KUMJ | VOL. 9 | NO. 3 | ISSUE 35 | JUL-SEP, 2011

Peripheral Airway Responsiveness to Sub-maximal Exercise in Asymptomatic Cigarette Smokers.
Pokhrel BR, Chatopadhyaya S, Paudel BH

Background

Cigarette smoking is one of the cardinal causes for the development of bronchial

hyperresponsiveness among the smokers.

Objectives

This study was perspectively designed to determine the peripheral bronchial

responsiveness to sub-maximal exercise challenge in the asymptomatic smokers.

Methods

The subjects were between age of 18-25 years without any findings of cardiorespiratory

diseases. We performed the 5 min step test exercise at intensity of 80 to

90% of maximum predicted heart rate in 42 young adult male asymptomatic smokers

to examine the effect of cigarette smoking on airway responsiveness. Forced expiratory

spirogram was recorded before and at 0, 5, 10, 15 min after the completion of exercise.

Pre- to post exercise drop in Forced Expiratory Volume in first second ≥ 15% was

considered hyperresponsive to the challenge.

Result

The analysis of data (mean± SE) indicated the bronchial hyper-responsiveness in

22 (52%) smokers. The post exercise recovery time pattern showed drop in forced

expiratory spirogram from the resting baseline in the responsive smokers and the

maximum percentage fall in the parameters or increase in airway resistance which

reflect the peripheral airway integrity such as Forced Expiratory Flow 25% (20.30

±2.18 Vs 7.88 ±3.23, p<0.01), Forced Expiratory Flow 50% (18.46 ±4.40 Vs 1.93 ±2.78,

p<0.01), Forced Expiratory Flow 75% (23.94 ±3.68 Vs 0.80 ±4.72, p<0.001) and Forced

Expiratory Flow 25-75% (32.50 ±4.79 Vs 3.64 ±3.32, p<0.001) was significantly higher in

the responsive than non-responsive subgroup of the smokers.

Conclusion

The occurrence of peripheral airway resistance is more in the responsive than nonresponsive

subset of smokers to the exercise challenge and hence more prone to

develop obstructive airway disease in the long run.