Smoking cessation, lung function, and weight gain: a follow-up study.
BACKGROUND
Only one population-based study in one country has reported effects of smoking cessation and weight change on lung function, and none has reported the net effect. We estimated the net benefit of smoking cessation, and the independent effects of smoking and weight change on change in ventilatory lung function in the international European Community Respiratory Health Survey.


METHODS
6654 participants in 27 centres had lung function measured in 1991-93, when aged 20-44 years, and in 1998-2002. Smoking information was obtained from detailed questionnaires. Changes in lung function were analysed by change in smoking and weight, adjusted for age and height, in men and women separately and together with interaction terms.


RESULTS
Compared with those who had never smoked, decline in FEV1 was lower in male sustained quitters (mean difference 5.4 mL per year, 95% CI 1.7 to 9.1) and those who quit between surveys (2.5 mL, -1.9 to 7.0), and greater in smokers (-4.8 mL, -7.9 to -1.6). In women, estimates were 1.3 mL per year (-1.5 to 4.1), 2.8 mL (-0.8 to 6.3) and -5.1 mL (-7.5 to -2.8), respectively. These sex differences were not significant. FEV1 changed by -11.5 mL (-13.3 to -9.6) per kg weight gained in men, and by -3.7 mL per kg (-5.0 to -2.5) in women, which diminished the benefit of quitting by 38% in men, and by 17% in women.


CONCLUSIONS
Smoking cessation is beneficial for lung function, but maximum benefit needs control of weight gain, especially in men.
Chinn
Susan
S
Department of Public Health Sciences, King's College London, 5th Floor Capital House, 42 Weston Street, London SE1 3QD, UK. sue.chinn@kcl.ac.uk
Jarvis
Deborah
D
Melotti
Roberto
R
Luczynska
Christina
C
Ackermann-Liebrich
Ursula
U
Antó
Josep M
JM
Cerveri
Isa
I
de Marco
Roberto
R
Gislason
Thorarinn
T
Heinrich
Joachim
J
Janson
Christer
C
Künzli
Nino
N
Leynaert
Bénédicte
B
Neukirch
Françoise
F
Schouten
Jan
J
Sunyer
Jordi
J
Svanes
Cecilie
C
Vermeire
Paul
P
Wjst
Matthias
M
Burney
Peter
P
D000328:Adult; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D012907:Smoking / Q000503:physiopathology; D016540:Smoking Cessation; D013147:Spirometry; D014797:Vital Capacity; D015430:Weight Gain