Background-Metabolic syndrome (MetS) is defined by the Third Report of the Adult Treatment Panel (ATP III) using criteria easily applied by clinicians and researchers. There is no standard pediatric definition. Methods and Results-We defined pediatric MetS using criteria analogous to ATP III as Ն3 of the following: (1) fasting triglycerides Ն1.1 mmol/L (100 mg/dL); (2) HDL Ͻ1.3 mmol/L (50 mg/dL), except in boys aged 15 to 19 years, in whom the cutpoint was Ͻ1.2 mmol/L (45 mg/dL); (3) fasting glucose Ն6.1 mmol/L (110 mg/dL); (4) waist circumference Ͼ75th percentile for age and gender; and (5) The MetS has not been well characterized in children and adolescents in terms of criteria, prevalence, or clinical implications, although studies have examined MetS abnormalities. 5,6 We propose a definition of MetS in adolescents based closely on the ATP III 1 and, using NHANES III data, describe its prevalence in US children aged 12 to 19 years. MethodsATP III defines adult MetS as 3 or more of the criteria described in the Table. To generate a definition appropriate for children aged 12 to 19 years, we extrapolated from adult criteria. Triglyceride (TG) and HDL cutpoints were taken from equivalent pediatric percentiles. 7 We defined hyperglycemia using the ATP III cutpoint. ATP III uses waist circumference as a measure of central obesity, and percentiles for age and gender have been most associated with central obesity in children across genders and races 8 ; therefore, we used percentiles comparable to the adult male cutpoint of the 70th percentile. 9 Because normal pediatric blood pressure varies significantly, we used the National Heart, Lung, and Blood Institute's recommended cutpoint of Ͼ90th percentile for age, gender, and height. 10 NHANES III is a national data set collected between 1988 and 1994, weighted to represent the population of noninstitutionalized US civilians not living on Indian reservations and aged 2 years and Statistical MethodsFor the 1960 children aged 12 to 19 years who participated in the examination of the NHANES III survey and fasted for at least 8 hours, the prevalence of MetS was calculated overall and by gender, age group, and race or ethnicity. Because of the survey's complex sampling design, estimates and standard errors were calculated in Stata 12 with the sampling weights provided, to be representative of the civilian, noninstitutionalized US population. Sample weights are adjusted for nonresponse. For estimates of prevalence, subjects with missing information on MetS criteria were assumed not to have met that criterion. A second set of estimates was calculated solely for subjects with nonmissing data for all 5 criteria. MetS prevalence was also estimated in the subgroup of adolescents with body mass index Ն85th percentile for age and gender. ResultsLow HDL, hypertriglyceridemia, and central obesity were common among the present sample, whereas hyperglycemia and hypertension were infrequent ( Figure 1). As in adults, hypertriglyceridemia and low HDL were most common among non-Hispani...

Treatment of patients with ␤-thalassemia major has improved dramatically during the past 40 years; however, the current clinical status of these patients remains poorly characterized. We performed a cross-sectional study of 342 patients in the Registry of the National Institutes of Health-sponsored Thalassemia Clinical Research Network. Evidence of hepatitis C exposure was present in 35% of tested patients, was associated with age, and had a rate of spontaneous viral clearance of 33%. Ferritin levels ranged from 147 to 11 010 ng/mL (median, 1696 ng/mL). Median hepatic iron content was 7.8 mg/g dry weight and 23% of patients had values of 15 mg/g dry weight or higher. No patients 15 years or younger and 5% of patients aged 16 to 24 years had heart disease requiring medication. Ten percent had cirrhosis on biopsy. Endocrinologic complications were common among adults. Seventy-four (22%) patients had recent implantable central venous access devices (CVADs) placed. Among 80 episodes of bacteremia in 38 patients, 90%were attributable to the CVAD. Among 330 patients who had received deferoxamine chelation therapy, 224 (68%) reported no complications. We conclude that hepatitis C, iron-related organ dysfunction, and complications of iron chelation therapy are strongly age-dependent in North American patients with ␤-thalassemia.

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