Validity of maternal recall of preschool diet after 43 years.

Validation of early childhood diet recalls by surrogate responders decades later has not been possible because of a lack of diet records from the distant past. Between 1948 and 1970, parents of children participating in the Fels Longitudinal Study (Kettering, Ohio) completed a 7-day diet record for their children every year from birth to age 18 years. In 2005-2006, all surviving women (n = 59) with a child aged 3-5 years when diet records had been collected were asked to complete a 42-item food frequency questionnaire (FFQ) pertaining to 1 of their children's diets at age 3-5 years. One or more diet records were available for 48 children. The authors calculated Spearman correlation coefficients for correlations between food, food-group, and nutrient intakes from the diet records and the FFQ and deattenuated them to account for the effects of within-person variation in the diet records on the association. For foods, the median deattenuated correlation coefficient was 0.19 (range, -0.31 to 0.85); moderate-to-high correlations were found for some specific foods. Correlations for food groups were slightly higher (median, 0.27; range, -0.14 to 0.85). Correlations for nutrient intakes were consistently low (median, 0.06; range, -0.35 to 0.27). Overall, the FFQ did not validly reflect overall preschool diet when completed by mothers 4 decades later.

Relations between frame size and body composition and bone mineral status.

BACKGROUND: Frame size is a description of the supportive structure of the skeleton that is used to adjust for skeletal mass and size in measures of body composition and weight. OBJECTIVE: Data from the Fels Longitudinal Study were used to investigate the relation between bicristal, elbow, knee, biacromial, and wrist breadths and measures of total body fat (TBF), fat-free mass (FFM), bone mineral content (BMC), and bone mineral density (BMD) from dual-energy X-ray absorptiometry. DESIGN: The sample consisted of cross-sectional data from 224 white men and 277 white women aged 23-65 y. Multiple regressions were conducted with stature-adjusted measures of body composition and bone mineral status as dependent variables and age and frame size as independent variables. RESULTS: Frame-size measures were significantly and positively associated with all body-composition and bone mineral measures in bivariate analyses. In both men and women, the significant models explained more of the variance in measures of TBF (R2 = 0.51 and 0.66, respectively) and FFM (R2 = 0.35 and 0.39, respectively) than in measures of BMC (R2 = 0.18 and 0.23, respectively) and BMD (R2 = 0.08 and 0.18, respectively). Bicristal, knee, and wrist breadths were associated with TBF, and biacromial, knee, and wrist breadths were positively associated with FFM. Biacromial breadth was positively associated with BMC and BMD. CONCLUSIONS: Frame size was more closely associated with TBF and FFM than with BMC and BMD. The association between frame size and body composition seems to be more structural than substantive. The relations between frame size and BMC and BMD are weak and apparently not related to body composition.

Predicting overweight and obesity in adulthood from body mass index values in childhood and adolescence.

BACKGROUND: The Centers for Disease Control and Prevention (CDC) introduced the clinical use of the body mass index (BMI; in kg/m(2)) in growth charts for young males and females. OBJECTIVE: This study updates our previous report with the use of new CDC BMI charts and definitions of adult overweight and obesity to predict adult overweight or obesity. DESIGN: Logistic models were fitted to relate adult overweight and obesity to childhood and adolescent BMI values at each age for 166 males and 181 females in the Fels Longitudinal Study and were applied to predict adult overweight and obesity at the 75th, 85th, and 95th percentiles on the CDC charts of childhood and adolescent BMI. RESULTS: A child or adolescent with a high BMI percentile on the CDC BMI-for-age growth charts has a high risk of being overweight or obese at 35 y of age, and this risk increases with age. For example, the probability of adult obesity at the 85th percentile for young males was

Changes in anthropometric indices of body composition with age in a healthy elderly population.

Changes in body composition are known to occur with old age, but there is limited knowledge of the normal values rates of change in anthropometric indices of body composition or the distribution of these changes in the elderly. In the present study, 98 elderly white men and 122 elderly white women were followed prospectively for 6 years. These participants were divided into 5-years cohorts on the basis of age at the start of the study in 1980. Separate linear regressions of triceps skinfold thickness, midarm circumference, midarm muscle area, and weight divided by stature squared on age were computed for each participant. The mean annual changes or slopes for these indices were small for each sex. A loss of subcutaneous adipose tissue was indicated with age, but the effects of compression or measurement error may hamper the detection of changes in indices of body composition in the elderly.

Genetic architecture of knee radiographic joint space in healthy young adults.

Evidence of a significant genetic component to the age-related degenerative joint disease osteoarthritis has been established, but the nature of genetic influences on normal joint morphology in healthy individuals remains unclear. Following up on our previous findings on the influence of body habitus on phenotypic variation in knee joint space [Duren et al., Human Biology 78:353-364 (2006)], the objective of the current study was to estimate the heritability of radiographic joint space in the knees of healthy young adults from a community-based sample of families. A sample of 253 subjects (mean age = 18.02 years) from 87 randomly ascertained nuclear and extended families was examined. Joint width (JW) and minimum joint space in the medial (MJS) and lateral (LJS) knee compartments were measured. A maximum-likelihood variance components method was used to estimate the heritability of MJS, LJS, and JW. Covariate effects of age, sex, age-by-sex interactions, stature, weight, and BMI were simultaneously estimated. Genetic correlation analyses were then conducted to examine relationships between trait pairs. MJS, LJS, and JW were each significantly heritable (p < 0.001), with heritabilities of 0.52, 0.53, and 0.63, respectively. The genetic correlation between MJS and LJS was not significantly different from 1. Genetic correlations between each joint space measure and JW were not significantly different from 0. This study demonstrates a significant genetic component to radiographic knee joint space during young adulthood in healthy subjects. This suggests that there are specific but as yet unidentified genes that influence the morphology of healthy articular cartilage, the target tissue of osteoarthritis. Genetic correlation analyses indicate complete pleiotropy between MJS and LJS but genetic independence of joint space and JW.

Presentation, heritability, and genome-wide linkage analysis of the midchildhood growth spurt in healthy children from the Fels Longitudinal Study.

Growth is a complex process composed of distinct phases over the course of childhood. Although the pubertal growth spurt has received the most attention from auxologists and pediatricians, the midchildhood growth spurt has been less well studied. The midchildhood growth spurt refers to a relatively small increase in growth velocity observed in some, but not necessarily all, children in early to middle childhood. If present, the midchildhood growth spurt typically occurs sometime between the ages of 4 and 8 years, well before the onset of the far more pronounced pubertal growth spurt. In this study we used a triple logistic curve-fitting method to fit individual growth curves to serial stature data from 579 healthy participants in the Fels Longitudinal Study, 479 of whom have been genotyped for about 400 short tandem repeat (STR) markers spanning the genome. We categorized individuals according to the presence or absence of a midchildhood growth spurt and then conducted heritability and genome-wide linkage analyses on the dichotomous trait. In the total sample of 579 individuals, 336 (58%) were found to have evidence of having had a midchildhood growth spurt. There was a marked sex difference in presence of the midchildhood growth spurt, however, with 232 of the 293 males (79%) having had a midchildhood growth spurt but just 104 of the 286 females (36%) having had one. Presence of a midchildhood growth spurt was found to have a significant heritability of 0.37 +/- 0.14 (p = 0.003). Two quantitative trait loci with suggestive LOD scores were found: one at 12 cM on chromosome 17p13.2 (LOD = 2.13) between markers D17S831 and D17S938 and one at 85 cM on chromosome 12q14 (LOD = 2.06) between markers D12S83 and D12S326.

Concordant and discordant sexual maturation among U.S. children in relation to body weight and BMI.

PURPOSE: This study investigates the extent to which discordant Tanner stages for sexual maturity indicators are associated with weight and body mass index (BMI) and their variation during adolescence. Discordant children with large differences in weight and BMI may require additional monitoring of their growth during adolescence. METHODS: Weight, BMI and Tanner stages, pubic hair in each gender, breast development in girls and genital development in boys, from 2103 boys and 2104 girls aged 8-18 years (average age 13.34 years) from the National Health and Nutrition Examination Survey III (NHANES III, 1988-1994) were analyzed. These cross-sectional data were grouped as concordant: assessed stages for paired indicators were equivalent, or as discordant: assessed stage for one paired indicator was greater or less than the other by one or more stages. Weight and BMI were compared separately by gender and race between concordant and discordant groups using analysis of covariance adjusted for age. RESULTS: Approximately 65-69% of all children were concordant, genital stage equaled pubic hair stage for boys and breast stage equaled pubic hair stage for girls. For all three racial groups, boys whose genital stage was more advanced than their pubic hair stage had significantly smaller weight and BMI (p<.05) than either concordant boys or boys whose pubic hair stage was more advanced than their genital stage. For all three racial groups, girls whose breast stage was more advanced than their pubic hair stage had significantly greater weight and BMI than girls whose pubic hair stage was more advanced than breast stage. Non-Hispanic black and Mexican-American girls whose breast stage was more advanced than their pubic hair stage had significantly greater weight and BMI that the respective concordant girls. CONCLUSION: Substantial and significant differences occur in weight and BMI among discordant and concordant children, and these differences are larger than between early and late maturing children.

Is sexual maturity occurring earlier among U.S. children?

PURPOSE: To compare the onset and completion of sexual maturation among U.S. children between 1966 and 1994. METHODS: Tanner stages were from 3042 non-Hispanic white boys, 478 black boys, 2625 white girls, and 505 black girls (NHES 1966-70), from 717 Mexican-American boys and 712 Mexican-American girls (HHANES 1982-84) and from 259 non-Hispanic white boys, 411 black boys, 291 white girls, 415 black girls, 576 Mexican-American boys and 512 Mexican-American girls (NHANES III 1988-1994). Proportions of entry into a stage, probit analysis estimated medians and selected percentiles for ages at entry were calculated using SUDAAN. RESULTS: NHANES III (1988-1994) non-Hispanic white boys entered stage 2, 3, and 4 genital development and stages 3 and 4 pubic hair earlier than NHES (1966-1970) white boys, but they entered stage 5 genital development significantly later. NHANES III (1988-1994) Mexican-American boys were in stage 2, 3 and 4 genital development earlier than HHANES (1982-1984) boys, but entry into stage 5 genital and pubic hair development was not significant. NHANES III (1988-1994) white girls entered stage 5 pubic hair later than NHES (1966-1970) white girls. NHANES III (1988-1994) Mexican-American girls entered stage 2 breast and pubic hair development earlier than HHANES (1982-1984) girls, entered stage 4 breast and pubic hair development earlier but entered stage 5 pubic hair later than the HHANES (1982-1984) girls. CONCLUSION: Persuasive evidence of a secular trend toward early maturation is not found between 1966 and 1994 in non-Hispanic black boys and non-Hispanic black and white girls. Some evidence of this trend is found in non-Hispanic white boys between 1966 and 1994 and in Mexican-American boys and girls between 1982 and 1994.

National estimates of the timing of sexual maturation and racial differences among US children.

OBJECTIVE: To provide clinically meaningful, normative reference data that describe the timing of sexual maturity indicators among a national sample of US children and to determine the degree of racial/ethnic differences in these estimates for each maturity indicator. METHODS: Tanner staging assessment of sexual maturity indicators was recorded from 4263 non-Hispanic white, black, and Mexican American girls and boys aged 8.00 to 19.00 years as part of the Third National Health and Nutrition Examination Survey (NHANES III) conducted between 1988 and 1994. NHANES III followed a complex, stratified, multistage probability cluster design. SUDAAN was used to calculate the mean age and standard error for each maturity stage and the proportion of entry into a maturity stage and to incorporate the sampling weight and design effects of the NHANES III complex sampling design. Probit analysis and median age at entry into a maturity stage and its fiducial limits were calculated using SAS 8.2. RESULTS: Reference data for age at entry for maturity stages are presented in tabular and graphical format. Non-Hispanic black girls had an earlier sexual development for pubic hair and breast development either by median age at entry for a stage or for the mean age for a stage than Mexican American or non-Hispanic white girls. There were few to no significant differences between the Mexican American and non-Hispanic white girls. Non-Hispanic black boys also had earlier median and mean ages for sexual maturity stages than the non-Hispanic white and Mexican American boys. CONCLUSION: Non-Hispanic black girls and boys mature early, but US children completed their sexual development at approximately the same ages. The present reference data for the timing of sexual maturation are recommended for the interpretation of assessments of sexual maturity in US children.

Puberty and body composition.

Body composition during puberty is a marker of metabolic changes that occur during this period of growth and maturation, and, thus, holds key information regarding current and future health. During puberty, the main components of body composition (total body fat, lean body mass, bone mineral content) all increase, but considerable sexual dimorphism exists. Methods for measuring body composition (e.g. densitometry and dual-energy X-ray absorptiometry) and degree of maturity will be discussed in this review. Components of body composition show age-to-age correlations (i.e. 'tracking'), especially from adolescence onwards. Furthermore, adipose tissue is endocrinologically active and is centrally involved in the interaction between adipocytokines, insulin and sex-steroid hormones, and thus influences cardiovascular and metabolic disease processes. In conclusion, pubertal body composition is important, not only for the assessment of contemporaneous nutritional status, but also for being linked directly to the possible onset of chronic disease later in life and is, therefore, useful for disease risk assessment and intervention early in life.

Age at menarche and racial comparisons in US girls.

BACKGROUND: Concern regarding change in the onset of sexual maturation of US girls has increased the need for current information on age at menarche from a national sample. Previous reports have been sparse and interpretation has been limited because of the racial composition and ages of the samples. OBJECTIVE: The objectives of this study were to estimate the distribution of age at menarche for all US girls and for non-Hispanic white, black, and Mexican American girls in the Third National Health and Nutrition Examination Survey and to test for racial differences. DESIGN: Menstrual status data were collected from 2510 girls aged 8.0 to 20.0 years. The Third National Health and Nutrition Examination Survey followed a complex, stratified, multistage probability cluster design. SUDAAN was used to calculate proportions of girls reaching menarche at an age. Ages at menarche were estimated by probit analysis at the ages at which 10%, 25%, 50%, 75%, and 90% of the girls attained menarche. RESULTS: Less than 10% of US girls start to menstruate before 11 years, and 90% of all US girls are menstruating by 13.75 years of age, with a median age of 12.43 years. This age at menarche is not significantly different (0.34 years earlier) than that reported for US girls in 1973. Age at menarche for non-Hispanic black girls was significantly earlier than that of white girls at 10%, 25%, and 50% of those who had attained menarche, whereas Mexican American girls were only significantly earlier than the white girls at 25%. CONCLUSION: Overall, US girls are not gaining reproductive potential earlier than in the past. The age at menarche of non-Hispanic black girls is significantly earlier than that of non-Hispanic white and Mexican American girls.