Efeitos agudos do tabagismo sobre a modulação autonômica: análise por meio do plot de poincaré

FUNDAMENTO: O tabagismo altera a função autonômica. OBJETIVO: Investigar os efeitos agudos do tabagismo sobre a modulação autonômica e a recuperação dos índices de variabilidade de frequência cardíaca (VFC) pós-fumo, por meio do plot de Poincaré e índices lineares. MÉTODOS: Foram avaliados 25 fumantes jovens, os quais tiveram a frequência cardíaca analisada, batimento a batimento, na posição sentada, após 8 horas de abstinência, por 30 minutos em repouso, 20 minutos durante o fumo e 30 minutos pós-fumo. Análise de variância para medidas repetidas, seguido do teste de Tukey, ou teste de Friedman seguido do teste de Dunn foram aplicados dependendo da normalidade dos dados, com p < 0,05. RESULTADOS: Durante o fumo, houve redução dos índices SD1 (23,4 ± 9,2 vs 13,8 ± 4,8), razão SD1/SD2 (0,31 ± 0,08 vs 0,2 ± 0,04), RMSSD (32,7 ± 13 vs 19,1 ± 6,8), SDNN (47,6 ± 14,8 vs 35,5 ± 8,4), HFnu (32,5 ± 11,6 vs 19 ± 8,1) e do intervalo RR (816,8 ± 89 vs 696,5 ± 76,3) em relação ao repouso, enquanto que aumentos do índice LFnu (67,5 ± 11,6 vs 81 ± 8,1) e da razão LF/HF (2,6 ± 1,7 vs 5,4 ± 3,1) foram observados. A análise visual do plot mostrou menor dispersão dos intervalos RR durante o fumo. Com exceção da razão SD1/SD2, os demais índices apresentaram recuperação dos valores, 30 minutos após o tabagismo. CONCLUSÃO: O tabagismo produziu agudamente modificações no controle autonômico, caracterizadas por ativação simpática e retirada vagal, com recuperação 30 minutos após o fumo.

Ocorrência de tabagismo e dependência nicotínica em universitários

In Brazil, smoking incidence varies between 9.5% and 21.2% and it is more common among men. In college students incidence can reach 14% depending on the region, which is quite disturbing. Joining college is a crucial period for the commencement or maintenance of smoking. The Knowledge among college students about tobacco use is critical to devise strategies for intervention in this population. The objectives were to establish the occurrence of smoking and risk factors, nicotine dependence in college students and college goers. We interviewed students, teachers and administrative personnel from the Philosophy and Science School at UNESP at Marilia, from both sexes, regardless their age, which visited the First Week Against Tobacco event. The sociodemographic data, smoking status, time as a smoker, cigarettes smoked, date when they started smoking, history of smoking in the family, friends or associates were questioned. We also assessed the degree of motivation to quit smoking and the degree of nicotine dependence. Data were presented using descriptive statistics. Comparisons between categorical variables were made using the chi-square test (p <0.05). A total of 432 people, 180 men and 252 women, average aged 22.6 ± 6.9 years were researched. From the volunteers studied, 267 (61.8) had tried cigarettes and 171 of them (64%) reported that they were offered by friends. As a whole, 79 (18.3%) of these people were smokers, 52 (65.8%) reported intending to quit smoking and in 37 of them (46.8%), the degree of nicotine dependence was very low. Of all the smokers, 63 had smokers in the family and all of them had friends who smoked. 28.9% of all men were smokers and 10.7%of all women. The occurrence of smoking was 18.3% and the risk factor associated to smoking habit is related to friendship and family, and very low nicotine dependence.