Cadmium: in vivo measurement in smokers and nonsmokers.

Absolute amounts of cadmium (in milligrams) in the left kidney and concentrations of cadmium (micrograms per gram) in the liver were measured in vivo in 20 healthy adult male volunteers. Organ cadmium levels of smokers were significantly elevated above those of nonsmokers. No relationship was evident between body stores of cadmium (liver and kidney) and cadmium or beta 2-microglobulin in urine or blood. The average total body burden of cadmium in man at age 50 is estimated to be 19.3 milligrams for nonsmokers and 35.5 milligrams for smokers (38.7 pack-year smoking history). Biological half-time for the whole body was, on average, 15.7 years (10- to 33-year range). Dietary absorption was 2.7 micrograms per day. Cigarette smoking resulted in the absorption of 1.9 micrograms per pack.

Resource use in the last three months of life by lung cancer patients in southern Ontario.

Background: End-of-life cancer care involves multidisciplinary teams working in various settings. Evaluating the quality of care and the feedback from such processes is an important aspect of health care quality improvement. Our retrospective cohort study reviewed health care use by lung cancer patients at end of life, their reasons for visiting the emergency department (ed), and feedback from regional health care professionals. Methods: We assessed 162 Ontario patients with small-cell and relapsed or advanced non-small-cell lung cancer. Demographics, disease characteristics, and resource use were collected, and the consenting caregivers for patients with ed visits were interviewed. Study results were disseminated, and feedback about barriers to care was sought. Results: Median patient age was 69 years; 73% of the group had non-small-cell lung cancer; and 39% and 69% had received chemotherapy and radiation therapy respectively. Median overall survival was 5.6 months. In the last 3 months of life, 93% of the study patients had visited an oncologist, 67% had telephoned their oncology team, 86% had received homecare, and 73% had visited the ed. Death occurred for 55% of the patients in hospital; 23%, at home; and 22%, in hospice. Goals of care had been documented for 68% of the patients. Homecare for longer than 3 months was associated with fewer ed visits (80.3% vs. 62.1%, p = 0.022). Key themes from stakeholders included the need for more resources and for effective communication between care teams. Conclusions: Use of acute-care services and rates of death in an acute-care facility are both high for lung cancer patients approaching end of life. In our study, interprofessional and patient-provider communication, earlier connection to homecare services, and improved access to community care were highlighted as having the potential to lower the need for acute-care resources.

Evaluation of controlled-release devices for providing chromium sesquioxide and zinc in Huacaya alpacas at pasture.

OBJECTIVE: To assess the effectiveness of controlled-release devices (CRDs) for providing zinc and for estimating faecal output in alpacas and sheep at pasture. METHODS: The study groups of 10 alpacas and 10 sheep at pasture were paired within species and allocated at random to receive by mouth either one CRD containing chromium sesquioxide designed to function for at least 21 days or two CRDs, one containing chromium sesquioxide and the other zinc oxide designed to release over a nominal 60-day period. Faecal concentrations of chromium, zinc and ash, blood and plasma concentrations of zinc and plasma activity of alkaline phosphatase (ALP) were measured over a period of 117 days after treatment. RESULTS: The mean faecal chromium excretion profiles suggested that the CRDs performed in a similar manner in both species, releasing chromium for nearly 30 days in alpacas and for slightly more than 30 days in sheep. Using a common predetermined release rate of chromium from the CRDs, the daily faecal outputs of alpacas and sheep were estimated to be 0.54 kg dry matter and 0.33 kg dry matter, respectively. The CRD containing zinc oxide provided after 1 week an estimated daily release rate of 40 mg zinc with a lifetime of between 60 and 70 days in both species. The additional zinc did not elicit a response in blood zinc concentrations or in plasma ALP activity. CONCLUSION: The CRDs were retained in the gastrointestinal tracts of the alpacas and sheep and both types functioned as expected. The CRD delivering chromium sesquioxide at a known release rate provided an estimate of faecal dry matter output over a period of almost 3 weeks and the CRD formulated to deliver supplementary zinc did so at the nominal release rate over a period of approximately 60 days in both species. These data indicated that the standard sheep CRD is applicable for use in alpacas.

The metabolic effects of pregnancy in cystic fibrosis.

OBJECTIVE: Our purpose was to determine glucose tolerance in pregnant women with cystic fibrosis (CF) and to relate glucose tolerance to insulin sensitivity, hepatic glucose production, and protein turnover. METHODS: We studied 8 CF women during pregnancy (CFPreg). Results were compared with those from 9 pregnant controls (PregCont) and 8 nonpregnant CF women (CFCont). The following metabolic studies were conducted: oral glucose tolerance test (OGTT), hyperinsulinemic euglycemic clamp, stable isotope infusion of [1-13C]leucine and [6,6-2H2]glucose for measurement of whole body protein turnover and hepatic glucose production (HGP), respectively. Indirect calorimetry was used to measure resting energy expenditure (REE), and food intake was measured by 3-day food journals. Fat-free mass was measured by total body potassium 40K scan. RESULTS: All but one CFPreg developed diabetes by the end of the second trimester and had significantly lower insulin secretion and more insulin resistance than PregCont. Hepatic glucose production was significantly higher and suppression by insulin was less in CF subjects, and protein breakdown was significantly higher. Insulin resistance and HGP increased during pregnancy similarly in CFPreg and PregCont groups. CONCLUSION: Pregnancy in CF is associated with decreased insulin sensitivity and high HGP, in addition to inherent decreased insulin secretion. Pregnancy in CF is also associated with increased protein turnover and less response to insulin's anticatabolic effect. These changes appear to predispose the pregnant CF women to early development of diabetes and poor weight gain.

Bone assessment in children: comparison of fan-beam DXA analysis.

The newest version of whole body dual-energy X-ray absorptiometry (DXA) analysis software from Hologic (Discovery 12.1) is designed to enhance bone detection in smaller subjects. We re-analyzed 1127 pediatric scans (ages 1.8-18.5 yr) previously analyzed using software version 11.2. Regression analysis compared new and original results for bone area (BA), bone mineral content (BMC), bone mineral density (BMD), and DXA-derived body weight. Changes in total and regional bone results were compared with age, weight, and height. New results were highly correlated with original analyses (R2 > or = 0.9), but there were large differences at the individual subject level. The BA and BMC values increased in subjects less than 40 kg weight, resulting in a lower BMD. Original and new results were equivalent by about age 14 yr in both genders. Regional bone data showed the greatest changes in the legs. The newest software produces significant changes in bone values in subjects weighing less than 40 kg, compared with earlier versions. This effect increases with decreasing body weight. This will impact interpretation of longitudinal pediatric DXA studies, as well as existing pediatric whole body bone reference databases. Investigators must recognize which DXAsoftware version they are using, and which version produced any reference database they may use for comparison.

Bone mineral and body composition measurements: cross-calibration of pencil-beam and fan-beam dual-energy X-ray absorptiometers.

Pencil-beam dual-energy X-ray absorptiometers (DXA) are being replaced with instruments that rely solely on fan-beam technology. However, information has been lacking regarding the translation of bone mineral and body composition data between the two devices. We have compared total body scans using pencil-beam (Hologic QDR-2000W) and fan-beam (Hologic QDR-4500A) instruments for 33 children (ages 3-18 years) and 14 adults. Bone mineral content (BMC), bone mineral density (BMD), fat, lean, and body fatness (%fat) values were highly correlated (r2 = 0.984-0.998) between the two DXA instruments. The mean differences between the paired measurements were: deltaBMC = 7.5 +/- 73.6 g, deltaBMD = 0.0074 +/- 0.0252 g/cm2, delta lean = 1.05 +/- 1.8 kg, delta fat = -0.77 +/- 1.7 kg, and delta%fat = -0.94% +/- 2.5%. The BMC and BMD values were not statistically different, whereas the differences for the body composition values were significant (p < 0.02-0.005). Regression equations are provided for conversion of bone and body composition data between pencil-beam and fan-beam values for the whole body. To test the performance of these equations for a second group (23 subjects), predicted values were compared with the measured data obtained using the fan-beam instrument. The mean differences were -1.0% to 1.4%, except for body fat mass, where the difference was 6.4%. For cross-sectional studies, the two DXA technologies can be considered equivalent after using the translational equations provided. For longitudinal studies in which small changes in body composition for the individual are to be detected, we recommend that the same DXA instrument be used whenever possible. For example, transition from a pencil-beam to a fan-beam instrument could, in extreme cases, result in differences as large as 19% for the estimate of body fat mass.

Total body calcium and bone mineral content: comparison of dual-energy X-ray absorptiometry with neutron activation analysis.

The aim of this study was to compare the dual-energy X-ray absorptiometry (DXA) measurement of bone mass with an independent measure of body calcium obtained by neutron activation analysis (NAA). Total body bone mineral content (BMC) was measured using DXA in 46 subjects in the age range 5-47 years (17 children, 28 young women, and 1 adult male). Total body calcium (TBCa) was measured in the same subjects by in vivo NAA. The correlation between the two measures of bone mass was highly significant (BMC[g] = 3.22 x TBCa[g] - 51.4, r > 0.98, p < 0.0001, SEEBMC = 122.7 g). When BMC was the independent parameter, the SEETBCa was 37.5 g. Bland-Altman analysis indicated a mean difference of 2.8 g with a standard error +/- 4.7 g for TBCaNAA versus TBCaDXA when the BMC values were converted to TBCa. The relative change in bone mass (delta TBCa/delta BMC) for DXA was higher than that reported for dual-photon absorptiometry versus NAA. The findings presented in this study provide translational equations among the DXA and NAA measurements and for the conversion of total body BMC to TBCa in children and young adults.

Bone turnover response to changes in calcium intake is altered in girls and adult women in families with histories of osteoporosis.

Heredity and environmental factors contribute to the development of osteoporosis. Because calcium is the major mineral in bone and adolescence is a key period in bone acquisition, we hypothesized that bone turnover would be less responsive to alterations in dietary calcium intake in both girls and adult women from families with histories of osteoporosis. To address this issue, we studied calcium kinetics in the maternal grandmother (age range 56-81 years), mother (age range 32-47 years), and granddaughter (age range 8-15 years) in 10 multigenerational families. In five families, the mother and/or grandmother had osteoporosis (bone mineral density > or = 2 SD below the age-specific mean). To examine both active and passive calcium absorption, families consumed low- (279 +/- 64 mg/day) and high- (1580 +/- 385) calcium diets for 10 days prior to administration of oral (46Ca) and intravenous (42Ca) stable isotopes. Using repeated measures analysis of variance, fractional calcium absorption, true calcium absorption, bone calcium deposition, and the balance in bone calcium turnover were all significantly affected by diet (p < 0.01). Females from nonosteoporotic families had decreased bone calcium resorption with little change in bone calcium deposition during the high-calcium study. In contrast, girls and adult women from osteoporotic families had increased both bone calcium deposition and resorption during the high-calcium period, leading to a less positive balance in bone calcium turnover. A significant interaction between bone status and diet was found for bone calcium resorption (p < 0.05) and approached significance for bone calcium deposition (p < 0.07), effects which were independent of generation. We conclude that girls and women from osteoporotic families have a significantly altered bone turnover response to acute changes in calcium intake.

Vitamin D receptor gene Fok1 polymorphism predicts calcium absorption and bone mineral density in children.

The vitamin D receptor (VDR) gene has been implicated as one of the major genetic components of osteoporosis. We evaluated the relationship between markers of mineral status and restriction fragment length polymorphisms of the VDR gene in 72 healthy children age 7-12 years. Using stable isotope techniques and dual-energy X-ray absorptiometry, we measured dietary calcium absorption, bone calcium deposition rates, and total body bone mineral density (BMD). The Fok1 polymorphism at the VDR translation initiation site was significantly associated with BMD (p = 0.02) and calcium absorption (p = 0.04). Children who were FF homozygotes had a mean calcium absorption that was 41.5% greater than those who were ff homozygotes and 17% greater absorption than Ff heterozygotes. BMD was 8.2% greater in the FF genotype than the ff genotype and 4.8% higher than the Ff genotype. These results suggest a substantial relationship between the VDR gene and bone metabolism at one or more levels, including dietary absorption of calcium and BMD in growing children.

Z score prediction model for assessment of bone mineral content in pediatric diseases.

The objective of this study was to develop an anthropometry-based prediction model for the assessment of bone mineral content (BMC) in children. Dual-energy X-ray absorptiometry (DXA) was used to measure whole-body BMC in a heterogeneous cohort of 982 healthy children, aged 5-18 years, from three ethnic groups (407 European- American [EA], 285 black, and 290 Mexican-American [MA]). The best model was based on log transformations of BMC and height, adjusted for age, gender, and ethnicity. The mean +/- SD for the measured/predicted in ratio was 1.000 +/- 0.017 for the calibration population. The model was verified in a second independent group of 588 healthy children (measured/predicted In ratio = 1.000 +/- 0.018). For clinical use, the ratio values were converted to a standardized Z score scale. The whole-body BMC status of 106 children with various diseases (42 cystic fibrosis [CF], 29 juvenile dermatomyositis [JDM], 15 liver disease [LD], 6 Rett syndrome [RS], and 14 human immunodeficiency virus [HIV]) was evaluated. Thirty-nine patients had Z scores less than -1.5, which suggest low bone mineral mass. Furthermore, 22 of these patients had severe abnormalities as indicated by Z scores less than -2.5. These preliminary findings indicate that the prediction model should prove useful in determining potential bone mineral deficits in individual pediatric patients.

Issues and challenges in developing ruminal drug delivery systems.

Ruminants have a specialised digestive system that contains anaerobic bacteria and protozoa capable of digesting the cellulosic materials that are so common in plant materials. In addition, their distinct digestive system can change the metabolism and mode of action of some nutrients, medicines or other bioactive materials when delivered orally or may provide opportunities for alternative oral dosing strategies. In particular, there is interest in administering a relatively large depot of some drugs into the rumen, which then provides for a prolonged and sustained release of small quantities of these drugs over time. Any strategy to develop a new ruminal drug delivery system must take into account the characteristics of the digestive system of ruminants and its specific bioactive application. For example, in the case of products to control parasitic infections, the development of the host's immunity against the nematodes, which can be acquired during the pasture season, must be considered; likewise, where pharmacologically active materials are used to manipulate a particular metabolic or biochemical process, one must always be aware of interactions with other processes, which might eventuate. This article reviews the necessary concepts, the issues and the challenges to construct ruminal drug delivery systems.

Growth hormone decreases protein catabolism in children with cystic fibrosis.

Despite aggressive nutritional therapy, low body weight and protein catabolism are common problems in children with cystic fibrosis. Previous studies by our group and others have demonstrated improvement in both height and weight in children with cystic fibrosis who were treated with human recombinant GH, and our group has recently documented improved clinical status and lean tissue mass as well. The purpose of this report is to summarize our findings of the effect of GH on whole body protein kinetics in cystic fibrosis and to relate these findings to changes in TNF-alpha levels. We conducted a 1-yr study of 19 prepubertal children with cystic fibrosis (age 7-12 yr, all <94% of ideal body weight). Ten children were randomly assigned to take daily injections of GH (0.3 mg/kg.wk), and nine were randomly assigned to be controls. Baseline results from the subjects with cystic fibrosis were compared with results obtained from nine age- and gender-matched healthy children. Whole body protein turnover was measured at baseline and every 6 months using the stable isotope [1-(13)C]leucine and mass spectrometric analysis. Leucine rate of appearance, a measure of protein catabolism, was similar in both cystic fibrosis subgroups at baseline and was significantly higher than in the control children without cystic fibrosis. Treatment with GH resulted in a significantly lower leucine rate of appearance, as well as significantly lower leucine oxidation. The rate of protein synthesis, as calculated from these numbers, actually decreased in the cystic fibrosis subgroup. TNF-alpha levels were higher in both cystic fibrosis subgroups than in controls and correlated with leucine rate of appearance. The results of this study suggest that one reason GH improves body weight and lean tissue mass is due to improved whole body protein catabolism and improved efficiency of whole body protein kinetics.

Changes in body composition of human immunodeficiency virus-infected males receiving insulin-like growth factor I and growth hormone.

Weight loss is a common, persistent characteristic of long term human immunodeficiency virus (HIV-1) infection; its full etiology remains unknown. Because treatment with GH has induced nitrogen retention in various catabolic conditions, we designed this study to determine whether a moderate dose of insulin-like growth factor I (IGF-I) combined with a low GH dose could impede the catabolic response seen in HIV-1 infection. A double blind, placebo-controlled study design was used. Subjects in the GH/IGF-I treatment group (n = 44) and control group (n = 22) continued to receive their routine stable antiretroviral therapy. No patient had a recent history of opportunistic infection, malignancy, or Kaposi's sarcoma and had dietary intakes of at least 25 Cal/kg weight.day at study entry. During the 12-week study period, dietary instruction was given, and subjects were encouraged to maintain an intake of 35 Cal/kg and 1 g protein/kg. All subjects had a body mass index of 19.8 kg/m2 or less at the time of study entry or a weight loss of 10% or more of their premorbid weight and a body mass index below 26.1 kg/m2. The treatment group received 0.34 mg (0.68 mg/day) GH, twice daily, and 5.0 mg (10 mg/day) IGF-I, twice daily. Changes in body composition of total body potassium (TBK), total body nitrogen (TBN), fat-free mass (FFM), and body fat (Fat) were examined at 6 and 12 weeks during the treatment period. TBK, TBN, FFM, and Fat for the treatment and placebo groups were, on the average, below normal at study entry. At 6 weeks, the GH/IGF-I group showed a significant increase in FFM (P < 0.0001), a minimal increase in TBK (P < 0.05), and a substantial decrease in Fat (P < 0.01) compared with baseline values. The loss of body fat continued to be significant (P < 0.01) in the GH/IGF-I group treatment at 12 weeks, whereas the increase in FFM was minimal (P < 0.05). No significant changes in the mean body composition occurred at 6 or 12 weeks in the placebo group. By 12 weeks, neither TBK (body cell mass) nor TBN (total protein mass) had significantly increased relative to the values at baseline, although the FFM remained elevated. Thus, the combined GH and IGF-I doses used in this study in adult males with HIV-associated weight loss were ineffective in producing a sustained anabolic response and, in fact, resulted primarily in a significant loss of body fat.

Calcium absorption, bone mass accumulation, and kinetics increase during early pubertal development in girls.

To evaluate the changes in calcium and bone mineral metabolism associated with early pubertal development, we performed longitudinal measurements of calcium absorption, calcium kinetics, bone mineral content, and hormonal markers related to puberty in a multiethnic group of girls beginning when they were 7 or 8 yr old. Girls were Tanner stage 1 (breast) at the start of the study. They were placed on a 1200 mg/day dietary calcium intake and studied at approximately 6-month intervals until they reached Tanner stage 2 (breast). Results at that time point (PUB) were compared to values obtained approximately 1 yr earlier (LatePRE) and those 1 yr before that (EarlyPRE). We found an increase in calcium absorption comparing PUB to LatePRE (n = 34; 36.6 +/- 8.7% vs. 30.7 +/- 9.9%; P = 0.002). Using whole body, dual energy, x-ray absorptiometry scanning, we found an increase in calcium gain during the LatePRE to PUB period compared with that during the EarlyPRE to LatePRE period (135 +/- 53 vs. 110 +/- 45 mg/day; P = 0.04). Calcium kinetic studies showed a significant increase in the bone calcium deposition rate (Vo+) during the PUB compared to the LatePRE period. Hormonal and biochemical markers of bone development were also significantly increased at PUB compared to LatePRE. Hormonal activity, as evidenced by the unstimulated LH level, was significantly correlated with calcium gain between the LatePRE and PUB studies and the bone calcium deposition rate in the PUB study. These data demonstrate, using multiple independent methods, an increase in calcium utilization associated with the earliest physical signs of puberty.

Serum leptin concentrations in Caucasian and African-American girls.

Because African-American girls are heavier, taller, and mature earlier than Caucasian girls, we hypothesized that the serum leptin concentration differs between the two groups. Serum leptin concentrations were measured by immunoassay in 12-h fasted blood samples collected from 79 Caucasian and 57 African-American girls between 8 and 17 yr of age. Body composition was measured by dual-energy x-ray absorptiometry, sexual maturity by physical examination, and physical fitness by treadmill testing. Serum leptin concentrations were positively correlated (P < 0.01) with maturation, body fatness, and insulin and were higher (6.6 ng/mL, P < 0.01) in the African-American girls after adjusting for age. The difference remained significant (P < 0.01) but was reduced to 3.2 ng/mL after controlling for differences in maturation, fat mass, and physical fitness. The higher serum leptin levels might play an important role in the accelerated growth and sexual maturation of African-American girls.

Serum osteocalcin and total body calcium in normal pre- and postmenopausal women and postmenopausal osteoporotic patients.

Serum osteocalcin was measured in 51 normal pre- and 114 postmenopausal women and in 41 postmenopausal osteoporotic patients. Total body calcium (TBCa) was determined in the same individuals by neutron activation analysis. Many of the perimenopausal nonosteoporotic women had increased serum osteocalcin values, but 15 yr or more after the menopause most of the women had serum osteocalcin levels in the normal range. Comparing normal women before and after menopause, the mean serum osteocalcin levels [7.8 +/- 4.7 (+/- SE) and 10.1 +/- 9.4 ng/mL] were not significantly different; however, the TBCa values (898 +/- 99 and 806 +/- 111 g) were significantly different (P less than 0.001). When the normal postmenopausal women were regrouped according to high vs. low osteocalcin values, TBCa and phosphorus content as well as forearm linear bone density were significantly lower in the high osteocalcin group, even though most of the other variables, including urinary hydroxyproline excretion, serum alkaline phosphatase, age, height, and weight, were not different. Osteoporotic women had a mean serum osteocalcin concentration of 17.4 +/- 8.6 ng/ml and a TBCa of 657 +/- 83 g, both significantly different from the respective values in normal and pre- and postmenopausal women (P less than 0.001 for both variables in comparison to each group). These data suggest that high serum osteocalcin levels, at least on a group basis, are an index of low skeletal mass.

Pubertal African-American girls expend less energy at rest and during physical activity than Caucasian girls.

Between 1963 and 1991, the most dramatic increases in the prevalence of overweight in the United States have been reported in African-American girls. Lower basal energy expenditure and lack of physical activity are believed to be risk factors for excessive weight gain. We hypothesized that energy expenditure at rest and during physical activity are lower in pubertal African-American girls than in Caucasian girls. Basal metabolic rate and sleeping energy expenditure of 40 Caucasian and 41 African-American pubertal girls (matched for age, physical characteristics, body fat, and energy intake) were measured by whole-room calorimetry, energy expended for physical activity by the doubly labeled water method, sexual maturity by physical examination, body composition by dual-energy x-ray absorptiometry, physical fitness by treadmill testing, and energy intake by 3-day food record. After adjusting for soft lean tissue mass, the basal energy expenditure (1333 +/- 132 vs. 1412 +/- 132 kcal/day, P = 0.01) and energy expended for physical activity (809 +/- 637 vs. 1271 +/- 162 kcal/day, P < 0.01) were significantly lower in the African-American girls than in the Caucasian girls. The differences remained the same after controlling for differences in sexual maturity and/or physical fitness. The lower energy expenditure of the pubertal African-American girls suggests that they are at a higher risk of becoming overweight than their Caucasian counterparts.

A randomized, placebo-controlled trial of combined insulin-like growth factor I and low dose growth hormone therapy for wasting associated with human immunodeficiency virus infection.

Loss of body mass, or wasting, is a major cause of morbidity and a contributor to mortality in human immunodeficiency virus-1 (HIV-1) infection. Dietary supplements and appetite adjuvants have had limited effectiveness in treating this condition. GH and insulin-like growth factor I (IGF-I) have been shown to be anabolic in many catabolic conditions, and limited data suggest similar efficacy in HIV wasting. In addition, it appears that GH and IGF-I may have complementary anabolic effects with opposing glucoregulatory effects. We report results from a 12-week randomized, placebo-controlled trial of combination recombinant human GH (rhGH; Nutropin; 0.34 mg, sc, twice daily) and rhIGF-I (5.0 mg, sc, twice daily) in individuals with HIV wasting and without active opportunistic infection, cancer, or gastrointestinal disease. A total of 142 subjects (140 males and 2 females) were randomized using a 2:1, double blind treatment scheme and assigned to receive either active treatment or placebo injections. Eighty subjects completed the 12-week protocol. Nutritional intake and demographic and clinical characteristics did not differ between the groups at any study time point. At 3 weeks, the treatment group had a significantly larger weight increase (P = 0.0003), but this difference was not observed at any later time point. Similarly, fat-free mass, calculated from skinfold measurements, increased transiently in the treatment group at 6 weeks (P = 0.002). No significant differences in isokinetic muscle strength or endurance testing or in quality of life were observed between the groups. Resting heart rate was significantly higher in the treatment group at each time point post-baseline. GH and IGF-binding protein-3 levels did not change; however, IGF-I levels were higher in the treatment group at 6 and 12 weeks. There were no significant between-group differences in any of the measured biochemical or immunological parameters. rhGH plus rhIGF-I treatment was associated with an increased incidence of peripheral edema and other side-effects, possibly related to fluid retention. We conclude that the combination of rhIGF-I and low dose rhGH used in this study had no significant anabolic effect in HIV wasting.

Body composition of a young, multiethnic, male population.

The study objective was to establish the range of total body-composition values for a young, multiethnic, healthy male population (aged 3-18 y) by using dual-energy X-ray absorptiometry (DXA). Results for 297 males in three ethnic groups [European American (white), n = 145; African American (black), n = 78; and Mexican American (Hispanic), n = 74] are reported. Bone mineral content (BMC), lean tissue mass (LTM), body fat mass, and percentage fat are presented as functions of age. Analysis of variance with age, weight, and height as covariates was used to evaluate differences among the three ethnic groups. BMC and LTM were higher in black than in white males, but no difference in BMC or LTM was evident between the white and Hispanic groups. The relation between total-body BMC and LTM was linear (r = 0.985, P < 0.0001) and independent of age or ethnic classification. The Hispanic males had higher body fat values than the white group, whereas the black males generally had lower values than the white group. When adjusted for body size, the Hispanic males continued to have significantly higher body fat and percentage fat than the white or black males. Ethnic-specific equations for the prediction of body composition as a function of age, weight, and height were derived. The results for the white males in the present study were compared with DXA-derived reference data reported in other countries for young white males. We conclude that reference values of total body composition for young healthy males need to be ethnic specific.

Body composition of a young, multiethnic female population.

The study objective was to establish the range of body-composition values for a multiethnic female population (aged 3-18 y) by using dual-energy X-ray absorptiometry (DXA). Results for 313 females in three ethnic groups [European American (white), n = 141; African American (black), n = 104; and Mexican American (Hispanic), n = 68] are reported. Changes in the bone mineral content (BMC), lean tissue mass (LTM), fat mass, and percentage fat are presented as functions of age. Analysis of variance with age, weight, and height as covariates was used to evaluate differences among the three ethnic groups. BMC and LTM were higher in the black than the white females, but no significant difference in BMC or LTM was evident between the white and Hispanic groups. The relation between the BMC and LTM compartments was linear (r = 0.963, P < 0.0005) and independent of age or ethnic classification. The Hispanic and black females had higher percentage fat values than the white group. When adjusted for body size, the Hispanic females continued to have significantly higher fat mass and percentage fat than the white females in this study. Ethnic-specific equations for body composition as a function of age, weight, and height are given. In addition, the results for the white females in the present study were compared with DXA-derived body-composition data for reference populations in other countries. We conclude that reference values of total body composition for young females need to be ethnic-specific.