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Biomedical subjects

W C Chumlea

Publications and source records attributed to W C Chumlea.

At least 37 records · Page 2Linked to original sources
PubMed1999

Total body water data for white adults 18 to 64 years of age: the Fels Longitudinal Study.

BACKGROUND: Total body water (TBW) volume is reported to decrease with age, but much of the published data are 20 to almost 50 years old and are cross-sectional. Proper interpretation of clinical levels of TBW and trends with age necessitates the availability of current longitudinal data from healthy individuals. METHODS: Mixed longitudinal data for TBW of 274 white men and 292 white women (18 to 64 years of age) in the Fels Longitudinal Study were collected on a regular schedule over a recent eight-year period. The concentration of deuterium was measured by deuterium nuclear magnetic resonance spectroscopy. Body composition estimates were made with dual-energy x-ray absorptiometry, and random effect models were used to determine the patterns of change over time with and without covariates. RESULTS: The mean TBW data for the Fels men are either similar to or approximately 2 to as much as 6 liters greater than that reported by most other investigators 20 to 50 years ago. For Fels women, the mean TBW ranges from approximately 2 to as much as 5 liters less than that reported previously. These comparisons with much earlier studies reflect cohort effects and the secular changes in overall body size that have occurred during the past 60 to 70 years. These findings are reinforced by the fact that some early data sets included individuals born almost 140 years ago. After adjusting for the covariate effects of total body fat (TBF) and fat-free mass (FFM) with age, there were no significant age or age-squared effects on TBW in the men. In the women, after adjusting for the covariate associations of TBF and FFM with age, there was a small, but significant, negative linear association of TBW with age. In the men and women, the mean ratio of TBW to weight declined with age as a function of an increase in body fatness and more so for the men than the women. CONCLUSION: The findings from these mixed longitudinal data indicate that TBW volume, on average, maintains a reasonable degree of stability in men and women through a large portion of adulthood. These TBW data are recommended as current reference data for healthy adults.

Adipose Tissue↗
PubMed1999

Tracking of body mass index in children in relation to overweight in adulthood.

Body mass index (BMI; in kg/m2) values at or above the 75th percentile are associated with increased morbidity and mortality in adulthood, and there are significant correlations between BMI values in childhood and in adulthood. The present study addresses the predictive value of childhood BMI for overweight at 35 +/- 5 y, defined as BMI >28 for men and BMI >26 for women. Analyses of data from 555 white children showed that overweight at age 35 y could be predicted from BMI at younger ages. The prediction is excellent at age 18 y, good at age 13 y, but only moderate at ages <13 y. For 18-y-olds with BMIs above the 60th percentile, the probability of overweight at age 35 y is 34% for men and 37% for women. A clinically applicable method is provided to assign an overweight child to a group with a known probability of high BMI values in adulthood.

Journal Article↗
PubMed1999

Aging, body composition, and lifestyle: the Fels Longitudinal Study.

BACKGROUND: Changes in body composition in men and women occur with age, but these changes are affected by numerous covariate factors. OBJECTIVE: The study examined patterns of change in body composition and determined the effects of long-term patterns of change in physical activity in older men and women and in menopausal status and estrogen use in women. DESIGN: Serial measures of height, weight, body mass index (BMI), total body fat (BF), percentage BF, and fat-free mass (FFM) from underwater weighing of 102 men and 108 women enrolled in the Fels Longitudinal Study were analyzed. Physical activity levels and menopausal status were included as covariates. RESULTS: There were significant age-related decreases in FFM and height and increases in total BF, percentage BF, weight, and BMI. Physical activity was associated with decreases in total BF, percentage BF, weight, and BMI in men and were associated with increases in FFM and decreases in total BF and percentage BF in women. Postmenopausal women had significantly higher total BF and percentage BF than did pre- and perimenopausal women. The longer the time since menopause the greater were the increases in weight, BMI, total BF, and percentage BF; however, estrogen use attenuated these increases. CONCLUSIONS: Low FFM can be improved by increased physical activity. The effects of an intervention program on body composition can be masked if only body weight or BMI is measured. The effects of physical activity were more profound in postmenopausal than in premenopausal women, and estrogen use had beneficial effects on body composition.

Adult↗
PubMed1999

Body mass and bone mineral quality.

During adulthood, the amount and quality of muscle and bone mineral decreases, whereas fat increases. Persons with low muscle mass and bone quality may not have the physical or structural strength to support the body. The dual-energy x-ray absorptiometer is used to measure the amount of muscle, fat, and the quality of bone mineral. Men have larger average amounts of muscle and bone, and greater average bone density than women. In women, the normal decrease of body mass and bone quality is accentuated by menopause. On average, blacks have a larger amount of muscle and more dense bones than whites. A person with a high peak bone mass can lose bone normally with age and still maintain good bone quality. Lifestyle, diet, and exercise are important to maintaining a healthy body and good bone quality. Physically active persons have increased levels of muscle and bone density. Age, sex, race, and lifestyle affect the level of, and changes in, body mass and bone mineral density.

Aged↗
PubMed1999

Nutritional support and aging in preoperative nutrition.

In the past 20 years, an increased interest geriatric nutrition has induced researchers to document the distribution and magnitude of nutritional problems in the elderly population. It has been observed that the prevalence of malnutrition is greatly affected by the general health status and autonomy of the elderly. Among free-living healthy elderly persons, the prevalence of protein-caloric undernutrition is low. As health and functional capacities deteriorate with age, however, the prevalence increases dramatically to 30-65% of those in home care, nursing homes or in hospital. Formal nutritional assessment has typically been absent from most published programmes of geriatric evaluation and comprehensive geriatric assessment. This is frequently because of the lack of a specific validated tool to assess nutritional status in older persons and, at least partly, to explain this phenomenon. The Mini Nutritional Assessment was developed and validated on large representative samples of elderly persons to address these specific issues. Recent experimental studies have shown that advanced malnutrition is much more difficult to treat in the elderly than in younger adults. Trials of nutritional support using oral supplements or enteral tube feeding have shown improved outcome in those identified as malnourished on admission to hospital.

Administration, Oral↗
PubMed1999

Change of body composition over an eight year period among Japanese university students.

This study examined the change of body composition in Japanese university students. Subjects were university students divided into two groups by sex for two different time periods: 67 males and 46 females for 1986-1987 and 47 males and 64 females for 1994-1995. Body height, weight, and underwater weight were measured to estimate the percentage of body fat. The fat mass index (FMI) was applied after adjusting fat mass and the fat-free mass index (FFMI) applied after adjusting fat-free mass for body physique by dividing (body height)2. The mean body mass index (BMI) increased from 1986-1987 to 1994-1995 in males and decreased in females, although there were no statistical differences between two time periods in both sexes. The FMI indicates that in 1994-1995 males had significantly more fat adjusted for body height than in 1987. Females in 1994-1995 had significantly less FFMI than those in 1986 despite FMI similar to that of 1986. Our results thus warn against a trend toward excessive thinness in collegiate females and insufficiency of evaluating body composition using the BMI alone.

Adipose Tissue↗
PubMed1998

Stature prediction equations for elderly non-Hispanic white, non-Hispanic black, and Mexican-American persons developed from NHANES III data.

OBJECTIVE: To develop new, nationally representative equations to predict stature for racial/ethnic groups of the elderly population in the United States. DESIGN: Anthropometric data for stature, knee height, and sitting height for adults aged 60 years or older were collected from a sample of persons in the third National Health and Nutrition Examination Survey (1988-1994), a national probability sample of the US population. SUBJECTS: A gender- and racial/ethnic-stratified sample of 4,750 persons from the US population (1,369 non-Hispanic white men, 1,472 non-Hispanic white women, 474 non-Hispanic black men, 481 non-Hispanic black women, 497 Mexican-American men, 457 Mexican-American women) aged 60 years or older participated in this study. STATISTICAL ANALYSES: Sampling weights were used to adjust the individual data to account for unequal probabilities of selection, nonresponse, and coverage errors so that all individual data used in these analyses represented national probability estimates. Regression analysis was performed to predict stature in each gender and ethnic group, and the results were cross-validated. RESULTS: Stature prediction models using knee height and age and sitting height and age were evaluated for each gender and racial/ethnic group. The equations with knee height and age were selected on the basis of root mean square error and pure errors in cross-validation and on the accuracy and validity of measures of knee height over sitting height. Results of these regressions, including regression coefficients, standard errors of the coefficients, multiple correlation coefficients, root mean square error, and the standard error for the individual for the final equations, are presented. CONCLUSIONS: New stature prediction equations using knee height and age are presented for non-Hispanic white, non-Hispanic black and Mexican-American elderly persons from current nationally representative data. These equations should be applied when a measure of stature cannot be obtained, for example, for persons with amputations of the leg, or with spinal curvature or who are confined to bed. Predicted stature values are acceptable surrogates in nutritional indexes.

Age Factors↗
PubMed1998

The hemodialysis pilot study: nutrition program and participant characteristics at baseline. The HEMO Study Group.

OBJECTIVE: Describe the nutrition program (assessments and interventions) and the participants' baseline nutritional characteristics in the Hemodialysis Pilot Study. DESIGN: Cross sectional survey in which hemodialysis patients were examined during 10 weeks of baseline (BL), before randomization study interventions (dose and flux). SETTING: Four hemodialysis centers (eight dialysis units in total). PATIENTS: Twenty-nine male (mean age, 63 years; range, 34 to 75) and 20 female (mean age, 61 years; range, 29 to 73) hemodialysis patients. INTERVENTIONS: None during BL. MAIN OUTCOME MEASURES: Feasibility of implementing the proposed nutrition program before conducting the full-scale trial, and description of baseline characteristics related to nutrition. RESULTS: A nutrition program was developed to assess nutritional status during BL and follow-up periods and to intervene in patients with weight loss or decreasing serum albumin. Methods for collecting biochemical, dietary and anthropometric data were implemented at four clinical centers. At baseline, mean protein intake estimated by single pool normalized protein catabolic rate was 0.95 +/- 0.21 gm/kg adjusted body weight (ABW) (n = 42) and by diet record assisted recalls (n = 47) 0.94 +/- 0.36 gm/kg ABW/d, respectively. Mean energy intake was 22.8 +/- 8 kcal/kg ABW/day (n = 39). Mean serum albumin concentration using the bromcresol green method was 3.8 +/- 0.4 gm/dL (n = 40). Mean body mass index was within the normal limits of 19-27 kg/m2. Mean skinfold thicknesses in females, but not males, were shifted toward the lower end of usual distributions for healthy individuals. CONCLUSIONS: The goal of designing, developing, and implementing the diet and nutrition component, and related data collection for the HEMO pilot study was accomplished at four separate clinical centers. Baseline mean protein and energy intake were low, suggesting that continuing dietary surveillance is needed. The ongoing full-scale HEMO study will provide the first prospective analysis of dietary intake, nutritional status, and outcome in maintenance hemodialysis patients as a function of dialysis dose and membrane flux.

Adult↗
PubMed1998

Total-body and regional bone mineral content and areal bone mineral density in children aged 8-18 y: the Fels Longitudinal Study.

BACKGROUND: Techniques for cross-calibration of bone mineral content (BMC) and bone mineral density (BMD) between manufacturers of dual-energy X-ray absorptiometry (DXA) instruments are currently inadequate for total body measurements. Therefore, manufacturer-specific data for BMC and BMD in children are needed. OBJECTIVE: We provided age- and sex-specific means and SDs for total-body and regional BMC and areal BMD in 8-18-y-old white children. DESIGN: BMC and BMD of the head, arms, legs, pelvis, spine, and total body were determined by DXA. Data include 465 annual measurements from 148 healthy children with body weights between 30 and 100 kg and statures <190 cm. RESULTS: There were significant sex differences in BMC at ages 15-18 y for the total body and legs, at ages 12 and 15-18 y for arms and pelvis, at ages 11-13 and 16-18 y for the spine, and at ages 10-11 y for the head. There were significant sex differences in BMD at ages 16-18 y for total body, arms, and legs; at ages 12-13 and 16-18 y for the pelvis; at ages 12-14 and 18 y for the spine; and at ages 13-18 y for the head. CONCLUSIONS: Data presented in this investigation can be used to compare the BMC and BMD of 8-18-y-old white children (with statures <190 cm and body weights between 30 and 100 kg) using DXA.

Absorptiometry, Photon↗
PubMed1998

Prevalence of male pattern hair loss in 18-49 year old men.

BACKGROUND: Previous studies investigating the prevalence of male pattern hair loss (MPHL) typically used biased samples of men recruited from clinical populations which may limit generalizability of findings to broader populations. OBJECTIVE: To obtain an updated and improved estimate of the occurrence of MPHL in healthy men residing in the community. METHODS: Community-based sample of healthy men aged 18-49 years participated in a study investigating the effects of MPHL. Participants completed a brief questionnaire self reporting degree of hair loss, general health-related quality of life (HRQL) and hair-loss-specific measures. A trained observer also rated each participant using standardized classification for MPHL. RESULTS: The proportion of men with moderate to extensive hair loss (type III or greater) was 42%. The proportion of men with moderate to extensive hair loss increased with increasing age, ranging from 16% for men 18-29 years of age to 53% of men 40-49. Twelve percent of the men were classified as having predominantly frontal baldness (type A variants). CONCLUSIONS: MPHL, especially frontal baldness, may be more common than previously reported.

Adolescent↗
PubMed1998

Effects of self-perceived hair loss in a community sample of men.

BACKGROUND: Few studies have quantified the psychosocial effects of hair loss using standardized instruments in men not seeking treatment for hair loss. OBJECTIVE: Examine self-perception of hair loss and its effects on men from the community. METHODS: Men 18-50 years of age recruited without regard to hair loss, from households near Dayton, Ohio, completed a questionnaire assessing self-perception of hair loss, satisfaction with hair appearance, hair-loss-specific effects and general health status. RESULTS: Men with greater hair loss had more bother, concern about getting older, perceived noticeability to others and greater dissatisfaction with their hair appearance than men with less hair loss. These effects decreased with age for men with hair loss, but regardless of age, perceived noticeability of hair loss increased monotonically with degree of hair loss. CONCLUSIONS: Men with greater hair loss report more negative effects due to their hair loss across all age groups, but the effects were more pronounced in younger men.

Adolescent↗
PubMed1998

Serial changes in body composition throughout adulthood and their relationships to changes in lipid and lipoprotein levels. The Fels Longitudinal Study.

Few studies have examined the relationships between measures of body composition and lipid and lipoprotein levels in long-term serial data from individuals unselected for cardiovascular disease- or obesity-related variables, and none have considered such extensive serial data as used in the current study. The aim was to examine in such individuals the associations between annual changes in lipid and lipoprotein levels and concurrent changes in total body fat, fat-free mass, percent body fat, and body mass index. Serial data from 1304 examinations of 423 adult white participants in the Fels Longitudinal Study were analyzed sex-specifically in 2 age groups, 18 through 44 years and 45 to 65 years. A regressive analytic approach utilized the long-term (4 to 20 years) serial data of individuals. Annual changes in adiposity, independent of levels of lean tissue changes, before and after age 45 for men and women were significantly correlated with corresponding annual changes in cholesterol and low density lipoprotein cholesterol. In men before age 45, changes in triglycerides and high density lipoprotein cholesterol were also significantly associated with changes in adiposity, with the relationship remaining after age 45 in high density lipoprotein cholesterol. Increases in adiposity in individuals are associated with changes in lipid and lipoprotein levels in the direction of increased risk for cardiovascular disease. Adult levels of total cholesterol and low density lipoprotein cholesterol across age and sex and high density lipoprotein cholesterol in men are responsive to changes in adiposity, independent of initial adiposity or lipid and lipoprotein levels.

Adolescent↗
PubMed1997

Growth in weight, recumbent length, and head circumference for preterm low-birthweight infants during the first three years of life using gestation-adjusted ages.

Data from 867 preterm low-birthweight participants in the Infant Health and Development Program (IHDP) were used to develop reference data for growth status at an age and for increments from term to 36 month gestation-adjusted age (GAA). Weight, length and head circumference were recorded at 4 month intervals in the first year and at 6 month intervals in the second and third years. Selected percentiles for values at an age (status values) and increments for age intervals are presented in graphs separately for VLBW infants (< or = 1500 g at birth) and for LBW infants (1501-2500 g at birth). Percentiles of weight increments are presented beginning shortly before term for 1 month intervals to 6 month GAA, for 2 month intervals to 12 month GAA, and for 3-month intervals to 36 month GAA. Percentiles for length and head circumference increments are presented from term to 6 months for 2-month intervals, and to 36 month GAA for 3 month intervals. Among LBW infants, boys, had larger status and increment values than girls (P < 0.05), but there were no significant sex-associated differences in VLBW infants for status or increments. The mean status values and increments in weight and head circumference of the LBW infants were larger than those of VLBW infants, but the differences in length were not significant.

Aging↗
PubMed1997

Effect of dietary protein restriction on nutritional status in the Modification of Diet in Renal Disease Study.

The safety of dietary protein and phosphorous restriction was evaluated in the Modification of Diet in Renal Disease (MDRD) Study. In Study A, 585 patients with a glomerular filtration rate (GFR) of 25 to 55 ml/min/1.73 m2 were randomly assigned to a usual-protein diet (1.3 g/kg/day) or a low-protein diet (0.58 g/kg/day). In Study B, 255 patients with a GFR of 13 to 24 ml/min/1.73 m2 were randomly assigned to the low-protein diet or a very-low-protein diet (0.28 g/kg/day), supplemented with a ketoacid-amino acid mixture (0.28 g/kg/day). The low-protein and very-low-protein diets were also low in phosphorus. Mean duration of follow-up was 2.2 years in both studies. Protein and energy intakes were lower in the low-protein and very-low-protein diet groups than in the usual-protein group. Two patients in Study B reached a "stop point" for malnutrition. There was no difference between randomized groups in the rates of death, first hospitalizations, or other "stop points" in either study. Mean values for various indices of nutritional status remained within the normal range during follow-up in each diet group. However, there were small but significant changes from baseline in some nutritional indices, and differences between the randomized groups in some of these changes. In the low-protein and very-low-protein diet groups, serum albumin rose, while serum transferrin, body wt, percent body fat, arm muscle area and urine creatinine excretion declined. Combining patients in both diet groups in each study, a lower achieved protein intake (from food and supplement) was not correlated with a higher rate of death, hospitalization or stop points, or with a progressive decline in any of the indices of nutritional status after controlling for baseline nutritional status and follow-up energy intake. These analyses suggest that the low-protein and very-low-protein diets used in the MDRD Study are safe for periods of two to three years. Nonetheless, both protein and energy intake declined and there were small but significant declines in various indices of nutritional status. These declines are of concern because of the adverse effect of protein calorie malnutrition in patients with end-stage renal disease. Physicians who prescribe low-protein diets must carefully monitor patients' protein and energy intake and nutritional status.

Adolescent↗