Salivary cotinine, frequency of cigarette smoking, and body mass index: findings at baseline in the Lung Health Study.

This study investigates the relation of salivary cotinine and of the reported number of cigarettes smoked per day to body mass index among middle-aged male (n = 3,538) and female (n = 2,096) cigarette smokers participating in screening for entry to a clinical trial of early intervention in chronic obstructive pulmonary disease (Lung Health Study) from 1986 to 1989. Both before and after controlling for age, education, and alcohol intake, the number of cigarettes smoked per day was positively related to body mass index among both men and women, whereas salivary cotinine levels were negatively related to body mass index among both men and women. The opposite relation of salivary cotinine and of reported number of cigarettes smoked per day to body mass index is discussed with regard to nicotine metabolism, energy intake, and measurement issues in the assessment of cigarette smoke exposure.