Self-reported smoking status and urinary cotinine levels in patients with asthma / Tabagismo entre asmáticos: avaliação por autorrelato e dosagem de cotinina urinária

ABSTRACT Objective: To determine the frequency of active smoking among patients with asthma and individuals without asthma by self-report and urinary cotinine measurement. Methods: This was a cross-sectional study conducted in the city of Salvador, Brazil, and involving 1,341 individuals: 498 patients with severe asthma, 417 patients with mild-to-moderate asthma, and 426 individuals without asthma. Smoking status was determined by self-report (with the use of standardized questionnaires) and urinary cotinine measurement. The study variables were compared with the chi-square test and the Kruskal-Wallis test. Results: Of the sample as a whole, 55 (4.1%) reported being current smokers. Of those, 5 had severe asthma, 17 had mild-to-moderate asthma, and 33 had no asthma diagnosis. Of the 55 smokers, 32 (58.2%) were daily smokers and 23 (41.8%) were occasional smokers. Urinary cotinine levels were found to be high in self-reported nonsmokers and former smokers, especially among severe asthma patients, a finding that suggests patient nondisclosure of smoking status. Among smokers, a longer smoking history was found in patients with severe asthma when compared with those with mild-to-moderate asthma. In addition, the proportion of former smokers was higher among patients with severe asthma than among those with mild-to-moderate asthma. Conclusions: Former smoking is associated with severe asthma. Current smoking is observed in patients with severe asthma, and patient nondisclosure of smoking status occurs in some cases. Patients with severe asthma should be thoroughly screened for smoking, and findings should be complemented by objective testing.

RESUMO Objetivo: Descrever a frequência de tabagismo ativo entre pacientes com asma e indivíduos sem asma, usando questionários padronizados e dosagem da cotinina urinária. Métodos: Estudo transversal realizado em Salvador (BA), com 1.341 indivíduos, sendo 498 com asma grave, 417 com asma leve/moderada e 426 sem asma. O tabagismo foi identificado por meio de autorrelato utilizando questionários e por mensuração da cotinina urinária. Para a comparação das variáveis estudadas, utilizaram-se os testes do qui-quadrado e de Kruskal-Wallis. Resultados: Dos 55 participantes (4,1%) que se declararam tabagistas atuais, 5, 17 e 33 eram dos grupos asma grave, asma leve/moderada e sem asma, respectivamente. Desses 55, 32 (58,2%) eram tabagistas diários e 23 (41,8%) eram tabagistas ocasionais. Observaram-se níveis elevados de cotinina urinária entre não fumantes autodeclarados e tabagistas pregressos, especialmente no grupo asma grave, o que sugere omissão do hábito atual de fumar. A carga tabágica entre os fumantes e a proporção de ex-tabagistas foram maiores no grupo asma grave do que no grupo asma leve/moderada. Conclusões: O tabagismo pregresso esteve associado à asma grave. Tabagismo atual também foi observado em alguns pacientes com asma grave e detectou-se omissão em alguns casos. A investigação de tabagismo deve ser meticulosa em pacientes com asma grave e a entrevista desses deve ser complementada por uma avaliação objetiva.

Comparison between objective measures of smoking and self-reported smoking status in patients with asthma or COPD: are our patients telling us the truth? / Comparação entre medidas objetivas do tabagismo e tabagismo autodeclarado em pacientes com asma ou DPOC: será que nossos pacientes dizem a verdade?

OBJECTIVE: Smoking prevalence is frequently estimated on the basis of self-reported smoking status. That can lead to an underestimation of smoking rates. The aim of this study was to evaluate the difference between self-reported smoking status and that determined through the use of objective measures of smoking at a pulmonary outpatient clinic. METHODS: This was a cross-sectional study involving 144 individuals: 51 asthma patients, 53 COPD patients, 20 current smokers, and 20 never-smokers. Smoking status was determined on the basis of self-reports obtained in interviews, as well as through tests of exhaled carbon monoxide (eCO) and urinary cotinine. RESULTS: All of the asthma patients and COPD patients declared they were not current smokers. In the COPD and asthma patients, the median urinary cotinine concentration was 167 ng/mL (range, 2-5,348 ng/mL) and 47 ng/mL (range, 5-2,735 ng/mL), respectively (p < 0.0001), whereas the median eCO level was 8 ppm (range, 0-31 ppm) and 5 ppm (range, 2-45 ppm), respectively (p < 0.05). In 40 (38%) of the patients with asthma or COPD (n = 104), there was disagreement between the self-reported smoking status and that determined on the basis of the urinary cotinine concentration, a concentration > 200 ng/mL being considered indicative of current smoking. In 48 (46%) of those 104 patients, the self-reported non-smoking status was refuted by an eCO level > 6 ppm, which is also considered indicative of current smoking. In 30 (29%) of the patients with asthma or COPD, the urinary cotinine concentration and the eCO level both belied the patient claims of not being current smokers. CONCLUSIONS: Our findings suggest that high proportions of smoking pulmonary patients with lung disease falsely declare themselves to be nonsmokers. The accurate classification of smoking status is pivotal to the treatment of lung diseases. Objective measures of smoking could be helpful in improving clinical management ...

OBJETIVO: O tabagismo autodeclarado é usado frequentemente para estimar a prevalência dessa condição. As taxas de tabagismo podem ser subestimadas por esse método. O objetivo deste estudo foi avaliar a diferença entre o tabagismo autodeclarado e o tabagismo determinado pelo uso de medidas objetivas em um ambulatório de doenças respiratórias. MÉTODOS: Estudo transversal realizado em 144 indivíduos: 51 pacientes com asma, 53 pacientes com DPOC, 20 fumantes e 20 não fumantes. O tabagismo foi determinado por meio de autorrelato em entrevistas e medição de monóxido de carbono no ar exalado (COex) e de cotinina urinária. RESULTADOS: Todos os pacientes com asma e DPOC declararam não ser fumantes. Nos pacientes com DPOC e asma, a mediana de concentração de cotinina urinária foi de 167 ng/ml (variação, 2-5.348) e de 47 ng/ml (variação, 5-2.735 ppm), respectivamente (p < 0,0001), enquanto . a mediana de COex foi de 8 ppm (variação, 0-31) e 5,0 ppm (variação, 2-45 ppm), respectivamente (p < 0,05). Em 40 (38%) dos pacientes com asma ou DPOC (n = 104), houve discordâncias entre o tabagismo autodeclarado e a concentração de cotinina urinária (> 200 ng/mL). Em 48 (46%) desses 104 pacientes, o não tabagismo autodeclarado foi refutado por um nível de COex > 6 ppm, considerado indicativo de fumo atual. Em 30 (29%) dos pacientes com asma ou DPOC, a concentração de cotinina urinária e o nível de COex contradisseram o autorrelato desses como não fumantes. CONCLUSÕES: Nossos achados sugerem que altas proporções de pacientes fumantes com doenças respiratórias declaram ser não fumantes. A classificação correta do tabagismo é fundamental no tratamento dessas doenças. Medidas objetivas do tabagismo podem ser úteis na melhora do manejo clínico e no aconselhamento. .

Comparison of Urinary Protein Creatinine Index (uPCI) and Dipsticks for the Prediction of Renal Dysfunction in Chronic Cigarette Smokers.

Background: Proteinuria is recognized as one of the earliest sign of renal function deterioration in chronic smokers. Proteinuria occurs due to alteration in glomerular permeability and later due to failure of reabsorption of filtered protein by the tubular cells. Normally, most healthy adults excrete 20 – 150 mg of protein in urine over 24 hours. However, it is difficult to collect 24 hrs urine samples. Objectives: To advocate the use of PCI (protein creatinine index) in assessment of proteinuria and to compare dipstick result with PCI in the assessment of proteinuria in chronic cigarette smokers. Material & Methods: A total of 30 cigarette smokers and 40 age and sex matched controls were included for the study. A random specimen of urine collected from each cigarette smoker and non- smoker was tested quantitatively by manual sulfosalicylic acid colorimetric method for the estimation of protein concentration. Creatinine concentration in each specimen was measured by modified Jaffe’s method and the urinary PCI was calculated. Results: Normal range of PCI which has been established in this study is 50 to 259. Significantly higher amounts of protein were found to be excreted in urine in chronic smokers (9.313 ± 4.003 mg/dl) as compared to healthy non smokers (7.738 ± 2.05 mg/dl). On comparison of PCI between healthy non smoker and chronic smoker subjects, PCI has been found to be significantly elevated in chronic smokers (healthy non smoker- 118.32 ± 56.86, chronic smoker- 180.1 ± 88.23) (p=0.001). Conclusion: PCI of random urine sample can provide a very useful, simple and convenient method for the quantitative assessment of proteinuria to confirm the advent of kidney damage, avoiding the drawbacks of 24 hrs urine collection.

A study of the status of exposure to polycyclic aromatic hydrocarbons (PAHs) in relation to its metabolites among workers in a Korean chemical factory / Um estudo sobre o estado de exposição a hidrocarbonetos aromáticos policíclicos (HAPs), em relação aos seus metabolitos, entre os trabalhadores em fábricas de produtos químicos coreana

The study was conducted to evaluate the status of worker exposure to polycyclic aromatic hydrocarbons (PAHs) through the measurement of urinary metabolites such as 1-hydroxypyrene (OHP) and 2-naphthol. A survey using a questionnaire involving 326 workers with measurement of urinary metabolites of 1-OHP and 2-naphthol was conducted. The differences in urinary 1-OHP and 2-naphthol concentrations, and changes in work, smoking habits and lifestyle were analyzed. The number of male subjects was 314 (96.3%), the largest age group was the fifth decade (170 cases, 52.1%). The urinary 1-OHP and 2-naphthol concentrations were significantly higher in the production workers. The urinary 1-OHP and 2-naphthol concentrations were significantly higher in smokers. In a multiple regression model, log (1-OHP) increased in smokers and production workers, while log (2-naphthol) only increased in smokers. Our results suggest that workers in this factory were exposed to PAHs from non-occupational as well as occupational sources. The occupational exposure to PAHs can be reduced through the improvement of the process, but the exposure due to smoking can be prevented only by giving up smoking.

O presente estudo foi realizado para avaliar o estado de exposição a hidrocarbonetos aromáticos policíclicos (HAPs) em trabalhadores, por medição de metabólitos urinários, tais como 1-hidroxipireno (OHP) e 2-naftol. Foi realizada uma pesquisa por questionário envolvendo 326 trabalhadores e a mensuração dos metabólitos urinários de 1-OHP e 2-naftol. Foram analisadas as diferenças na urinária 1-OHP e as concentrações de 2-naftol e mudanças pelo trabalho, hábito de fumar e estilo de vida. O número de indivíduos do sexo masculino foi de 314 (96,3%), a maior faixa etária foi a quinta década (170 casos, 52,1 %). Com relação aos metabólitos urinários 1 -OHP e 2-naftol, as concentrações foram significativamente maiores nos trabalhadores produtivos. As concentrações dos metabólitos urinários 1-OHP e 2-naftol foram significativamente maiores nos fumantes. Em um modelo de regressão múltipla, log (1-OHP) aumentou em fumantes e em trabalhadores produtivos, enquanto que log (2-naftol) aumentou apenas em fumantes. Nossos resultados sugerem que os trabalhadores desta fábrica foram expostos tanto a HAPs de fontes não ocupacionais como ocupacionais. A exposição ocupacional a HAPs pode ser diminuída através da melhoria do processo, mas a exposição devido ao fumo só pode ser impedida interrompendo esse hábito.

Single gas chromatography method with nitrogen phosphorus detector for urinary cotinine determination in passive and active smokers

Nicotine is a major addictive compound in cigarettes and is rapidly and extensively metabolized to several metabolites in humans, including urinary cotinine, considered a biomarker due to its high concentration compared to other metabolites. The aim of this study was to develop a single method for determination of urinary cotinine, in active and passive smokers, by gas chromatography with a nitrogen phosphorus detector (GC-NPD). Urine (5.0 mL) was extracted with 1.0 mL of sodium hydroxide 5 mol L-1, 5.0 mL of chloroform, and lidocaine used as the internal standard. Injection volume was 1 ìL in GC-NPD. Limit of quantification was 10 ng mL-1. Linearity was evaluated in the ranges 10-1000 ng mL-1 and 500-6000 ng mL-1, with determination coefficients of 0.9986 and 0.9952, respectively. Intra- and inter-assay standard relative deviations were lower than 14.2 %, while inaccuracy (bias) was less than +11.9%. The efficiency of extraction was greater than 88.5%. Ruggedness was verified, according to Youden's test. Means of cotinine concentrations observed were 2,980 ng mL-1 for active smokers and 132 ng mL-1, for passive smokers. The results revealed that satisfactory chromatographic separation between the analyte and interferents was obtained with a ZB-1 column. This method is reliable, precise, linear and presented ruggedness in the range evaluated. The results suggest that it can be applied in routine analysis for passive and active smokers, since it is able to quantify a wide range of cotinine concentrations in urine.

A nicotina é uma substância presente no cigarro capaz de causar dependência, sendo biotransformada em vários metabólitos nos seres humanos, dentre eles a cotinina urinária, que é considerada um indicador biológico de exposição à nicotina, devido a suas altas concentrações, comparado a outras matrizes. Assim, o objetivo deste estudo foi desenvolver um único método para determinação de cotinina urinária, em amostras de urina de fumantes ativos e passivos, através de cromatografia em fase gasosa com detector de nitrogênio- fósforo (CG-DNF). Para o preparo de amostras foram utilizados 5 mL de urina, 1 mL de hidróxido de sódio 5 mol L-1, 5 mL de clorofórmio, tendo como padrão interno a lidocaína. Na faixa de concentrações de 10-1000 ng mL-1 e 500- 6000 ng mL-1, o coeficiente de determinação foi 0,9986 e 0,9952, respectivamente e, o limite de quantificação foi 10 ng mL-1. A precisão intra- e interensaio apresentou desvio padrão relativo (%) menor que 14,2% e a inexatidão foi menor que +11,9%, com uma eficiência de extração de 88,5%. O método apresentou robustez, de acordo com o teste de Youden. As concentrações médias de cotinina observadas foram 2980 ng mL-1, para fumantes ativos e 132 ng mL-1, para fumantes passivos. Os resultados sugerem que o método é confiável, preciso, linear e apresentou robustez, na faixa avaliada, podendo ser aplicado na rotina para análises de amostras de fumantes ativos e passivos, pois é capaz de quantificar uma ampla faixa de concentrações de cotinina urinária.

Avaliação da concentração de monóxido de carbono no ar exalado em tabagistas com DPOC / Evaluation of the exhaled carbon monoxide levels in smokers with COPD

OBJETIVO: Medir os níveis de monóxido de carbono no ar exalado (COex) em tabagistas com e sem DPOC. MÉTODOS: Tabagistas frequentadores dos ambulatórios do Hospital São Lucas em Porto Alegre (RS) entre setembro de 2007 e março de 2009 foram convidados a participar do estudo. Os participantes responderam a um questionário com características demográficas e epidemiológicas e realizaram espirometria, medição de cotinina urinária e de COex. Os participantes foram agrupados conforme a presença de DPOC. RESULTADOS: Foram incluídos 294 tabagistas, 174 (59,18 por cento) diagnosticados com DPOC. Todos os participantes apresentavam níveis de cotinina urinária > 50 ng/mL. Os fumantes com DPOC apresentaram medianas significativamente superiores as do grupo sem DPOC para as variáveis idade e maços-ano (p < 0,001 e p = 0,026, respectivamente). Não houve diferença significativa nas demais variáveis. Quando ajustados para sexo, início do tabagismo, cigarros/dia e cotinina urinária, os valores médios de COex foram mais altos no grupo DPOC que no grupo sem DPOC, mas sem significância estatística (17,8 ± 0,6 ppm e 16,6 ± 0,7 ppm, respectivamente; p = 0,200). As diferenças permaneceram não significativas quando o método de base logarítmica foi usado. Uma ampla dispersão dos valores de COex foi encontrada quando os participantes foram classificados conforme os valores de VEF1 (r = -0,06; p = 0,53) ou o sistema de classificação de Global Initiative for Chronic Obstructive Lung Disease (r = 0,08; p = 0,34). As proporções de resultados falso-negativos para tabagismo foram de 18,4 por cento e 6,7 por cento, respectivamente, nos grupos com e sem DPOC (p = 0,007). CONCLUÕES: Esse estudo mostrou que os valores de COex não apresentaram diferenças significativas em fumantes com ou sem DPOC. Desse modo, parece não haver nenhuma restrição relevante para a sua aplicabilidade em fumantes com DPOC.

OBJECTIVE: To measure exhaled carbon monoxide (COex) levels in smokers with and without COPD. METHODS: Smokers treated at outpatient clinics of São Lucas Hospital in the city of Porto Alegre, Brazil, between September of 2007 and March of 2009 were invited to participate in this study. The participants completed a questionnaire regarding demographic and epidemiologic characteristics and were submitted to spirometry, as well as to determination of COex and urinary cotinine levels. The participants were divided into two groups: those with COPD and those without COPD. RESULTS: The study involved 294 smokers, of whom 174 (59.18 percent) had been diagnosed with COPD. All of the participants presented with urinary cotinine levels > 50 ng/mL. Smokers with COPD presented significantly higher median values for age and pack-years than did those without COPD (p < 0.001 and p = 0.026, respectively). No other statistically significant differences were found. When adjusted for gender, age at smoking onset, number of cigarettes/day and urinary cotinine level, the mean values of COex were higher, but not statistically so, in the COPD group than in the non-COPD group (17.8 ± 0.6 ppm and 16.6 ± 0.7 ppm, respectively; p = 0.200). The differences remained nonsignificant when plotted logarithmically. A wide dispersion of COex values was found when the participants were classified by FEV1 level (r = -0.06; p = 0.53) or by Global Initiative for Chronic Obstructive Lung Disease classification (r = 0.08; p = 0.34). The proportions of false-negative results for smoking were 18.4 percent and 6.7 percent, respectively, in the COPD and non-COPD groups (p = 0.007). CONCLUSIONS: Since COex values did not differ significantly between smokers with COPD and those without, there seem to be no major contraindications to their use in smokers with COPD.

Spot urine porphyrins/creatinine ratio profile of healthy Brazilian individuals adjusted for personal habits

Changes in urinary porphyrin excretion may be the result of hereditary causes and/or from environmental or occupational exposure. The objective of this study was to measure the amount of some porphyrins in spot urine samples obtained from volunteers randomly selected from a healthy adult population of São Paulo with a sensitive HPLC method and to estimate normal ranges for a non-exposed population. Spot urine samples were collected from 126 subjects (both genders, 18 to 65 years old) not occupationally exposed to porphyrinogenic agents. Porphyrin fractions were separated on RP-18 HPLC column eluted with a methanol/ammonium acetate buffer gradient, pH 4.0, and measured fluorometrically (excitation 405 nm/emission 620 nm). The amount of porphyrins was corrected for urinary creatinine excretion. Only 8-carboxyl (uro) and 4-carboxyl (copro) porphyrins were quantified as µg/g creatinine. Data regarding age, gender, occupational activities, smoking and drinking habits were analyzed by Mann-Whitney and Kruskal-Wallis tests. Uroporphyrin results did not differ significantly between the subgroups studied. Copro and uro + copro porphyrins were significantly different for smokers (P = 0.008) and occupational activities (P = 0.004). With respect to alcohol consumption, only men drinking >20 g/week showed significant differences in the levels of copro (P = 0.022) and uro + copro porphyrins (P = 0.012). The 2.5-97.5th percentile limit values, excluding those for subjects with an alcohol drinking habit >20 g/week, were 0-20.8, 11.7-93.1, and 15.9-102.9 µg/g creatinine for uro, copro and uro + copro porphyrins, respectively. These percentile limit values can be proposed as a first attempt to provide urinary porphyrin reference values for our population, serving for an early diagnosis of porphyrinopathies or as biomarkers of exposure to porphyrinogenic agents.

Dosagem de microalbuminúria em hipertensos e em pacientes portadores de doença coronariana / Determination of microalbuminuria in hypertensive patients and in patients with coronary artery disease

FUNDAMENTO: A taxa normal de excreção de albumina em 24 horas é de 20 mg. A taxa persistente de 30 a 300 mg/dia é chamada de microalbuminúria (MA) e está relacionada com maior prevalência de doença cardiovascular. OBJETIVO: Determinar a prevalência de microalbuminúria em um grupo de hipertensos e em um grupo de portadores de doença coronariana; e determinar a relação da presença de microalbuminúria com hipertensão arterial, diabete melitus, dislipidemia, tabagismo e obesidade. MÉTODOS:: Determinamos a presença de microalbuminúria num grupo de hipertensos (73 indivíduos) e num grupo de coronariopatas (39 indivíduos), e comparamos com um grupo-controle (43 indivíduos). Considerou-se como microalbuminúria a relação albumina/creatinina maior que 30 e menor que 300 em amostra isolada de urina matinal. Na análise estatística, foram utilizados os testes do qui-quadrado e o teste exato de Fisher. RESULTADOS: A microalbuminúria esteve presente em 9,5 por cento dos hipertensos, em 33 por cento dos coronariopatas e não esteve presente em nenhum indivíduo do grupo-controle. Ao analisar a ocorrência de microalbuminúria segundo os diversos parâmetros clínicos, independentemente do grupo a que pertenciam, verificamos correlação estatisticamente significativa com idade, diabete e dislipidemia. CONCLUSÃO: 1) A prevalência de microalbuminúria em indivíduos hipertensos é elevada, sendo ainda mais elevada em portadores de doença coronariana; 2) existe correlação da presença de microalbuminúria com idade, diabete e dislipidemia.

BACKGROUND: The normal 24-hour albumin excretion rate is of 20 mg. A persistent rate of 30 to 300 mg/day is called microalbuminuria and is related to a higher prevalence of cardiovascular disease. OBJECTIVE: 1) To determine the prevalence of microalbuminuria in a group of hypertensive patients and in a group of patients with coronary artery disease; 2) To determine the relationship between the presence of microalbuminuria and hypertension, diabetes mellitus, dyslipidemia, smoking and obesity. METHODS: The presence of microalbuminuria in a group of hypertensive patients (73 individuals) and in a group of patients with coronary artery disease (39 individuals) was determined and compared with a control group (43 individuals). Microalbuminuria was defined as an albumin/creatinine ratio higher than 30 and lower than 300 in a spot morning urine sample. The chi-square test and the Fisher’s exact test were used in the statistical analysis. RESULTS: Microalbuminuria was present in 9.5 percent of the hypertensive individuals and in 33 percent of the patients with coronary artery disease, and was absent in individuals of the control group. When the occurrence of microalbuminuria was analyzed according to the different clinical parameters, regardless of the group involved, a statistically significant correlation was found with age, diabetes and dyslipidemia. CONCLUSION: 1) The prevalence of microalbuminuria in hypertensive individuals is high, and is even higher in patients with coronary artery disease; 2) There is a correlation of the presence of microalbuminuria with age, diabetes and dyslipidemia.

Simultaneous determination of trans, transmuconic acid and s-phenylmercapturic acid by high pressure liquid chromatography and its application.

The simultaneous determination of urinary trans,trans-muconic acid (t,t-MA) and S-phenylmercapturic acid (S-PMA) was performed by liquid extraction with ethyl acetate and reversed-phase high performance liquid chromatography (RP-HPLC) on a Hypersil-ODS column using the gradient mobile phase of methanol and 0.0012 N perchloric acid and diode array detection at 205 and 264 nm for S-PMA and t,t-MA, respectively. The retention times for t,t-MA and S-PMA were 3.8 and 12.3 minutes, respectively. The recoveries of t,t-MA and S-PMA were > 97%; between-day precisions were all within 8% RSD (100x SD/mean). The method was applied to analyze the urinary t,t-MA and S-PMA of 59 service station attendants exposed to average benzene concentrations in the air of 0.20+/-0.18 ppm. Significant differences in pre-shift and post-shift urinary t,t-MA between smokers and non-smokers were found.

Cotinina urinaria como indicador de la cesación del hábito tabáquico / Urinary cotinine as indicator of smoking habit cessation

La cotinina es el principal metabolito de la nicotina, su cuantificación se utiliza como indicador de consumo de tabaco y de abstinencia. Objetivo: Establecer los niveles de cotinina urinaria en fumadores que iniciaron y terminaron el progrma de cotinina urinaria y de cesación del tabaquismo de la Clínica de tabaco del Instituto Nacional de Enfermedades Respiratorias (INER). Material y métodos: Se estudiaron un grupo problema integrado por 100 sujetos fumadores inscritos en la Clínica de Tabaquismo del INER y dos grupos control, uno fumador por 50 sujetos NO fumadores y otros formado por 20 sujetos fumadores activos, a los cuales se les determinó el nivel de cotinina urinaria por el mismo método. Resultados: El rango de cotinina urinaria obtenida en sujetos fumadores es sumamente amplio ya que va desde 13 hasta 245 µMol/L (con un promedio de 67 ñ 44 µMol/L), el nivel considerado como frontera entre fumadores y no fumadores fue de 12.4 µmol/L. Se encontró que existe una diferencia estadísticamente significativa en el nivel de cotinina urinaria entre fumadores y no fumadores (p< 0.01). Discusión: Se observó que un programa de cesción del hábito tabáquico conduce a dejar fumar, lo que conduce a una disminución de los niveles de cotinina urinaria, sin embargo, no se encontró correlación entre los niveles de cotinina inicial y final en el 25 por ciento de los pacientes que aceptaron por escrito haber abandonado el tabaquismo, discrepancia que ya había sido informada por otros autores, pero con menor frecuencia