month Smoking Cessation Program Linked to Improved Pulmonary Function

Metrics of pulmonary function were associated with significant improvement among smokers who successfully underwent a three-month, multifaceted cessation program, according to a new Japan-based prospective assessment.

While the long-term risks of tobacco smoke on pulmonary disease and lung cancer development have been long documented, less has been made of the short-term value of smoking cessation—in terms of proxies including forced vital capacity (FVC), forced expiratory volume over 1 second (FEV1), and peak expiratory flow.

To understand what a combination of pharmacologic and cognitive-behavioral therapeutic measures would have on such outcomes in smokers, a team of investigators from the Kobe City Medical Center West Hospital in Japan assessed data from such a program in their country.

The data was planned for presentation at the American Thoracic Society (ATS) 2020 International Conference this year.

Investigators defined nicotine dependence by a score of ≥5 points on the Tobacco Dependence Screener test, and tobacco quitters if they had quit completely between an eight-week and 12-week physician visit, with verification from an exhaled carbon monoxide (CO) level of ≤10 ppm.

The team assessed for pulmonary function metrics at baseline and at the end of the cessation program.

Assessment included 876 smokers with nicotine dependence treated in the program from August 2007-March 2019. Of this population, 464 participants completed the program, and had available pulmonary function tests collected at baseline and at program’s end.

Just 34% (n = 159) of observed, completed participants were female; mean age was 62±12 years old; mean baseline exhaled CO level was 15.2±9.9 ppm; and mean FEV1 (20% predicted) was 75.7.

Underlying diseases or past history largely included mental disorders (28.9%); chronic obstructive pulmonary disease (COPD; 23.9%); bronchial asthma (15.3%); diabetes mellitus (18.3%); hypertension (22.2%); cardiovascular disease (19.8%); and cancer (11.6%).

Investigators observed a 0.056±0.372 change in FVC (P = .001); a 0.048±0.273 change in FEV1 (P = .0002); a 0.028±0.495 change in maximal mid-expiratory flow (P = .295); and a 0.344±1.125 change in peak expiratory flow (P <.0001).

“With regard to these changes in pulmonary function, there were no significant differences between quitters (n=308) and continuous smokers (n=156),” they wrote. “In 161 participants (34.7%), FEV1 increased more than 100mL.”

But when investigators compared baseline characteristics of participants presenting with ≥100mL increase in FEV1 and those who did not, they found significant differences in frequency of underlying disease including COPD (34.5% vs 20.5%; P = .018) and bronchial asthma (23.0% vs 11.2%; P = .001). The two groups also difference significantly in baseline FEV1 (1.83±0.74 L vs 2.21±0.75 L, P <.0001).

In their multivariate analysis, bronchial asthma (OR, 2.19; 95% CI, 1.27-3.77) and baseline FEV1 (OR, 0.56; 95% CI, 0.41-0.77) were significantly associated with an FEV1 increase of ≥100mL.

“In our smoking cessation program, significant changes in pulmonary function such as FVC, FEV1, and peak expiratory flow were found,” investigators concluded.

The study, “Changes in Pulmonary Function Before and After the Smoking Cessation Therapy,” was published online by ATS.