Definition of metabolic syndrome

LETTERS

Definition of metabolic syndrome

To the Editor:We read with interest the report by Chi et al comparing

and contrasting definitions of metabolic syndrome used inpediatric samples.1 However, we wish to qualify the charac-terization of our study in this article. Our study compared andcontrasted the prevalence of and demographic disparities inthe World Health Organization and National CholesterolEducation Panel (NCEP) Adult Treatment Panel III defini-tions of metabolic syndrome in adolescents in the PrincetonSchool District (PSD) Study.2 We did not create a “pediat-ric”-specific definition of metabolic syndrome. Instead, weextended the adult definitions to the adolescent age group.We felt this was important because there are discontinuitiesbetween the adult definitions and the various proposed pedi-atric definitions. For example, 14- to 18-year-old girls and18-year-old boys can meet the adult NCEP cutoff point forwaist circumference yet miss the 90% “pediatric” cutoffpoint.3 In addition, Table II indicates that our study popu-lation was NHANES, which is incorrect. Our data weredrawn from the PSD Study.

Chi et al specifically mention a “consensus clinical defini-tion.” We urge caution in clinically applying any of the proposeddefinitions to children of any age. There is continued debateabout the very existence of this syndrome. The evidence basedoes not support the use of metabolic syndrome in “risk profil-ing” among children or drug treatment in this age group. Amongadults with impaired glucose tolerance, metformin had no effecton prevalence of metabolic syndrome, whereas increased physicalactivity, which would be standard intervention for obesity,produced a significant decline.4 Both the American DiabetesAssociation and the American Heart Association agree that, inchildhood and adolescence, prevention and treatment of obe-sity and vigilant attention to the early diagnosis of diabetesmellitus are currently the most evidence-based methods for ad-dressing the clustering of cardiovascular risks metabolic syn-drome represents.5

Elizabeth Goodman, MDTufts-New England Medical Center and

the Floating Hospital for ChildrenBoston, MA

Stephen R. Daniels, MD, PhDDenver Children’s Hospital

Denver, CO

Lawrence M. Dolan, MDCincinnati Children’s Hospital Medical Center

Cincinnati, OH10.1016/j.jpeds.2006.11.057

REFERENCES1. Chi CH, Wang Y, Wilson DM, Robinson TN. Definition of metabolic syndromein preadolescent girls. J Pediatr 2006;148:788.2. Goodman E, Daniels SR, Morrison JA, Huang B, Dolan LM. Contrasting prev-alence of and demographic disparities in the World Health Organization and NationalCholesterol Education Program Adult Treatment Panel III definitions of metabolicsyndrome among adolescents. J Pediatr 2004;145:445-51.3. Fernandez JR, Redden DT, Pietrobelli A, Allison DB. Waist circumference per-centiles in nationally representative samples of African-American, European-American,and Mexican-American children and adolescents. J Pediatr 2004;145:439-44.4. Orchard TJ, Temprosa M, Goldberg R, Haffner S, Ratner R, Marcovina S, et al.The effect of metformin and intensive lifestyle intervention on the metabolic syndrome:the Diabetes Prevention Program randomized trial. Ann Intern Med 2005;142:611-9.5. Steinberger J, Daniels SR. Obesity, insulin resistance, diabetes, and cardiovascularrisk in children: an American Heart Association scientific statement from the Athero-sclerosis, Hypertension, and Obesity in the Young Committee (Council on Cardiovas-cular Disease in the Young) and the Diabetes Committee (Council on Nutrition,Physical Activity, and Metabolism). Circulation 2003;107:1448-53.

Reply

To the Editor:We appreciate the comments of Dr Goodman and her

colleagues. In response to their first comment, we apologizefor the error in Table II and acknowledge that their studypopulation was from the Cincinnati PSD, as cited in Table I.The data presented in their study used modified definitions ofthe adult metabolic syndrome (MS), specifically the ATP IIIand WHO criteria, to estimate prevalence of MS amongadolescents.1 Although Goodman et al did not create originalpediatric criteria for MS, they used “pediatric”-specific bodymass index percentiles for measurement of obesity rather thanestablished adult cutoff points for waist circumference. Sev-eral pediatric studies have validated body mass index as areliable method for predicting body fatness in children.2,3

However, as pointed out by Goodman et al, different sub-groups of obese children are identified with body mass indexversus waist circumference. This disagreement in classifica-tion causes concern from an epidemiological and clinicalstandpoint.

We recognize the limitations in applying a universaldefinition of MS in children. However, the purpose of choos-ing particular criteria and their cutoff points is to identify thehighest risk subset among obese children who may benefitfrom both lifestyle intervention and medical therapy. Currentstudies are now showing that “clustering” of multiple cardio-vascular risk factors can accelerate atherosclerosis in youngpeople.4 The Bogalusa Heart Study, a longitudinal community-based study of cardiovascular risk factors in children, revealed“tracking” of risk factor clustering related to MS from child-hood to adulthood, especially among obese subjects.5-10 Forinstance, when Bao et al studied 1176 individuals aged 5 to 17years during an 8-year period, they found that 61% of subjectswho were initially in the highest quintile of their multiple riskindex remained there 8 years later. Tracking of the multiple

e36 Letters The Journal of Pediatrics • April 2007