Diagnostic criteria and risk factors for the metabolic syndrome in adolescents who have already shown menarche and attend public schools in Viçosa-MG
An epidemiological study with cross sectional was carried out to diagnose the metabolic syndrome and its possible risk factors in adolescents who have already shown menarche. The sample consisted of 100 adolescents at the age range from 14 to 17 years, who were selected at public schools in Viçosa- MG. The following were the inclusion criteria: to be studying at high school have already shown the menarche for at least one year. Four criteria proposed for diagnosis of the metabolic syndrome in adults (WHO, 1998; EGIR, 1999; NCEP/ATPIII, 2001; IDF, 2005) were compared, as well as a criterion proposed for adolescents (Alvarez et al., 2006). Because most criteria are addressed to adults, the evaluation of the risk markers for the metabolic syndrome was accomplished by adaptations for the age range under study. The body composition parameters (weight, stature, IMC and derived indexes (IMCG and IMCLG), percent fat, fat mass and fatless mass (MG and MLG), circumferences of both waist (CC) and hip (CQ) and waist/hip relationship (RCQ)), as well as the biochemical ones (total and cholesterol and fractions, triglyceride, glucemia, fast insulin and homocysteine) and clinical ones (both systolic and diastolic blood pressure). The determination of the insulin resistance was based on insulin levels and fast glucemia by HOMA-IR. The evaluation of the nutritional state was based on the Body Mass Index (BMI), by using the cut points preconized by CDC/NCHS (2000). The percent body fat was estimate by the horizontal electric bioimpedance device and was classified according to Lohman (1992). The cut points were used for the dyslipidemia classification, preconized by the III Diretrizes Brasileiras sobre Dislipidemias (2001) and I Diretriz de Prevenção da Aterosclerose na Infância e na Adolescência (2005). The levels of the fast insulin and the insulin resistance by HOMA-IR were classified according to the I Diretriz de Prevenção da Aterosclerose na Infância e na Adolescência (2005). For the altered fast glucemia, the recommendation by American Diabetes Association (2006) was used. The arterial hypertension was characterized according to V Diretrizes Brasileiras de Hipertensão Arterial (2006). Two tools for dietary evaluation were applied: Questionnaire of the Alimentary Consumption Frequency (QFCA) and Twenty-four hour Recordatory (R24H). From the dietary analysis data, the following variables were evaluated: energy, proteins, carbohydrates, lipids, iron, C vitamin, calcium, fibers, monounsaturated fatty acids (AGMI), polyunsaturated fatty acids (AGPI), saturated fatty acids (AGS) and cholesterol. In relation to nutritional state, 83, 11 and 6% showed eutrophia (ME), overweight / overweight risk (RS/SP) and low weight (BP) (CDC/NCHS, 2000), whereas 61% showed high percent body fat (% GC) high. The total cholesterol presented the highest percent inadequacy (57%), followed by HDL (50%), LDL (47%) and triacylglycerols (22%). Inadequacy was observed in 11, 9, 5 and 4% respectively, in relation to HOMA-IR, insulin, blood pressure and glucemia. The syndrome prevalence ranged from 1-28%, depending on the criteria and cut points. The criterion by WHO (1998) adapted to the age range showed higher positive predictive values, whereas the criterion including all the components used in the different proposals showed higher sensibility and specificity values. Higher levels were observed for insulin, to HOMA-IR and for most body composition variables in the adolescents with excessive weight or body fat. With the increased HOMA-IR quartiles, an increase also occurred in the weight, IMC, IMCG, CC, CQ, MG, MLG, central and peripheral fat, % GC, triglyceride, VLDL, CT/HDL and glucose. For total cholesterol, insulin, HOMA-IR and nutritional state, RS/SPgt;BP (p lt;0.05). For body composition and nutritional state, RS/SPgt;EUgt;BP (p lt;0.001). Positive and strong correlations were found between IMC and the anthropometric measures estimating the percent fat, as well as its central distribution, except for RCQ. The %GC was correlated to the insulin levels (r=0.303; p lt;0.001) and to HOMA-IR (r=0.281; p lt;0.001). Both energy and macronutrient intakes were inversely correlated with the body composition parameters. Only the fast glucemia levels showed positive correlation with energetic intake of both lipids and saturated fatty acids. Low fruit consumption were found, as 43% teenagers used to consume them daily, whereas the average fiber consumption was below the recommended one, and 18% showed a cholesterol intake above the recommended one. Those excessively weighty adolescents told to consume higher sugar amount. Intake of the saturated fatty acids were higher in the teenagers without metabolic syndrome. Despite to be not statistically significant, those adolescents with metabolic syndrome showed a tendency to lower intake of C vitamin, calcium, iron and fibers. The adolescents presented several metabolic alterations, as being most times related to both excessive weight and body fat and to the insulin resistance, which under association rather constitute the metabolic syndrome. The best criteria for the metabolic syndrome diagnosis in the population screening and clinic practice were, respectively, the criterion including all components used in different proposals and the one by WHO (1998) adapted to the age range. The high prevalence of those metabolic disturbances and the alimentary mistakes can endanger those adolescents' current and future health, therefore justifying the need for constant intervention in this population, towards reinforcing the importance of specific programs contemplating the adolescent's health.
Advisor:Maria do Carmo Gouveia Peluzio; Sylvia do Carmo Castro Franceschini; Silvia Eloiza Priore; Gilberto Paixão Rosado; Sônia Machado Rocha Ribeiro; Luciana Ferreira da Rocha Sant?Anna
School:Universidade Federal de Viçosa
Source Type:Master's Thesis
Date of Publication:07/30/2007