Efeito da dieta hiperlipídica sobre a composição corporal de camundongos jovens, fêmeas e machos, expostos à fumaça de cigarro e a resposta à abstinência

Abstract

Changes in nutritional pattern, including increased lipid intake by the diet, mainly associated with vegetable oils, are directly related to disorders resulting from the development of overweight and obesity. Another detrimental factor to life quality, which affects young people considerably, is smoking. Therefore, the association of these two factors represents a health problem. Thus, the objective of this study was to evaluate the effect of a high-fat diet containing soybean oil on food intake and body composition of young, female and male mice, exposed to cigarette smoke during adolescence as well as response to abstinence in adult life. From weaning, at 21 days post natal, until the end of the experimental period, animals were fed with normal (7S) and high-fat (19S) diets. From 35 to 50 days post natal, half of the animals were exposed to cigarette smoke (F) and the other half remained in ambient air (C). At the end, part of the animals was euthanized and the other remained in abstinence for 30 days (ABS). Food intake, body mass and body composition were all evaluated in all stages. Blood and visceral and subcutaneous adipose tissues were collected for analysis. In females, during smoke exposure, food intake was similar to C19S group and body mass gain was lower in F19S animals. In abstinence, F19S group presented the highest food intake and both F groups remained with reduced weight gain. Regarding body composition, the exposure determined higher lean mass, bone mineral density and bone area reduction, independent of diet, in addition to the tendence to lower abdominal fat deposits. After abstinence, the ABS7S and ABS19S groups maintained greater lean mass without alteration of bone mineral density, despite of the lower levels of mineral content and total bone area. ABS19S group had higher adipose deposits. The high-fat diet, during exposure, promoted increased glycemia and reduced beta cell function, with better indicators of abstinence, but high insulin resistance index remained. There was no change in plasma triglycerides and cholesterol. In males, smoke exposure reduced food intake, and this pattern was maintained after abstinence, with no difference in body mass gain, between C and F groups. Body composition and bone integrity showed similar pattern to that of females during exposure and abstinence, however, without reduction of bone area. There was a trend towards greater abdominal fat content, related to the type of diet. Insulin resistance indicators also responded in a similar way to females, with greater influence on the high-fat diet. Abstinence led to a reduction in cholesterol concentrations. Changes in food intake, body mass, body composition and glucose metabolism of males and females have occurred in different ways, showing that the effects of smoke sometimes overlap the influence of high-fat diet and not all are reversed with abstinence, remaining in adult life.