Environment and Obesity in the National Children\u27s Study

Objective: In this review we describe the approach taken by the National Children’s Study (NCS), a 21-year prospective study of 100,000 American children, to understanding the role of environmental factors in the development of obesity. Data sources and extraction: We review the literature with regard to the two core hypotheses in the NCS that relate to environmental origins of obesity and describe strategies that will be used to test each hypothesis. Data synthesis: Although it is clear that obesity in an individual results from an imbalance between energy intake and expenditure, control of the obesity epidemic will require understanding of factors in the modern built environment and chemical exposures that may have the capacity to disrupt the link between energy intake and expenditure. The NCS is the largest prospective birth cohort study ever undertaken in the United States that is explicitly designed to seek information on the environmental causes of pediatric disease. Conclusions: Through its embrace of the life-course approach to epidemiology, the NCS will be able to study the origins of obesity from preconception through late adolescence, including factors ranging from genetic inheritance to individual behaviors to the social, built, and natural environment and chemical exposures. It will have sufficient statistical power to examine interactions among these multiple influences, including gene–environment and gene–obesity interactions. A major secondary benefit will derive from the banking of specimens for future analysis

Canalization of Growth in Down Syndrome Children Three Months to Six Years

While growth of children with Down syndrome has been noted to be retarded, several studies have suggested that phenotypic development is also more poorly canalized. The present study compares the degree of canalization of growth in a group of Down syndrome and normal children 3 months to 6 years. Data for each sample are analyzed by longitudinal principal components analysis. The first component is a centile position component and the second component is a centile shift component. The remaining three retained components summarize deviations around the curve of growth described by the first two components. Using parameters based on the component scores from a joint analysis of the two groups, the Down syndrome group has significantly lower component scores for the first and second principal components indicating that, as documented in other studies, they are smaller and show markedly deficient growth velocity. The Down syndrome group show greater variability than the control group for the remaining components indicating a tendency to greater deviations around the curve of growth described by the first two components. This difference is interpreted as manifestation of poorer canalization of growth in the Down syndrome group

Changes in Triceps and Subscapular Skinfold Thickness During Adolescence

Investigations of adolescent changes in subcutaneous fat have consistently shown gain and then loss in subcutaneous fat at the triceps site in boys. Results concerning changes at triceps for girls and trunk sites in both sexes differ among studies, some showing increasing values across age, others showing the pattern typical of male triceps skinfold thickness. The present study reports results concerning serial skin­fold measurements of triceps and subscapular skinfold thickness in a sample of approximately 59 individuals (29 boys and 30 girls) participating in the Fels Longitudinal Study. All data are reported relative to age at peak height velocity (APHV) to correct for individual differences in maturation. Triceps skinfold in boys shows the expected pattern of increase and decrease. Changes at both boys’ and girls’ subscapular sites are small except at the 90th percentile where an increase followed by a decrease is evident. In girls, values for triceps skinfold increase slightly and then decrease except at the 90th percentile. Mean increments relative to APHV are similar at both sites in each sex and indicate a correspondence in the occurrence and magnitude of fat gains and losses at each site, particularly near APHV. These findings suggest that patterns of fat gain and loss do occur at triceps and subscapular skinfold sites in both sexes, though this pattern may not occur in all individuals

Relationship of Fetal Ultrasound Measurements to Postnatal Anthropometric Variables and Maternal Measurements

Understanding of the continuity of fetal with postnatal growth and the heritability of fetal size has been based largely on studies of birth size. Because intrauterine influences may be greater near birth, birth size may be a poor representative of growth earlier in fetal life. This paper presents correlations between ultrasound dimensions measured twice during fetal life between 13 and 36 weeks of gestation and analogous anthropometric variables measured twice postnatally between 6 and 16 months on the same individuals (n=51). Measurements taken during these age intervals should be free of the most intensified intrauterine influences operating near birth. Shared variance between the two periods (about 10-35%) is significant but substantially lower than variance shared between measurements taken within each period (36 to 90%). Correlations between the repeated fetal measurements are lower than those between postnatal dimensions (0.6 versus 0.9). Maternal linear and cranial dimensions have higher associations with postnatal than with fetal measurements, while measures of maternal prepregnancy body fatness are negatively associated with fetal cranial dimensions. Birth weight has similar correlations with fetal and postnatal measurements (between 0.3 and 0.5). However, birth weight explains significant variance for fetal cranial dimensions but not fetal femur length. These findings indicate that significant variance in fetal size is shared with postnatal size. Greater continuity is apparent for linear (femur length and recumbent length) than for cranial dimensions. This suggests that intrauterine influences may have more intense effects on cranial than on linear growth

The Wisconsin Fetal Alcohol Syndrome Screening Project

Problem: Fetal Alcohol Syndrome (FAS) is preventable, under-diagnosed, and under-reported. Wisconsin rates for alcohol use and binge drinking in childbearing-age women exceed the national average. FAS prevalence in Wisconsin has not previously been systematically evaluated. Methods: The Wisconsin Fetal Alcohol Syndrome Screening Project (WFASSP) used a multi-stage, multi-source prospective population-based screening meth-odology to identify children born in 1998-1999 in Southeast Wisconsin who met a surveillance case definition for FAS. The 4-stage methodology used screening of electronic birth files, abstraction of neonatal medical records, and direct assessment of facial features, growth, and development at age 2 to 3 years. Results: The FAS prevalence rate was 0.23 per 1000 births. Children directly evaluated had fewer demographic, pregnancy, and maternal substance use risk factors than lost-to-follow-up children. Thirty-two percent of children with weight and head circumference below the 10th percentile at birth were developmentally delayed and 47% had at least one physical growth delay. Conclusions: The WFASSP methodology identified children who had not previously been diagnosed with FAS. Using the combination of weight and head circumference below the 10th percentile at birth is a useful methodology for identifying children at substantial risk for growth and developmental delays from FAS or other unspecified etiologies

Longitudinal Trends of Weight/Stature2 in Childhood in Relationship to Adulthood Body Fat Measures

The degree of continuity from childhood to adulthood in body fatness is evaluated using the results of longitudinal principal components analysis of W/S2 during childhood (3 months-18 years) in relation to several adult measures of body fatness (W/S2 at 30 years, total body fat, per cent body fat, fat cell number, fat cell size, and weight change from 18 to 30 years). Sixty per cent or less of the variance in any of the adult outcomes is explained by trends in W/S2 during childhood represented by the components. The largest amounts of variance are explained for W/S2 at 30 years, total body fat and per cent body fat. Ten to fifteen per cent of the variance in fat cell number is explained by the components. Weight change between from 18-30 years and fat cell size are not significantly associated with trends in W/S2 during childhood. These results suggest that a significant proportion of the variance in adulthood body fatness is determined by influences beginning after maturity is reached

Longitudinal Trends and Continuity in Weight/Stature2 from 3 Months to 18 Years

Longitudinal principal components analysis is used to summarize childhood trends in one measure of body fatness (W/S2) using pooled data from several large American longitudinal growth studies. For each of the age intervals analyzed (3 months-3 years, 3-9 years, 10-17 years and 4-18 years), component one represents magnitude or percentile level of W/S2 and component two represents change in percentile level of W/S2 from the beginning to the end of the age period. Components three through six represent more complicated patterns of change in W/S2 where percen­tile position fluctuates several times during the age interval analyzed. Information about continuity in W/S2 within and between the various age intervals can be discerned from the number of components retained and by correlations between component one scores from each of the age intervals. Intra-individual variation appears to be greater during infancy and adolescence than during childhood, and degree of continuity is greater between childhood and adolescence than between infancy and childhood. On the basis of both the number of components retained in the analyses of each age interval and the size of the correlations between component one scores for analyses at different age intervals, females appear to have a greater degree of continuity in W/S2 during childhood and adolescence than males

The National Children\u27s Study, Waukesha Country, Wisconsin, Vanguard Center

The National Children\u27s Study (NCS) is a large, long-term study designed to detect environmental influences on the health and development of children. Waukesha County, Wisconsin, was selected as 1 of 7 Vanguard Centers currently funded to finalize and lead the implementation of the study protocol. The authors provide an overview of key design and planning processes that will be used at all NCS Vanguard locations, the specific approaches to be used in the NCS Waukesha Country Vanguard Center, and information about Wisconsin physicians and other health care professionals can become involved in working with the NCS