W. Cameron Chumlea

Health status of children with moderate to severe cerebral palsy

The aim of the study was to evaluate the health of children with cerebral palsy (CP) using a global assessment of quality of life, condition-specific measures, and assessments of health care use. A multicenter population-based cross-sectional survey of 235 children, aged 2 to 18 years, with moderate to severe impairment, was carried out using Gross Motor Function Classification System (GMFCS) levels III (n = 56), IV (n = 55), and V (n = 122). This study group scored significantly below the mean on the Child Health Questionnaire (CHQ) for Pain, General Health, Physical Functioning, and Impact on Parents. These children used more medications than children without CP from a national sample. Fifty-nine children used feeding tubes. Children in GMFCS level V who used a feeding tube had the lowest estimate of mental age, required the most health care resources, used the most medications, had the most respiratory problems, and had the lowest Global Health scores. Children with the most severe motor disability who have feeding tubes are an especially frail group who require numerous health-related resources and treatments. Also, there is a relationship among measures of health status such as the CHQ, functional abilities, use of resources, and mental age, but each appears to measure different aspects of health and well-being and should be used in combination to reflect childrens overall health status.

Growth and Health in Children With Moderate-to-Severe Cerebral Palsy

BACKGROUND. Children with cerebral palsy frequently grow poorly. The purpose of this study was to describe observed growth patterns and their relationship to health and social participation in a representative sample of children with moderate-severe cerebral palsy. METHODS. In a 6-site, multicentered, region-based cross-sectional study, multiple sources were used to identify children with moderate or severe cerebral palsy. There were 273 children enrolled, 58% male, 71% white, with Gross Motor Function Classification System levels III (22%), IV (25%), or V (53%). Anthropometric measures included: weight, knee height, upper arm length, midupper arm muscle area, triceps skinfold, and subscapular skinfold. Intraobserver and interobserver reliability was established. Health care use (days in bed, days in hospital, and visits to doctor or emergency department) and social participation (days missed of school or of usual activities for child and family) over the preceding 4 weeks were measured by questionnaire. Growth curves were developed and z scores calculated for each of the 6 measures. Cluster analysis methodology was then used to create 3 distinct groups of subjects based on average z scores across the 6 measures chosen to provide an overview of growth. RESULTS. Gender-specific growth curves with 10th, 25th, 50th, 75th, and 90th percentiles for each of the 6 measurements were created. Cluster analyses identified 3 clusters of subjects based on their average z scores for these measures. The subjects with the best growth had fewest days of health care use and fewest days of social participation missed, and the subjects with the worst growth had the most days of health care use and most days of participation missed. CONCLUSIONS. Growth patterns in children with cerebral palsy were associated with their overall health and social participation. The role of these cerebral palsy-specific growth curves in clinical decision-making will require further study.

Prediction of stature from knee height for black and white adults and children with application to mobility-impaired or handicapped persons

OBJECTIVE No adequate methods exist for predicting stature to help assess the growth of handicapped (including mobility-impaired) children or to help in developing indexes of obesity or equations for estimating basal energy expenditure for adults. In this project, equations were developed to predict stature in white and black adults and children from nationally representative samples for application to mobility-impaired and handicapped persons. SAMPLES Samples of healthy adults (n = 5,415) and children (n = 13,821) were selected from cycles I, II, and III of the National Health Examination Survey (NHES) conducted by the National Center for Health Statistics from 1960 to 1970. Balanced validation and cross-validation groups were created with regard to age, ethnic group, and sex. OUTCOME MEASURES The NHES is the only national survey that contains body measurements biologically appropriate for predicting stature. These measurements include stature, sitting height, knee height, and buttocks to knee length. STATISTICAL ANALYSIS Equations were computed from an all-possible-subsets of weighted regression procedure to select the predictor variables in the validation group based on the values of R2 and the root mean square error. RESULTS Knee height predicted stature for white and black men, but the predictor variables for white and black women were knee height and age. For predicting stature in children 6 to 18 years of age, the predictor variable was knee height for all children. APPLICATIONS The equations presented here were developed for use with mobility-impaired or handicapped persons, but the measurements were collected from ambulatory people by means of standard techniques. The use of recumbent anthropometric data from mobility-impaired or handicapped persons in the equations will expand the errors of prediction over those presented in this report. The standard error for a person is a guide to the range of probability within which a predicted value can occur.

Anatomical Patterning of Visceral Adipose Tissue: Race, Sex, and Age Variation

Objective: We tested sex, race, and age differences in the patterning of visceral adipose tissue (VAT) and subcutaneous adipose tissue.

Sex Differences in Bone Mass Acquisition During Growth: The Fels Longitudinal Study

Risk of osteoporosis in later life may be determined during adolescence and young adulthood. The present study used longitudinal data to examine the accumulation of bone mineral content (BMC) and bone mineral density (BMD) in Caucasian subjects ages 6-36 yr. Growth in BMC and BMD (measured by dual X-ray absorptiometry; Lunar, Madison, WI) of 94 males and 92 females was monitored for a mean period of 4.29 yr. The main findings were that there were no sex differences in BMC or BMD during the prepubertal stage; however, females had significantly higher BMD of the pelvis and BMC and BMD of the spine during puberty, and postpubertal males generally had significantly higher BMC and BMD than their female counterparts. In addition, the longitudinal rate of bone accumulation in both sexes increased rapidly during childhood and adolescence and was nearly complete at the end of puberty. Finally, peak BMC and BMD was achieved between the ages of 20 and 25 and occurred earlier in females than in males. The rates of growth and timing of peak bone mass as reported here define the crucial period during which intervention protocols should be developed for maximizing skeletal mass to prevent the development of osteoporosis.

Family History and Risk of Hair Loss

Introduction: The genetic basis of androgenetic alopecia (AGA) is well accepted in the medical community and among the general population. However, rigorous studies investigating the familial basis of AGA are lacking. The purpose of the current study was to explore the relationship between family history and expression of AGA in a sample of men from the general community. Methods: Hair loss was assessed by an independent observer trained by an expert dermatologist using the Norwood/Hamilton classification scale and a 7-point global description of hair loss. Men were classified into two groups, one as having little or no hair loss and the other having hair loss. The family history of hair loss in parents and grandparents was assessed by subject self-report. Results: Adjusting for age, men whose fathers had hair loss were 2.5 times as likely to have had some level of hair loss compared to men whose fathers had no hair loss (95% CI: 1.3–4.9). Likewise, men whose fathers had hair loss were twice as likely to have hair loss than men whose fathers had no hair loss even after adjusting for age (OR = 2.1, 95% CI: 1.2–3.7 and OR = 2.5, 95% CI: 1.4–4.7 for Norwood/Hamilton and global description of hair loss assessments, respectively). Conclusion: Results suggest that the probability of male pattern hair loss is dependent on family history and age. Hair loss in a man’s father also appears to play an important role in increasing a man’s risk of hair loss, either in conjunction with a history of hair loss in the mother or hair loss in the maternal grandfather.

Body composition measures from underwater weighing and dual energy X-ray absorptiometry in black and white girls: a comparative study

The purpose of this study was to compare estimates of body composition in two ethnic groups, 31 black and 38 white girls 10 through 16 years of age, to establish accurate and precise laboratory standards for field measures of body composition in the NHLBI Growth and Health Study HC 55025. The dual energy X‐ray absorptiometry (DXA) measures of fat free mass (FFM) and % body fat (%BF) were made using Hologic QDR‐1000/W. Corresponding values of FFM and %BF from underwater weighing (UWW) were determined using the two‐component model of Siri, and these were corrected using the model of Lohman for white girls only. In the comparison of the different models and methods, the two‐component model overestimated FFM compared to estimates from DXA for black girls, as did the corrected Lohman model for white girls. The two‐component model significantly overestimated %BF in both white and black girls compared to corresponding estimates from DXA. The ratio of bone mineral content (BMC)/FFM affected the degree of %BF differences in black girls but not in white girls. Also, as the density of FFM increased or approached adult status in black girls (BMC/FFM increased), differences between the two‐component model and estimates from DXA decreased. In both groups of girls, the relationship of %BF from UWW and DXA are a function of the level of body fatness. DXA values of %BF are greater than those from UWW under about 24% body fat, but the converse occurs above 25% body fat. The inability of UWW using the two‐component model to account for the body composition in these girls can be corrected in part by measuring the variables for a multicomponent model or more easily by using DXA estimates of body composition.

Rapid Infant Weight Gain and Advanced Skeletal Maturation in Childhood

OBJECTIVE To test the hypothesis that rapid infant weight gain is associated with advanced skeletal maturity in children from the United States and South Africa. STUDY DESIGN Longitudinal data from 467 appropriate-for-gestational-age infants in the Fels Longitudinal Growth Study (Dayton, Ohio) and 196 appropriate-for-gestational-age infants in the Birth to Twenty birth cohort study (Johannesburg, South Africa) were used. Multiple linear regression models tested the association between internal SD score change in weight from 0 to 2 years and relative skeletal age at 9 years, adjusting for body mass index, stature, and other covariates. RESULTS In both studies, faster infant weight gain was associated with more advanced skeletal maturity (approximately 0.2 years or 2.4 months per SD score) at age 9 years (P <.0001-.005), even when adjusting for the positive associations of both birth weight and body mass index at age 9 years. This effect appeared to be accounted for by the greater childhood stature of subjects with more rapid infant weight gain. CONCLUSIONS Relatively rapid infant weight-gain is associated with advanced skeletal development in late childhood, perhaps via effects on stature.

Epidemiological Perspective on Body Composition Methodology

The numerous methods of measuring body composition may be classified as direct and indirect. Direct methods are applied in clinical research studies that address specific components of body tissues or chemical or molecular elements. Most direct methods, however, are cumbersome because of equipment complexity, invasiveness, and cost, limiting their application in field and epidemiological studies. Indirect methods lack the accuracy of more direct laboratory methods, but ease of use in large populations makes them suitable for epidemiological studies.