Adiposidade como fator de risco para doenças cardiovasculares em adolescentes do sexo feminino

• Autor(a) principal: Serrano, Hiara Miguel Stanciola
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2693
• topic: Obesidade em adolescentes; Nutrição; Doenças cardiovasculares; Dietoterapia; Composição corporal; Obesity in adolescents; Nutrition; Cardiovascular diseases; Dietotherapy; Body compostion; CNPQ::CIENCIAS DA SAUDE::NUTRICAO

In order to study the interference of body fat over risk factors of cardiovascular diseases in female adolescents from public schools in Viçosa-MG, a cross-sectional epidemiological study was carried out. In this study, 113 adolescents, whose age ranged from 14 to 18 years old, were evaluated and selected from public schools in Viçosa- MG, and the criteria to belong to one of the groups were: group 1 (G1) consisted of eutrophic subjects and with excess body fat; group 2 (G2): eutrophic subjects with body fat within normal limits; and group 3 (G3): overweight subjects with excess body fat. As for the selection, a sorting took place at their own school; the body fat percentage was detected through bipedal impedance and weight and stature were also checked. The adolescents who showed characteristics from the previously described groups received an end of consent to be signed by their parents or guardians. These adolescents were invited to go to the nutritional clinic from the Universidade Federal de Viçosa (UFV) Health Division for a new assessment of their body composition through horizontal bioelectrical impedance and using its own protocol. Then, weight, stature, waist and hip circumferences and blood pressure were assessed, as well as BMI and wait-to-hip ratio were calculated. Both body fat percentage and biochemical evaluations were performed after 12 hour fasting, and blood was collected for the sake of lipidic profile assessment (total cholesterol, LDL, HDL, VLDL, triglycerides), glycemia, insulin, homocysteine, leptin, and C- reactive protein. Insulin resistance was calculated through the HOMA index. The questionnaire on Frequency of Food Consumption (QFCA) was applied individually, consisting of food usually consumed by female adolescents in Viçosa, MG. These adolescents with excess body fat showed menarche in earlier ages. High prevalence of sedentary life style was found (79.64%) and group 1 was the one which showed higher percentage of sedentary adolescents (84.21%), followed by group 2 (77.5%) and group 3 (77.14%). A higher prevalence of not transmissible chronic diseases was identified among the excess body fat adolescents relatives, where obesity and high blood pressure were the most prevalent regardless the study group. Most of the adolescents had four or more than that daily meals and there was no statistical difference among the groups. Out of the three main meals, 23.89% of the adolescents skipped breakfast, and 11.5% skipped dinner. Among the most consumed foods by all the adolescents (or four times or more than that a week) are rice (99.09%), beans (93.63%), bread (83.48%), vegetables (76.36%), whole milk (70.88%), fruits (66.96%), sweets (68.51%), chocolate powder (55.34%), chewing gum (53.6%), fresh juice (49.05%), beef (48%), margarine (46.15%), and chicken (39.8%). Through a qualitative analysis of food consumption, it was possible to notice the frequency of fat-rich food and candies consumption. However, fruits and vegetables are among the most consumed foods with daily consumption of 66.94% and 75.45%, respectively, and there was no significant difference among the study groups. Only 11.5% of the adolescents didn t make use of milk. The usual consumption of olive oil was 15.9%. The consumption of pig lard, torresmo (food derived from pork) and bacon were low. Among the fat-rich foods, it was verified that 19.04% of the adolescents consume embedded food; 15.38% of them consume snacks and 27.35% of them consume savories. The habit of eating beef fat was of 43.36%, pork fat 30%, and chicken skin 54.86%. From the sweets group, the consumption of candies, chewing gum, lollipop, chocolate bar, and chocolate powder were highlighted. A negative correlation was found between these: vegetable consumption and diastolic blood pressure and total cholesterol; banana consumption and total cholesterol and LDL; carrot consumption and triglyceride levels; chicken and LDL, VLDL and triglycerides; candies and HDL levels. The snack consumption correlated positively with diastolic blood pressure, as well as margarine consumption and systolic blood pressure. Other positive correlations occurred between VLDL bread consumption and triglycerides; cheese, VLD and fresh juice and glycemia. Insulin resistance was detected in 20.35% of the adolescents, with statistical difference among the study groups: G1>G2 and G1<G3. The HOMA figures showed significant correlations with anthropometric variables the waist circumference was the one which had higher correlation. It was possible to check that 3.54% of the adolescents had high blood pressure, all of whom were overweight. The systolic and diastolic blood pressure levels were higher in those who had excess adiposity and both of them showed significant positive correlation with the HOMA index. More than half of the adolescents from this study showed at least one metabolic change, mainly changes in the lipidic profile, which occurred even in the eutrophic subjects. There was no significant statistical difference among the study groups concerning total cholesterol, LDL, VLDL and triglycerides. By analyzing the leptin levels, it was noticeable that there was a significant difference among the study groups: G1 > G2 and G1 < G3. The prevalence of hyperhomocysteinemia was of 3.54%, with no difference among the study groups. C-reactive protein was changed in 12.38% of the adolescents, with no statistical difference among the study groups; however, the adolescents who had higher percentage of body fat showed higher figures. The average and median were above the reference levels and more than half of the adolescents showed this change. Insulin resistance seemed to be the bond between obesity and metabolic changes. This connection, previously evidenced only among adults, can now be found in adolescents, with an aggravating, though not only in the overweight ones, but also in the eutrophic ones, regardless the body fat percentage. Thus, it s highly important that there are nutritional educational programs which aim at the maintenance not only of healthy weights, but of adiposity within normal levels as well in order to avoid the occurrence of metabolic and clinic changes throughout adolescence and more serious complications in the adulthood.