The stability of metabolic syndrome in children and adolescents

CONTEXT

Some studies suggest the presence of metabolic syndrome before adulthood may identify those at high risk for later cardiovascular morbidity, but there are few data examining the reliability of pediatric metabolic syndrome.

OBJECTIVE

To examine the short- and long-term stability of pediatric metabolic syndrome.

DESIGN

Metabolic syndrome was defined as having at least three of the following: waist circumference, blood pressure, and fasting serum triglycerides in the 90th or higher percentile for age/sex; high-density lipoprotein-cholesterol 10th or lower percentile for age/sex; and fasting serum glucose of at least 100 mg/dl. Short-term metabolic syndrome stability (repeated measurements within 60 d) was assessed in obese youth ages 6-17 yr. Long-term metabolic syndrome stability (repeated measurements more than 1.5 yr apart) was studied in 146 obese and nonobese children age 6-12 yr at baseline.

PATIENTS AND SETTING

Convenience samples of obese and nonobese youth ages 6-17 yr participating in research studies were collected at a clinical research hospital.

RESULTS

Short-term metabolic syndrome stability (repeat measurements performed 19.7 +/- 13.1 d apart) was assessed in 220 children. The diagnosis of metabolic syndrome was unstable in 31.6% of cases. At their short-term follow-up visit, incidence of metabolic syndrome among participants who did not have metabolic syndrome at baseline was 24%. In the long term (repeat measurements performed 5.6 +/- 1.9 yr apart), the diagnosis of metabolic syndrome was unstable in 45.5% of cases.

CONCLUSIONS

Cutoff-point-based definitions for pediatric metabolic syndrome have substantial instability in the short and long term. The value of making a cutoff-point-based diagnosis of metabolic syndrome during childhood or adolescence remains in question.

Insulin resistance, hyperinsulinemia, and energy intake in overweight children

OBJECTIVE

To examine the relationship between energy intake during a buffet meal and indexes of insulin dynamics in overweight children.

STUDY DESIGN

Ninety-five nondiabetic, overweight (body mass index > or = 95th percentile) children (age 10.3 +/- 1.4 years) selected lunch from a 9835-kcal buffet eaten ad libitum after an overnight fast. The associations between energy intake and measures of insulin dynamics, in the postabsorptive state and during a 2-hour hyperglycemic clamp, were determined. Covariates in the statistical model included race, sex, skeletal age, fat-free mass, fat mass, socioeconomic status, and number of foods in the buffet rated as acceptable.

RESULTS

Energy intake was positively associated with the fasting homeostasis model assessment for insulin resistance index (beta = 0.24, P = .042), fasting insulin/glucose ratio (beta = 0.24, P = .044), first-phase insulin (beta = 0.23, P = .032), and first-phase C-peptide (beta = 0.21, P = .046); energy intake was negatively associated with clamp-derived insulin sensitivity (beta = -0.29, P = .042). Each 10% decrease in clamp-derived insulin sensitivity predicted a 27-kcal greater energy intake.

CONCLUSIONS

Insulin resistance and hyperinsulinemia are associated with greater energy intake after an overnight fast in overweight children. These associations suggest mechanisms whereby insulin resistance may contribute to excessive weight gain in children.

Structure analysis of the Children's Eating Attitudes Test in overweight and at-risk for overweight children and adolescents

BACKGROUND

In school-based samples of children, the Children's Eating Attitudes Test (ChEAT) has a four-factor structure; however, previous studies have not examined its factor structure in samples restricted to overweight youth.

METHODS

The ChEAT was administered to 220 overweight (BMI>or=95th percentile) and 45 at-risk for overweight (BMI 85th-<95th percentile) children and adolescents. Factors were identified by a principal component analysis with varimax rotation. ChEAT factor scores of children with BMI>or=85th percentile were contrasted with those of 152 non-overweight (BMI 5th to <85th percentile) children and adolescents.

RESULTS

Factor analysis generated four subscales described as 'body/weight concern,' 'food preoccupation,' 'dieting,' and 'eating concern.' ChEAT total score, body/weight concern, and dieting subscale scores were positively related to BMI-Z and body fat mass (p's<.05). Compared to non-overweight children, overweight and at-risk for overweight children had higher ChEAT total (9.9+/-7.4 vs. 6.6+/-7.8, p<.001), body/weight concern (3.2+/-3.1 vs. 1.3+/-3.0, p<.001), and dieting (1.8+/-2.2 vs. .8+/-2.3, p<.001) subscale scores.

CONCLUSIONS

The previously elucidated factor structure of the ChEAT was primarily supported in a sample of overweight children. The emergence of separate body/weight concern and dieting subscales may relate to these children's experiences with attempted weight reduction.

Vision screening in central Iowa

This study assessed the vision-screening practices of all preschools and elementary schools during the spring of 2000 in the Heartland Area Education Agency (AEA) in central Iowa. Surveys were returned by 7% of the preschools and 56% of the elementary schools. Survey questions were drafted based on recommendations from the Iowa Vision Screening Program Guidelines, which were distributed to all Iowa school districts in 1997. Areas surveyed included vision-screening personnel, attainment of students' visual history, rescreening practices, referral and follow-up, and screening procedures. Survey results indicated that there is a need for improvement to standardize vision-screening procedures within Heartland AEA. Time and effort are invested in activities that are not recommended, and not enough effort is being put into recommended activities such as obtaining vision histories, rescreening to avoid overreferrals, and follow-up to make sure students receive required treatment.