Non-high-density lipoprotein cholesterol concentration is associated with the metabolic syndrome among US youth aged 12-19 years.

OBJECTIVE: To test the hypothesis that the concentration of non-high-density lipoprotein cholesterol (non-HDL-C) is associated with the metabolic syndrome (MetS) in youth. STUDY DESIGN: Data on children and adolescents aged 12-19 years (n = 2734) from the cross-sectional National Health and Nutrition Examination Survey 1999-2004 were analyzed. RESULTS: Depending on the definition of MetS used, the mean non-HDL-C concentration among youth with MetS ranged from 144.2 to 155.8 mg/dL, compared with 108.8-109.1 mg/dL in those without MetS (all P < .001). The MetS prevalence ranged from 6.9% to 11.7% in youth with a non-HDL-C concentration of 120-144 mg/dL and from 21.5% to 23.4% in those with a concentration ≥ 145 mg/dL-both significantly higher than the prevalence of 1.9%-3.4% in youth with a concentration <120 mg/dL (all P < .001). After adjustment for potential confounders, youth with a non-HDL-C concentration ≥ 120 mg/dL or ≥ 145 mg/dL were about 3 or 4 times more likely to have MetS compared with those with a non-HDL-C <120 mg/dL or <145 mg/dL (all P < .001). CONCLUSIONS: Fasting non-HDL-C concentration was strongly associated with MetS in US youth. Our results support the use of non-HDL-C thresholds of 120 mg/dL and 145 mg/dL to indicate borderline and high MetS risk, respectively.

The prevalence and correlates of taking folic acid and vitamin supplements among adults aged ≥ 45 years with CVD.

OBJECTIVE: To examine the prevalence and likelihood of taking folic acid or vitamin supplements among adults with CHD or stroke v. adults without these conditions. DESIGN: A cross-sectional Behavioural Risk Factor Surveillance System survey was conducted in twelve states of the United States and Puerto Rico in 2006. Self-reported data from participants were collected. SETTING: The United States. SUBJECTS: US non-institutionalised adults (n 41 792), aged ≥ 45 years. RESULTS: Of all participants, 5445 had CHD and 2076 had stroke. Significantly higher percentages of women than men reported taking folic acid or vitamin supplements. After adjustment for potential confounders, women with CHD had a significantly lower adjusted prevalence (AP) and adjusted OR (AOR) than women without CHD for taking folic acid less than one time per d (AP = 3·9 % v. 5·5 %; AOR = 0·56; 95 % CI 0·39, 0·81), for taking folic acid one to four times per d (AP = 50·0 % v. 57·5 %; AOR = 0·68; 95 % CI 0·60, 0·79), and for taking vitamin supplements (AP = 60·9 % v. 69·9 %; AOR = 0·66; 95 % CI 0·57, 0·76). Men with CHD had a significantly higher AP (50·4 % v. 46·2 %) and AOR (1·17; 95 % CI 1·02, 1·33) of taking folic acid one to four times per d than men without CHD. In both sexes, adults with stroke were as likely as those without to take these supplements. CONCLUSIONS: Substantial variations in the prevalence and likelihood of taking folic acid or vitamin supplements exist by gender and by CHD status, but not by stroke status.

Stability of the factor structure of the metabolic syndrome across pubertal development: confirmatory factor analyses of three alternative models.

OBJECTIVE: To test the fit and stability of 3 alternative models of the metabolic syndrome's factor structure across 3 developmental stages. STUDY DESIGN: With data from the Fels Longitudinal Study, confirmatory factor analyses tested 3 alternative models of the factor structure underlying relationships among 8 metabolic syndrome-associated risks. Models tested were a 1-factor model (A), a 4-factor model (B), and a second-order latent factor model (C). Developmental stages assessed were prepuberty (ages 8-10), puberty (ages 11-15), and postpuberty (ages 16-20). RESULTS: Convergence was achieved for all developmental stages for model A, but the fit was poor throughout (root mean square error of approximation > 0.1). Standardized factor loadings for waist circumference and body mass index were much stronger than those for fasting insulin at all 3 time points. Although prepuberty and postpuberty models converged for models B and C, each model had problems with Heywood cases. The puberty model did not converge for either model B or C. CONCLUSIONS: The hypothetical structures commonly used to support the metabolic syndrome concept do not provide adequate fit in a pediatric sample and may be variable by maturation stage. A components-based approach to cardiovascular risk reduction, with emphasis on obesity prevention and control, may be a more appropriate clinical strategy for children and youth than a syndromic approach.

Patterns of change in cardiometabolic risk factors associated with the metabolic syndrome among children and adolescents: the Fels Longitudinal Study.

OBJECTIVES: To examine the patterns of change in cardiometabolic risk factors associated with the metabolic syndrome in children and adolescents between the ages of 8 to 19 years. STUDY DESIGN: Data of children and adolescents who participated in the Fels Longitudinal Study were analyzed. Body mass index, waist circumference, fasting insulin, fasting glucose, triglycerides, high-density lipoprotein cholesterol, systolic blood pressure, and diastolic blood pressure were assessed annually with a standardized protocol. RESULTS: The proportion of participants having at least 1 change between states of high and normal risk ranged from of 11.0% for body mass index to 30.4% for triglycerides. Youth in the high-risk category at baseline had a higher proportion having changed their status for all risk factors (all P < .05) except waist circumference compared with those in the normal-risk category. There were significant time effects for all risk factors (all P < .01) except fasting glucose and triglyceride levels in metric scores, but insignificant time effects for all risk factors in Z-scores in growth curve analyses. CONCLUSIONS: The cardiometabolic risk factors associated with the MetS were relatively stable among white children and adolescents in the normal risk category. Changes in status were common if the risk factor was elevated.

Defining the metabolic syndrome in children and adolescents: will the real definition please stand up?

OBJECTIVES: To review the use of definitions of the metabolic syndrome in studies of children and adolescents and to review results from studies that used factor analysis to examine structure among cardiometabolic variables. STUDY DESIGN: Literature review. RESULTS: In 27 publications, authors used 40 unique definitions of the metabolic syndrome. Most of these definitions were adaptations of the adult definition developed by the National Cholesterol Education Program. In 11 studies that used exploratory factor analysis, the number of components ranged from 5 to 19, and the number of factors identified ranged from 1 to 5. CONCLUSIONS: The use of multiple definitions of the metabolic syndrome argues strongly for the development of a standard pediatric definition.

Metabolic syndrome rates in United States adolescents, from the National Health and Nutrition Examination Survey, 1999-2002.

OBJECTIVE: To report the prevalence rates of the metabolic syndrome in a nationally representative sample of adolescents in the United States using 4 previously reported definitions of the syndrome. STUDY DESIGN: Data from 12- to 19-year-old adolescents included in the National Health and Nutrition Examination Survey from 1999 to 2002 (NHANES 99-02) were analyzed by cross-sectional methods, by using 4 definitions of the metabolic syndrome previously applied to adolescents. RESULTS: In NHANES 99-02, the prevalence of the metabolic syndrome in all teens varied from 2.0% to 9.4% of teens in the United States, depending on the definition used. In obese teens, these prevalence rates varied from 12.4% to 44.2%. In the group of obese teens, application of the definition by Cruz produced a metabolic syndrome prevalence rate of 12.4%; that of Caprio produced a rate of 14.1%. However, none of the normal weight or overweight teens met either definition. Application of the definition by Cook produced a prevalence rate of 7.8% in overweight teens and 44% in obese teens. The adult definition of metabolic syndrome produced a prevalence rate of 16% in overweight teens and 26% in obese teens. CONCLUSIONS: In the period between 1999 and 2002, the prevalence rate of metabolic syndrome varied from just >9% to as low as 2% of adolescents overall. Different definitions of metabolic syndrome generated prevalence rates in obese adolescents that varied widely from 12% to 44%. For this syndrome to be a useful construct, a more standardized set of criteria may be needed.

Longitudinal influence of mother's child-feeding practices on adiposity in children.

OBJECTIVE: Parental child-feeding practices are potentially significant determinants of body weight in youth. To date, research has focused on white middle class mother-child dyads. This study examines the longitudinal influences of child-feeding practices with time on total fat mass in white and African American boys and girls. STUDY DESIGN: Seventy-four white children (49 girls, 25 boys) and 47 African American children (25 girls, 22 boys; mean age at baseline, 11.0 years) and their mothers participated in this study. Child-feeding practices were measured with the Child Feeding Questionnaire. Total fat mass was measured by means of Dual energy X-ray absorptiometry on a yearly basis. The average follow-up period was 2.7 years. RESULTS: Pressure to eat and concern for the child's weight in white participants and restriction and concern for the child's weight in African American participants were significantly related to total fat mass at baseline. Concern for the child's weight was negatively related to the change of total fat mass with time in white participants. No longitudinal effects of child feeding practices on the change of total fat mass were found in African American participants. CONCLUSION: Parental concern for weight is a predictor of change in total fat mass with time in white children, but not African American children.