Tabagismo e variação ponderal: a fisiopatologia e genética podem explicar esta associação?

Abstract

Tobacco use is the leading preventable cause of death in most countries, including Brazil. Smoking cessation is an important strategy for reducing the morbidity and mortality associated with tobacco-related diseases. An inverse relationship between nicotine use and body weight has been reported, in which body weight tends to be lower among smokers than among nonsmokers. Smoking abstinence results in an increase in body weight for both males and females. On average, sustained quitters gain from 5 to 6 kg, although approximately 10% gain more than 10 kg. Pharmacological treatment for smoking cessation attenuates weight gain. The importance of smoking cessation as a contributing cause of the current obesity epidemic has been little studied. In the USA, the rate of obesity attributable to smoking cessation has been estimated at approximately 6.0 and 3.2% for males and females, respectively. Although the mechanisms are unclear, there is evidence that dopamine and serotonin are appetite suppressants. The administration of nicotine, regardless of the delivery system, acutely raises the levels of these neurotransmitters in the brain, reducing the need for energy intake and consequently suppressing appetite. In addition, nicotine has a direct effect on adipose tissue metabolism, influencing the rate of weight gain following smoking cessation. Leptin, ghrelin and neuropeptide Y are substances that might constitute factors involved in the inverse relationship between nicotine and body mass index, although their roles as determinants or consequences of this relationship have yet to be determined. Smoking and body weightThe inter-relationship between smoking and body weight has been well established in various well-designed studies, most of which were published in the 1990s. (10,11) The body mass index (BMI) of smokers is frequently present lower than that of age-and gender-matched nonsmokers. In addition, comprehensive cross-sectional epidemiological studies, some of which considered to be classical on this subject, showed a significant inverse relationship between the regular tobacco use and body weight, which tends to be lower among smokers than among nonsmokers. (12,13) Smoking cessation results in weight gain both in males and females, and over 75% of smokers gain weight when they become abstinent. (14,15) Mean weight gain attributable to smoking cessation is 2.8 and 3.8 kg in males and females, respectively. In a systematic review of the literature, it was estimated that the mean body weight gain in individuals who quit smoking can reach 5-6 kg, and 13% of ex-smokers can gain more than 10 kg. (10) Although most reports on smoking cessation have indicated mid-and long-term weight gain, other studies have shown that the most critical period is immediately after smoking cessation. (10) In one study, (16) the increase in body weight was 5.2 and 4.9 kg in females and males, respectively, during the first year after cessation, with an increase of 3.4 and 2.6 kg, respectively, in the following years. In the same stud...

Association between Smoking and Anthropometric Characteristics, Biochemical Markers, and Dietary Intake of Pakistani Male Adult Population

“…Similarly, Chopra, et al 32 and AL-Riyami and Afifi 33 also reported no significant difference in the mean BMI between the smokers and non-smokers. Conversely, others 34,35 reported an inverse association between nicotine intake and body weight; while another group of researchers noted a positive association between obesity and number of cigarettes smoked per day.…”

Prevalência e fatores associados à obesidade abdominal em indivíduos na faixa etária de 25 a 59 anos do Estado de Pernambuco, Brasil

“…Nessa situação de cessação do tabagismo, ocorre uma diminuição da taxa metabólica basal, podendo variar entre 4% e 16%, o que representaria menos de 40% do ganho ponderal 23 . Na fase de cessação, há o consumo preferencial de alimentos especialmente ricos em gorduras e açúcares 24 .…”

Hormonal, metabolic and nutritional alterations in smokers: emergency for smoking abstinence

“…Studies suggest that nicotine promotes increased energy expenditure and reduces appetite, which explains why smokers having a lower BMI than nonsmokers, and the common weight gain after smoking cessation 12,31,32 . In contrast, it is observed that heavy smokers (> 40 cigarettes/day) tend to have higher body weight than light smokers (< 20 cigarettes/day).…”