Evaluation of dose-response relationship between smoking load and cardiopulmonary fitness in adult smokers: A cross-sectional study.
OBJECTIVE
To evaluate the dose-response relationship between smoking load and cardiopulmonary fitness, as measured with cardiopulmonary exercise testing (CPET), in adult smokers free of respiratory diseases.


METHODS
After a complete clinical evaluation and spirometry, 95 adult smokers (35 men and 60 women) underwent CPET on a treadmill.


RESULTS
The physiological responses during CPET showed lower cardiorespiratory fitness levels, regardless of smoking load, with a peak [Formula: see text] lower than 100% of the expected value and a lower maximum heart rate. We observed a significant moderate negative correlation between smoking load and peak [Formula: see text] . The smoking load also presented a significant negative correlation with maximum heart rate(r=-0.36; p<0.05), lactate threshold(r=-0.45; p<0.05), and peak ventilation(r=-0.43; p<0.05). However, a dose-response relationship between smoking load quartiles and cardiopulmonary fitness was not found comparing quartiles of smoking loads after adjustment for age, sex and cardiovascular risk.


CONCLUSIONS
There appears to be no dose-response relationship between SL and cardiopulmonary fitness in adult smokers with preserved pulmonary function, after adjusting the analysis for age and cardiovascular risk. Our results suggest that smoking cessation might be useful as the primary strategy to prevent cardiopulmonary fitness decline in smokers, regardless of smoking load. Thus, even a very low dose of tobacco use must be avoided in preventive strategies focusing on becoming people more physically active and fit.
Laboratory of Epidemiology and Human Movement (EPIMOV), Federal University of São Paulo, Santos, Brazil. Electronic address: viniciuslauria@hotmail.com.
V T
VT
Lauria
Laboratory of Epidemiology and Human Movement (EPIMOV), Federal University of São Paulo, Santos, Brazil.
E F
EF
Sperandio
Laboratory of Epidemiology and Human Movement (EPIMOV), Federal University of São Paulo, Santos, Brazil.
T L W
TL
de Sousa
Laboratory of Epidemiology and Human Movement (EPIMOV), Federal University of São Paulo, Santos, Brazil.
W
W
de Oliveira Vieira
Angiocorpore Institute of Cardiovascular Medicine, Santos, Brazil.
M
M
Romiti
Angiocorpore Institute of Cardiovascular Medicine, Santos, Brazil.
A R
AR
de Toledo Gagliardi
Angiocorpore Institute of Cardiovascular Medicine, Santos, Brazil.
R L
RL
Arantes
Laboratory of Epidemiology and Human Movement (EPIMOV), Federal University of São Paulo, Santos, Brazil.
V Z
VZ
Dourado
D000328:Adult; D000072599:Cardiorespiratory Fitness; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012906:Smoke; D012907:Smoking / Q000503:physiopathology*; D014026:Nicotiana
D012906:Smoke
Cardiopulmonary exercise testing; Physical fitness; Smoking load; Spirometry; Tobacco use disorder