Smoking and use of smokeless tobacco in treated hypertensive men at high coronary risk: utility of urinary cotinine determination

Abstract

Guidelines for the treatment of hypertension underline the central importance of strenuous efforts to reduce the prevalence of smoking, as epidemiological studies consistently have demonstrated that smoking increases the risk of cardiovascular disease and death by some two- or three-fold. Accuracy of a questionnaire is examined against the ability of urinary cotinine determination to distinguish between men exposed to tobacco (94 smokers [25 %], 30 snuff users [8 %]) and men not exposed (n=257), all of whom where treated hypertensives and were associated with at least one of the following factors: smoking, diabetes mellitus, serum cholesterol ≥ 6.5 mmol/L. Main outcome variables in this cross-sectional study of 381 men were cotinine concentration and cotinine:creatinine ratio in overnight urine samples (decision limits: 2 μmol/L and 1.0 mmol/mol, respectively); tobacco use according to questionnaire; and follow-up examination by questionnaire of alleged non-smokers with high urinary cotinine levels. Questionnaire sensitivity was 85%, whereas the urinary cotinine assay showed 98% sensitivity and 99% specificity. Fourteen (15%) out of 94 patients may have used tobacco without reporting it in the questionnaire. In conclusion, cotinine measurement substantially improved the discrimination between smokers and non-smokers in men with multiple risk factors for cardiovascular disease.