OBJECTIVES: We investigated the validity of the dipstick method (Mossman Associates Inc. USA) and the expired CO method to distinguish between smokers and nonsmokers. We also elucidated the related factors of the two methods. METHODS: This study included 244 smokers and 50 exsmokers, recruited from smoking cessation clinics at 4 local public health centers, who had quit for over 4 weeks. We calculated the sensitivity, specificity and Kappa coefficient of each method for validity. We obtained ROC curve, predictive value and agreement to determine the cutoff of expired air CO method. Finally, we elucidated the related factors and compared their effect powers using the standardized regression coefficient. RESULTS: The dipstick method showed a sensitivity of 92.6%, specificity of 96.0% and Kappa coefficient of 0.79. The best cutoff value to distinguish smokers was 5-6ppm. At 5 ppm, the expired CO method showed a sensitivity of 94.3%, specificity of 82.0% and Kappa coefficient of 0.73. And at 6 ppm, sensitivity, specificity and Kappa coefficient were 88.5%, 86.0% and 0.64, respectively. Therefore, the dipstick method had higher sensitivity and specificity than the expired CO method. The dipstick and expired CO methods were significantly increased with increasing smoking amount. With longer time since the last smoking, expired CO showed a rapid decrease after 4 hours, whereas the dipstick method showed relatively stable levels for more than 4 hours. CONCLUSIONS: The dipstick and expired CO methods were both good indicators for assessing smoking status. However, the former showed higher sensitivity and specificity and stable levels over longer hours after smoking, compared to the expired CO method.
Adult ; Carbon Monoxide/*analysis/metabolism ; Cotinine/metabolism/*urine ; Female ; Humans ; Male ; Middle Aged ; ROC Curve ; Sensitivity and Specificity ; Smoking/*metabolism/urine

CYP1A2, CYP2D6 and N-acetyltransferase activities were estimated in 100 patients with bladder cancer and 84 control subjects from measurements of theophylline, metoprolol and isoniazid and their metabolites in urine, respectively. The frequency of occurrence of slow acetylators of isoniazid and poor metabolizers of metoprolol were 16.7% and 1.2% in the control group and 16.3% and 2.0% in the cancer patient group. These differences were not significant. The recovery ratio of 1-methyluric acid(1-MU) from theophylline was significantly higher in patients with bladder cancer than in control subjects(0.340 +/- 0.016 versus 0.260 +/- 0.020, p< 0.05). The 1-MU recovery ratio was a significant, independent risk factor among the metabolic capacities tested as shown by logistic regression analysis, controlling for N-acetylation of isoniazid, hydroxylation of metoprolol, age, sex, and smoking. We concluded that the capacity for 3-demethylation of theophylline, as a reflection of CYP1A2 activity, is significantly associated with increased risk of nonoccupational urinary bladder cancer.
Acetylation ; Adult ; Aged ; Amines/metabolism ; Bladder Neoplasms/enzymology/*epidemiology ; Carcinoma, Transitional Cell/enzymology/*epidemiology ; Case-Control Studies ; Cytochrome P-450 CYP1A2 ; Cytochrome P-450 CYP2D6 ; Cytochrome P-450 Enzyme System/metabolism/*urine ; Disease Susceptibility ; Enzyme Induction ; Female ; Human ; Isoniazid/*pharmacokinetics ; Korea/epidemiology ; Logistic Models ; Male ; Methylation ; Metoprolol/*pharmacokinetics ; Middle Age ; Mixed Function Oxygenases/metabolism ; Mixed Function Oxygenases/metabolism ; Oxidoreductases/*urine ; Smoking ; Support, Non-U.S. Gov't ; Theophylline/*pharmacokinetics ; Uric Acid/analogs & derivatives/urine

It has been suggested that there is an association between environmental, low-level arsenic exposure and the risk of diabetes mellitus (DM), but little research has been conducted. Here, the glucose tolerance status and urinary creatinine adjusted total arsenic concentrations were analyzed in 3,602 subjects > or = 20 yr of age who were registered for the Korea National Health and Nutrition Examination Survey, 2008-2009. Various demographic parameters were associated with urinary arsenic concentrations. After adjusting for these variables, urinary arsenic concentrations in subjects with DM were significantly higher than those in subjects with normal glucose tolerance and those with impaired fasting glucose (P < 0.001). Compared with the lowest quartile ( < 70.7 microg/g creatinine), the odds ratios and 95% confidence intervals for DM were 1.11 (0.73-1.68), 1.42 (0.94-2.13), and 1.56 (1.03-2.36) for urinary arsenic concentrations of 70.7 to < 117.7, 117.7 to < 193.4, and > or = 193.4 microg/g creatinine, respectively, following multivariate adjustment. Furthermore, the urinary total arsenic concentration was inversely associated with the insulin secretion index, HOMA2 %B (beta = -0.033, P = 0.032). These findings suggest that arsenic exposure, possibly involving beta cell dysfunction, is associated with an increased risk of DM in the Korean population.
Adult ; Alcohol Drinking ; Arsenic/*urine ; Asian Continental Ancestry Group ; Blood Glucose/analysis ; Diabetes Mellitus/*epidemiology/etiology ; Female ; Glucose Tolerance Test ; Humans ; Insulin/metabolism ; Insulin Resistance ; Male ; Middle Aged ; Nutrition Surveys ; Odds Ratio ; Prevalence ; Republic of Korea/epidemiology ; Risk Factors ; Smoking