Tobacco smoking is a major risk factor for
cancer,
cardiovascular diseases and respiratory illnesses. Smoking is increasing among children and adolescents with subsequent consequences on the health. Furthermore, maternal tobacco smoking during pregnancy adversely affects prenatal growth.
Nicotine, the most important tobacco
alkaloid, is responsible for maintaining tobacco addiction. According to a recent Circulaire de la direction générale de la santé,
nicotine dependence should be determined through questionnaires and quantitative estimate of
nicotine metabolites.
Nicotine blood level fluctuates and urinary
nicotine excretion is of short duration.
Nicotine is intensively metabolized in the liver and oxidized into
cotinine. Urinary measurement of
cotinine appears to be highly related with the degree of intoxication and to allow the differentiation between non exposed and exposed non-smokers. In order to check the present application of
nicotine metabolites measurement, a survey was conducted in 340 smoking cessation units. Forty percent physicians (n = 137) answered the survey. For 17% of them, the quantification of
nicotine metabolites is included in their daily practise and for 79%, guidelines about
cotinine measurement should be given in France. Sixty-seven biologists answered the survey. Recommendations for immunoassay and HPLC determination of
cotinine should be given as reported by 66 and 44% of them respectively. Indeed, urinary
cotinine measurement with high performance liquid chromatography is highly sensitive and specific. However, immunoassays are more convenient. These two approaches are presently under investigation in order to provide guidelines for optimal use in various clinical situations. Traditional measures for
nicotine dependence are the number of cigarettes smoked per day,
nicotine intake expressed as mg per day, Fagerstr m questionnaire, expired air
carbon monoxide,
thiocyanates and
cotinine levels in
biological fluids. Urinary
cotinine measurement is the most useful for the follow-up of smoking cessation including adjustment of
nicotine replacement therapy, especially after a clinical event or for the follow-up of smoking pregnant women. It allows the detection of passive
smoke exposure in children who are hospitalized for recurrent respiratory illnesses.