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Biomedical subjects

W C Chumlea

Publications and source records attributed to W C Chumlea.

107 records · Page 6Linked to original sources
PubMed1981

Size and number of adipocytes and measures of body fat in boys and girls 10 to 18 years of age.

In 111 boys and girls, 10 to 18 yr of age, body density was measured by underwater weighing, and the size of adipocytes in adipose tissue from the buttocks was measured by the osmium tetroxide method. From these two measures, estimates of percentage body fat, total body fat, and adipocyte number were computed for most of the children. Their skeletal age was also calculated by an acceptable method. Across chronological age, the girls have significantly larger mean values of total and percentage body fat and larger and more numerous adipocytes than the boys. The mean number of adipocytes in each sex is within adult levels, as is the mean size of the adipocytes in the girls. The boys' mean adipocyte size is below the adult level. There are negative, significant correlations between percentage body fat and chronological or skeletal age in the boys, and positive significant correlations between total body fat and chronological or skeletal age in the girls. Also, adipocyte size is positively correlated with percentage body fat but only in the boys. With the effects of chronological age removed, percentage body fat was significantly and negatively correlated with skeletal age in boys only. All other correlations among the variables were not statistically significant.

Adipose Tissue↗
PubMed1981

Adipocytes and adiposity in adults.

Measures of adipocyte size and body density were collected from 217 nonobese adults 20 to 50 yr of age, and estimates of total body fat, percentage body fat, and adipocyte number were calculated. Women had a greater percentage body fat than men in every age group except the oldest. Women had significantly greater amounts of total body fat and larger adipocytes than men in the 20- to 24-yr group, but men had significantly greater amounts of total body fat than the women in the 45- to 50-yr group. Adipocyte number, total body fat, and percentage body fat are each positively correlated with age in both sexes. Adipocyte size is not correlated with age but is positively correlated with total and percent body fat in men and women irrespective of age. These cross-sectional data suggest that adipocyte number, rather than being stable during adulthood, increases with age and is associated with corresponding increases in total and percentage body fat.

Adipose Tissue↗
PubMed1981

Brachymesophalangia of the fifth finger, stature, and weight in children with Down syndrome.

In summary, children with Down syndrome, eight to fifteen years of age, who have BMP-5, do not differ in stature or weight from children the same age with Down syndrome who do not have BMP-5. Many individuals with Down syndrome, who have BMP-5 as children, do not have the condition in adulthood. Also, in some children with Down syndrome, BMP-5 appears at one age, but not the next and vice versa.

Adolescent↗
PubMed1980

Communalities for rates of diaphyseal elongation of short bones of the hand of children with Down syndrome.

Communality indices for rates of elongation of diaphyses of short bones of the hand were computed from serial data for children with Down syndrome, 7 to 14 years of age. Communalities were larger for adjacent than for nonadjacent bones and also larger for bones grouped in rows rather than rays of the hand. This pattern is similar to that reported for normal children. Communality indices for rates of diaphyseal elongation for girls with Down syndrome were lower than those of boys with Down syndrome and normal children.

Anthropometry↗
PubMed1979

Growth of short bones of the hand in children with Down's syndrome.

In this study, we report the elongation of the diaphyses of the short bones of the hand in an institutionalised sample of children with Down's syndrome. These diaphyses are significantly shorter than normal which is typical of other physical dimensions of individuals with Down's syndrome. Sex differences were generally lacking in diaphyseal lengths; this is in agreement with earlier reports. Pubescent spurts were not detected, but their absence cannot be certain. Roche (1965) reports the common absence of pubescent spurts in stature in children with Down's syndrome. However, only the magnitude of growth in stature of a small sample of these Down's children differed from normal; this dissimilarity was the result of differences in adult statures of normal and Down's individuals (Rarick, Wainer, Thissen and Seefeldt, 1975). Benda (1960) speculates that growth of the short bones of the hand stops early; thus, the pubescent spurt may be prevented by premature, epiphyseal closure. This would be in partial agreement with reports for stature (Roche, 1965). In this sample of children with Down's syndrome the extra chromosome, No. 21, appears to affect the growth of short bones of the hand before seven years of age. The diaphyses of short bones of the hand in these children are shorter than normal by seven years of age and significantly so after eleven years of age; but thereafter, these bones grow normally except for the absence of a pubescent spurt. This pattern is similar to reports of growth in length of other parts of the skeleton in children with Down's syndrome.

Adolescent↗
PubMedDate not supplied

Assessing the body composition of 6-17-year-old Black and White girls in field studies.

The purpose of the study was to develop ethnic-specific equations for fat-free mass (FFM) from selected anthropometric dimensions and bioelectrical impedance measures of resistance (R) and reactance (Xc) for use in the NHLBI Growth and Heath Study. Using dual-energy X-ray absorptiometry measures of body composition as the dependent variable and field measures of body composition by anthropometry and bioelectrical impedance as the explanatory variables, ethnic-specific prediction equations were developed on a sample of girls representing a wide range of ages and BMI. The equations were cross-validated using (1) the Prediction of Sum of Squares (PRESS) statistic and (2) an independent sample of 20 girls of each race from a study conducted at the National Institute of Child Health and Human Development (NICHD). Subjects were 65 White and 61 Black girls 6-17 years of age. The best race-specific equations for FFM each explained 99% and 97% of the variance in the White and Black girls, respectively. Root mean square errors (RMSE) ranged from 1.14 to 1.95 kg. The equation for Black girls used Stature2/Resistance (R), weight, and reactance (Xc) as predictor variables; the equation for White girls used Stature2/R, weight, and triceps skinfold thickness. The results indicate that (1) equations to predict FFM in girls should be ethnic-specific and that (2) accurate values for TBF and %BF can be calculated from the predicted FFM.

Adolescent↗
PubMedDate not supplied

Bioelectrical impedance methods in clinical research: a follow-up to the NIH Technology Assessment Conference.

In 1994, the National Institutes of Health (NIH) convened a Technology Assessment Conference "to provide physicians with a responsible assessment of bioelectrical impedance analysis (BIA) technology for body composition measurement." In 1997, Serono Symposia USA, Inc., organized an invited panel of scientists and clinicians, with extensive research and clinical experience with BIA, to provide an update. Panel members presented reviews based on their own work and published studies for the intervening years. Updates were provided on the single and multifrequency BIA methods and models; continued clinical research experiences; efforts toward establishing population reference norms; and the feasibility of establishing guidelines for potential diagnostic use of BIA in a clinical setting. This report provides a summary of the panel's findings including a consensus on several technical and clinical issues related to the research use of BIA, and those areas that are still in need of additional study.

Body Composition↗
PubMedDate not supplied

Age- and maturity-related changes in body composition during adolescence into adulthood: the Fels longitudinal study.

We examined patterns of change in body composition from 8 to 20 yrs of age and the effects of rate of maturation on these patterns using serial data for total body fat (TBF). There is a continual increase, but a declining rate of change with age in TBF. For %BF the same pattern as for TBF exists for females, but for males the pattern of change in percentage body fat (%BF) reflects the concurrent changes in fat free mass (FFM). For FFM, there is an increase in females that slows at older ages, but in males there is a continual rapid increase until young adulthood. There is marked tracking for body composition persisting from childhood to adulthood. At the same age, rapidly maturing children have significantly larger TBF, %BF and FFM than slowly maturing children.

Adipose Tissue↗
PubMedDate not supplied

Adult changes in body composition are associated with changes in cholesterol levels: the Fels longitudinal study.

Serial data from 507 adult participants in the Fels Longitudinal Study were used to study relationships between average annual changes in serum cholesterol levels and annual changes in total body fat, fat-free mass, percent body fat or body mass index in men and women aged 18-45 years or 45-65 years. Average annual changes in adiposity before and after 45 years of age for men and women show statistically significant, strong, positive relationships with corresponding changes in cholesterol levels.

Adipose Tissue↗
PubMedDate not supplied

Weight at menarche in deaf girls.

Weight at menarche of a mixed longitudinal sample of deaf American girls was analysed with regard to its variability and association with their earlier than normal age at menarche. The 'critical weight' hypothesis of Frisch and Revelle (1970, 1971) specifies the attainment of a certain body weight necessary for the onset of menstruation with a concomitant reduction in its variability. The findings herein suggest this hypothesis is not applicable to deaf girls.

Aging↗
PubMedDate not supplied

Blood pressure, body composition, and fat tissue cellularity in adults.

While total body mass has been recognized for many years as having a strong positive association with blood pressure, it is not known whether body mass per se is important in this association or if a component of total mass, such as lean body mass or total body fat, is responsible for the relationship. To determine the relative importance of these components, 217 healthy adults unselected with respect to blood pressure or body composition, who were 18 to 49 years of age (X +/- sd = 33.1 +/- 8.9 years) had body density measured by underwater weighing. Body density was used to estimate percent body fat from which lean body mass and total body fat mass were determined. In addition, an adipose tissue biopsy from the gluteal area was made, and average fat cell size was measured using the osmium tetroxide method; fat cell number was then estimated. In both males and females, after adjusting for age, there were highly significant, positive partial correlations (r = 0.2 to 0.3) between measures of blood pressure (systolic, diastolic, and mean arterial) and percent body fat, total body fat mass or fat cell number. No significant correlation existed between lean body mass or fat cell size and any measure of blood pressure. These findings suggest that fat mass as opposed to body mass, per se, may be an important etiological component in elevated blood pressure in adults.

Adipose Tissue↗
PubMedDate not supplied

Development of the Chinese nutrition screen (CNS) for use in institutional settings.

OBJECTIVES: To develop and validate a nutritional screening tool (CNS) for elderly Chinese subjects in the institutional setting. DESIGN: Using the MNA as a guide, a questionnaire was developed appropriate for the Chinese health care system, diet, food customs and culture, using physician assessment for comparison. PARTICIPANTS: 200 men and 200 women aged 65 years or older, approximately equally distributed by age between two cities in China (Hong Kong and Shanghai), were recruited from hospitals and old age homes for the reliability study. 340 men and 527 women were recruited for the validity study. RESULTS: The CNS compared with physician assessments based on two groups, normal or at risk with less than normal nutritional status, had kappa coefficients of 0.5 overall and were as high as 0.8 in Shanghai. CNS was able to identify about 90% of all persons with normal nutritional status and had about a 60% chance of correctly identifying a person at risk with a less than normal nutritional status. CONCLUSION: The CNS can be used in a 2-group classification to identify those who have a normal nutritional status (CNS > or = 21). Those who do not fall into this group should have their nutritional status evaluated in greater detail (CNS score < or = 20). The applicability of screening tools may vary depending on the site and the population characteristics.

Aged↗
PubMedDate not supplied

Is the MNA valid in different populations and across practice settings?

OBJECTIVE: The MNA is a successful screening tool in geriatric medicine, but this success is in Europe or countries with Western health care practice settings. The MNA is not directly applicable in many ethnic groups or countries or those with non-Western cultural and dietary habits or health care systems. There is an increased prevalence of type 2 diabetes, the metabolic syndrome and obesity among the elderly; however, the MNA does not include questions or measures related to these or other important health conditions affected by nutritional status. This paper addresses the relevance of anthropometry and the impact of different clinical practice settings on the MNA and discusses the development of the Chinese Nutritional Screen (CNS) in China. CONCLUSIONS: If the MNA is to continue to be successful among groups of elderly around the world, then the MNA, CNS or similar instruments should be as country or culturally and ethnically specific as possible. The development of the CNS maintained the underlying assumptions and concept of the MNA but modified them for a country with diverse food and cultural habits and health care settings.

Aged↗
PubMedDate not supplied

Anthropometry and body composition in the perspective of nutritional status in the elderly.

Understanding normal changes in the body's composition with old age and their health and nutritional implications is important in determining the nutritional status of the elderly. Suitable reference data for anthropometry and body composition obtained from large representative samples of black, white, Hispanic, and Asian elderly persons are needed to improve their nutritional health and care. Distribution statistics for body measurements of persons 65 to 80 years of age are available from national health and nutrition surveys, but for persons older than 80 years, there is little information. Recumbent anthropometric techniques have been developed that are applicable. Underwater weighing continues to be a gold standard for determining body composition in the elderly, but a four-compartment model would improve estimates of body composition in the elderly because of changes in the density of the fat-free mass with old age. Noninvasive methods such as anthropometry and bioelectric impedance could be used to predict body composition if they were validated against direct methods and if appropriate equations become available.

Aged↗