Importance of assessing all components of the metabolic syndrome in adolescents

LETTERS TO THE EDITOR

Importance of assessing all components of the metabolic syndrome in adolescents

Augusto César Ferreira de Moraes;^I Flavia Auler;^II Mário Cícero Falcão^III

^IProfessor especialista. Aluno, Programa de Pós-Graduação em Ciências, Faculdade de Medicina, Área: Pediatria, Universidade de São Paulo (USP), São Paulo, SP, Brazil. Membro, Grupo de Estudo e Pesquisa em Epidemiologia da Atividade Física (GEPEAF), Grupo de Estudo e Pesquisa em Metabolismo, Nutrição e Exercício (GEPEMENE) e Centro de Educação Física e Esporte da Universidade Estadual de Londrina (CEFE), Universidade Estadual de Londrina (UEL), Londrina, PR, Brazil

^IIMestre, nutricionista e professora, Curso de Nutrição, Pontifícia Universidade Católica do Paraná (PUCPR), Maringá, PR, Brazil

^IIIDoutor. Pediatra e Nutrólogo, Programa de Pós-Graduação em Ciências, Faculdade de Medicina, USP, São Paulo, SP, Brazil

The study carried out by Rodrigues et al.,¹ recently published in this respected journal, aimed to evaluate the occurrence of metabolic syndrome and the association between risk factors in adolescents. We read the article with interest, since prevalence studies on metabolic syndrome in this age group among Brazilians are scarce, as reported in a recent review.² However, we have observed some inaccurate results concerning metabolic syndrome components, misinterpretation or inadequacy of cited references, as well as inadequate statistical analysis to determine the association between risk factors.

In relation to components, the authors have not assessed the prevalence of abdominal obesity, which, according to the criterion recommended by the Brazilian Society of Cardiology,³ should be included in the criteria for diagnosis of the syndrome, based on the criteria of the National Cholesterol Education Program - Adult Treatment Panel III (NCEP-ATP III). On the other hand, this component is also quite controversial regarding cutoff points in adolescents, and Cook et al.⁴ adapted NCEP-ATP III criteria and proposed that abdominal obesity should be defined as values greater than or equal to the 90th percentile. Thus, we consider that abdominal obesity is an important component to be evaluated in the diagnosis of metabolic syndrome because it is directly related to increased blood pressure and changes in the lipid profile.⁵

We have analyzed the references cited by the authors and verified two primary inaccuracies. The first one occurred when the authors stated that "we adopted the values suggested and adjusted for this age group in another study."⁶ We have verified that this reference approaches only criteria for diagnosis of one of the components of the metabolic syndrome, blood pressure. For that purpose, we suggest that the authors, in future studies, use as diagnostic criteria the cutoff points adapted by Cook et al.,⁴ which have been widely accepted in the scientific community. The second aspect is concerned with the citation of the adopted criterion; after a search for the journal volume on Revista Brasileira de Hipertensão, we could not find the article as therein referenced.

At last, in the manuscript title, the authors propose an analysis of possible associations between risk factors and metabolic syndrome. However, we have not found these analyses in the results; we could only observe a description of the components, regarding continuous data and prevalence of each one of them according to sex. For that purpose, the literature shows some indicators of associations in cross-sectional studies,⁷ such as odds ratio and prevalence ratio, in which it is possible to analyze the probability of outcome occurrence according to the presence or absence of exposure.

In summary, we consider this study an important contribution to the scientific community, since it is one of the few investigations on Brazilian adolescents. We point out that our comments do not affect the value of this study and we do hope that we have contributed toward a better understanding of the data reported.

No conflicts of interest declared concerning the publication of this letter.

Author's reply

Anabel Nunes Rodrigues^I

^IDoutor. Professor, Centro Universitário do Espírito Santo (UNESC), Colatina, SC, Brazil

Dear Editor,

We want to thank the authors for the comments on our article. The authors explain that, at any moment, they have focused their concerns on the criteria to define metabolic syndrome, because if such definition does exist,¹ consensus criteria for diagnosis in adults do not exist,^2,3 neither do they in adolescents. In our article, our concern lay in demonstrating the presence of risk factors in a randomly selected sample and that these risk factors exist in such proportions that they can be grouped together, and, according to one of the several criteria suggested in the literature, based on pediatric reference values, they can give rise to the so-called metabolic syndrome. Therefore, we have not proposed an analysis of the associations between risk factors.

The authors believe that discussing criteria which have not reached consensus^2,3 leads to a shift in focus from the seriousness of the presence of isolated or associated risk factors at such an early life stage, and that a simple aggregate of such and such factor, in order to reach a diagnosis of metabolic syndrome, would mean admitting that the syndrome implies a higher risk than its components or that it is more severe than other risk factors for cardiovascular disease. For this reason, due to lack of scientific support, we do not concur with such conclusions. It is worth mentioning that some studies^4-6 have shown that risks attributed by the metabolic syndrome are not higher than the sum of its components, that is, the syndrome is not greater than the sum of its parts. Thus, all risk factors need to be fought individually, with no need for percentages of the syndrome for such and such criterion in order to enhance treatment, prescription and encouragement of healthy life habits.

Finally, the precursor of the idea of metabolic syndrome, Reaven,⁷ in a recent review, has questioned the syndrome: "metabolic syndrome – rest in peace."

No conflicts of interest declared concerning the publication of this letter.

References (Letter to the editor)

Referências (Resposta do autor)

• 1. Rodrigues AN, Perez AJ, Pires JG, Carletti L, de Araújo MT, Moyses MR, et al. Cardiovascular risk factors, their associations and presence of metabolic syndrome in adolescents. J Pediatr (Rio J). 2009;85:55-60.
• 2. Moraes AC, Fulaz CS, Netto-Oliveira, ER, Reichert FF. Prevalęncia de síndrome metabólica em adolescentes: uma revisăo sistemática. Cad Saude Publica. No prelo 2009.
• 3. Sociedade Brasileira de Cardiologia. I Diretriz brasileira de diagnóstico e tratamento da síndrome metabólica. Arq Bras Cardiol. 2005;84:1-28.
• 4. Cook S, Weitzman M, Auinger P, Nguyen M, Dietz WH. Prevalence of a metabolic syndrome phenotype in adolescents: findings from the third National Health and Nutrition Examination Survey, 1988-1994. Arch Pediatr Adolesc Med. 2003;157:821-7.
• 5. Giuliano IC, Coutinho MS, Freitas SF, Pires MM, Zunino JN, Ribeiro RQ. Lípides séricos em crianças e adolescentes de Florianópolis, SC Estudo Floripa Saudável 2040. Arq Bras Cardiol. 2005;85:85-91.
• 6. National High Blood Pressure Education Program, Working Group on High Blood Pressure in Children and Adolescents. The fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents. Pediatrics. 2004;114:555-76.
• 7. Francisco PM, Donalisio MR, Barros MB, Cesar CL, Carandina L, Goldbaum M. Medidas de associaçăo em estudo transversal com delineamento complexo: razăo de chances e razăo de prevalęncia. Rev Bras Epidemiol. 2008;11:347-55.
• 1. Saad MJ. Síndrome metabólica: vale a pena o diagnóstico? Rev Soc Cardiol Estado de Săo Paulo. 2008:18:108-13.
• 2. Lottenberg SA, Glezer A, Turatti LA. Metabolic syndrome: identifying the risk factors. J Pediatr (Rio J). 2007;83:S204-8.
• 3. Chen W, Berenson GS. Metabolic syndrome: definition and prevalence in children. J Pediatr (Rio J). 2007;83:1-2.
• 4. Alexander CM, Landsman PB, Teutsch SM, Haffner SM. NCEP-defined metabolic syndrome, diabetes, and prevalence of coronary heart disease among NHANES III participants age 50 years and older. Diabetes. 2003;52:1210-4.
• 5. Golden SH, Folsom AR, Coresh J, Sharrett AR, Szklo M, Brancati F. Risk factor groupings related to insulin resistance and their synergistic effects on subclinical atherosclerosis: the Atherosclerosis Risk in Communities Study. Diabetes. 2002; 51:3069-76.
• 6. McNeill AM, Rosamond WD, Girman CJ, Golden SH, Schmidt MI, East HE, et al. The metabolic syndrome and 11-year risk of incident cardiovascular disease in the atherosclerosis risk in communities study. Diabetes Care. 2005;28:385-90.
• 7. Reaven GM. The metabolic syndrome: requiescat in pace. Clin Chem. 2005;51:931-8.

Publication Dates

• Publication in this collection
  30 June 2009
• Date of issue
  June 2009