Source of Support: None, Conflict of Interest: None
A sample of 456 males and 424 females was selected randomly from among healthy northern Indian subjects and their peak expiratory flow rate was determined by the Wright's peak flow meter to evaluate the effect of various factors influencing it. There was a significant difference of PEFR in both the sexes. The correlation of PEFR with the age was negative in both the sexes, and with anthropometric measurements (height, weight and body surface area) it was positive. Low socio-economic status and moderately or over-crowded area of residence were found to decrease PEFR. Smokers were found to have significantly lower value of PEFR in comparison to nonsmokers. The duration of smoking was found to be a more important factor than the amount of tobacco smoked per day in impairing PEFR. It was also noted that PEFR tended to decline more rapidly among the smokers than the nonsmokers after the age of 40 years. Other factors like type of job (sedentary or hard manual worker) and dietary habit did not show any significant effect on PEFR.