Effect of MDR C3435T polymorphism on Varenicline treatment in quit smoking

Despite so many global efforts, smoking still remains to be one of the most common addictions worldwide. Even though most smokers wish to quit smoking, many of them fail. In this respect, genetic variants are thought to be remarkable factors in nicotine dependence and in treatment of smoking cessation. This is a paper investigating a single variant p-glycoprotein (P-gp) polymorphisms and its effect on Varenicline efficacy in the smoking cessation. 158 smokers and 52 non-smoker healthy volunteers were included. We determined the P-gp C3435T gene polymorphisms in all subjects. Face to face interviews with smokers were performed for smoking cessation and Varenicline was given for smoking cessation. Cessation success was evaluated in the 6th month and success rates were compared according to the P-gp genotype distributions. In our study, smoking cessation rate by Varenicline was 57.0%. This rate was 55.0% in females, and 57.2% in males (p=0.85). The P-gp C3435T gene distribution was similar in control, quitters and not-quitter groups. Cessation rate was at highest point in genotype CT (62.2%) and at the lowest in TT (47.6%). It was 53.8% in genotype CC and there was no statistically significant difference (p=0.27). Our results suggest that genetic variants of P-gp C3435T did not significantly affect Varenicline treatment for smoking cessation.

Prevalence of smoking and reasons for continuing to smoke: a population-based study / Prevalência de tabagismo e motivos para continuar a fumar: estudo de base populacional

ABSTRACT Objective: To investigate the prevalence of smoking and the reasons for continuing to smoke among adults in Brazil. Methods: This was a cross-sectional, population-based study including 1,054 individuals ≥ 40 years of age, residents of the city of Florianopolis, Brazil, of whom 183 were smokers. All of the smokers completed the University of São Paulo Reasons for Smoking Scale (USP-RSS). Depressive symptoms were evaluated with the Hospital Anxiety and Depression Scale, and spirometry was performed to screen for COPD. Results: Of the 183 smokers, 105 (57.4%) were female, 138 (75.4%) were White, and 125 (63.8%) were in a low economic class. The mean level of education among the smokers was 9.6 ± 6.1 years. The mean smoking history was 29 ± 15 pack-years, 59% of the men having a ≥ 30 pack-year smoking history. Approximately 20% of the smokers had COPD, and 29% had depressive symptoms, which were more common in the women. The USP-RSS scores were highest for the pleasure of smoking (PS), tension reduction (TR), and physical dependence (PD) domains (3.9 ± 1.1, 3.6 ± 1.2, and 3.5 ± 1.3, respectively). Scores for the PS, TR, and weight control (WC) domains were significantly higher in women. Smokers with a > 20 pack-year smoking history scored significantly higher on the PD, PS, automatism, and close association (CA) domains. Smoking history was associated with the PD, PS, TR, and CA domains. Depressive symptoms were associated with the PD, social smoking, and CA domains (p = 0.001; p = 0.01; p = 0.09, respectively). Female gender and a low level of education were associated with the PS domain (p = 0.04) and TR domain (p < 0.001). Conclusions: The prevalence of smoking in our sample was relatively high (17.4%). The USP-RSS domains PS, TR, and WC explain why individuals continue smoking, as do depressive symptoms.

RESUMO Objetivo: Investigar a prevalência de tabagismo e as razões para continuar a fumar em adultos no Brasil. Métodos: Estudo transversal de base populacional com 1.054 indivíduos com idade ≥ 40 anos residentes em Florianópolis (SC), dos quais 183 eram tabagistas. Todos os fumantes preencheram a Escala Razões para Fumar da Universidade de São Paulo (ERF-USP). Os sintomas de depressão foram avaliados por meio da Hospital Anxiety and Depression Scale, e a presença ou ausência de DPOC foi determinada por meio de espirometria. Resultados: Dos 183 fumantes, 105 (57,4%) eram do sexo feminino, 138 (75,4%) eram brancos e 125 (63,8%) pertenciam a uma classe econômica baixa. A média de escolaridade entre os fumantes foi de 9,6 ± 6,1 anos. A média de carga tabágica foi de 29 ± 15 anos-maço, e 59% dos homens apresentavam carga tabágica ≥ 30 anos-maço. Aproximadamente 20% dos fumantes apresentavam DPOC, e 29% apresentavam sintomas de depressão, mais comuns entre as mulheres. A pontuação obtida na ERF-USP foi maior nos domínios prazer de fumar (PF), redução da tensão (RT) e dependência física (DF): 3,9 ± 1,1; 3,6 ± 1,2 e 3,5 ± 1,3, respectivamente. A pontuação obtida nos domínios PF, RT e controle de peso (CP) foi significativamente maior entre as mulheres. Fumantes com carga tabágica > 20 anos-maço obtiveram pontuação significativamente maior nos domínios DF, PF, automatismo e associação estreita (AE). A carga tabágica relacionou-se com os domínios DF, PF, RT e AE. Sintomas de depressão relacionaram-se com os domínios DF, tabagismo social e AE (p = 0,001; p = 0,01; p = 0,09, respectivamente). Sexo feminino e baixa escolaridade relacionaram-se com os domínios PF (p = 0,04) e RT (p < 0,001). Conclusões: A prevalência de tabagismo em nossa amostra foi relativamente alta (17,4%). Os domínios PF, RT e CP da ERF-USP, bem como os sintomas de depressão, explicam por que os indivíduos continuam a fumar.