A new predictive equation for evaluating women body fat percentage and obesity-related cardiovascular disease risk.

BACKGROUND: Obesity represents a global public health problem due to its association with cardiovascular diseases and reduced lifespan. The most widely used classification of obesity is expressed as Body Mass Index (BMI); however, this formula is an imprecise adiposity measurement that ignores several important factors involved. Body Adiposity Index (BAI) was more recently proposed as an indirect evaluation of percentage body fat (PBF). PBF is a direct measure of person's relative body fat and a better predictor of obesity-related risk diseases than BMI and BAI. Since obesity and consequent diseases are considered epidemic, new accurate formulas for epidemiological studies are of interest to the scientific community. Because direct measurement of body composition could be quite expensive, the aims of our work were to analyse the distributions of PBF by Dual X-ray absorptiometry, and the creation of new predictive equation using only anthropometric measures that could be helpful to clinicians to assess easily body fat of female patients. METHODS/RESULTS: A sample of 1,031 Caucasian Italian women was recruited and BMI, BAI and PBF were evaluated. With the aim of developing a predictive model of PBF a multivariate regression model was fitted to observed data. CONCLUSIONS: The definition of universally recognized PBF by gender and age could have public health implications. In this study, we developed a new predictive PBF equation that does not require the use of medical instruments or skilled measurement techniques and that may be easily applicable to Italian women.

Association between -308 G/A TNF-α polymorphism and appendicular skeletal muscle mass index as a marker of sarcopenia in normal weight obese syndrome.

BACKGROUND AND AIM: Normal weight obese (NWO) syndrome is characterized by normal body mass index (BMI), but high amount of fat mass and reduced lean mass. We evaluated allelic frequency of the G/A -308 TNF-α polymorphism and prevalence of sarcopenia in NWO. METHODS: We enrolled 120 Italian healthy women, distinguished into 3 groups: normal weight (NW); NWO, and preobese-obese (PreOB/OB) and evaluated anthropometric parameters, body composition by dual X-ray absorptiometry, blood tests, and genotyping of G/A -308 TNF-α polymorphism. RESULTS: We found a positive association between sarcopenic obesity and -308 TNF-α polymorphism. All obese women were sarcopenic and were no carrier of mutation (G/G). Among all G/G, NWO showed significant differences in lean mass and total body lean mass (TBLean) with respect to NW and PreOB/OB (P < 0.001). Regarding appendicular skeletal muscle mass index values, 4.21% of NW were sarcopenic (50% G/G and 50% G/A); the same percentage was observed in NWO subjects (100% G/G). Moreover, 2.10% of PreOB/OB were sarcopenic and all were G/G. CONCLUSION: Our study suggests that TNF-α polymorphism contributes to sarcopenic obesity susceptibility, in association with body composition. This is the first study that shows the importance of TNF-α polymorphism to determine TBLean variation in NWO syndrome.

Body composition phenotype: Italian Mediterranean Diet and C677T MTHFR gene polymorphism interaction.

OBJECTIVES: Strategies to improve weight maintenance are focused on considering the genetic makeup and its interaction with dietary intake, with the aim to identify vulnerable individuals that will benefit from a variety of more personalized dietary recommendations. The aim of the study was to examine the impact of the C677T MTHFR gene Polymorphism on body composition changes induced by a balanced hypocaloric Italian Mediterannean diet (IMD). SUBJECTS AND METHODS: Participation in the study included a complete screening of anthropometry and body composition by Dual-energy X-ray absorptiometry (DXA), and a genotyping for the C677T MTHFR polymorphism. 70 Italian Caucasian obese were enrolled and 56 of them completed the screening at baseline and 12 weeks after the nutritional intervention. RESULTS: T(+) carriers had a higher content of Total Body Fat (TBFat), and Lean (TBLean), reflecting on higher weight and BMI, than T(-) carriers. After IMD, the 28.6% and 71.4% of total subjects decreased weight and TBFat (Kg), respectively. The relative changes were: delta % = -9.09±3.85 for weight; delta % = -15.79±8.51 for TBFat; delta % = -3.80±5.60 for TBLean. The 5.3% of subjects who reached the end point of intervention, and the 8.9% who reduced TBFat (%) below the cut-off of preobesity, were T(-) carriers. A loss of TBLean (Kg) was observed in the 5.1% and 23.5% of T(-) and T(+) carriers. CONCLUSIONS: MTHFR genetic variations analysis would be an innovative tool for the nutritional assessment, in order to predict the therapeutic response of obese subjects, in terms of fat and lean mass loss.

Effects of dark chocolate in a population of normal weight obese women: a pilot study.

BACKGROUND: Normal weight obese (NWO) syndrome is defined as an excessive body fat associated with a normal body mass index and characterized by a higher risk for cardiovascular morbidity and mortality. Recent studies have demonstrated that dark chocolate (DC) has beneficial effects in the prevention of cardiovascular diseases (CVD) due to its anti-inflammatory and antioxidant properties. AIM: The aim of the present study was to investigate the effects of DC consumption on lipid profile, inflammatory markers, biochemical parameters, and blood pressure, in NWO women. MATERIALS AND METHODS: 15 women affected by NWO syndrome, aged 20-40 years, were included in the study. After a DC-free washout period, subjects received DC (100 g/die) containing 70% cocoa for 7-days. Body composition by Dual energy-X-ray absorptiometry (DXA) was performed at baseline. Blood pressure, anthropometric measurements, biochemical parameters and plasma levels of some cytokines were measured before and after DC consumption. RESULTS: After DC consumption, we observed a significant increase in the HDL cholesterol level (Delta% = +10.41±13,53; p ≤ 0.05), a significant decrease of total cholesterol/HDL cholesterol ratio (Delta %= -11.45±7.03; p ≤ 0.05), LDL/HDL cholesterol ratio (Delta % = -11.70±8.91; p ≤ 0.05), and interleukin-1 receptor antagonist (IL-1Ra) (Delta % = -32.99±3.84; p ≤ 0.05). In addition, a reduction in abdomen circumference was observed. We also found a positive correlation between changes in atherogenic indices, and IL-1Ra, abdomen reduction. CONCLUSIONS: Our findings suggest that regular consumption of DC could be useful in maintaining a good atherogenic profile, due to the favourable effects on HDL cholesterol, lipoprotein ratios and inflammation markers.

Body composition changes after laparoscopic adjustable gastric banding: what is the role of -174G>C interleukin-6 promoter gene polymorphism in the therapeutic strategy?

BACKGROUND: There is growing evidence that interleukin-6 (IL-6) is linked to the regulation of fat mass (FM). Our previous data define the common -174G>C IL-6 polymorphism as a marker for 'vulnerable' individuals at risk of age- and obesity-related diseases. An association between -174G>C IL-6 polymorphism and weight loss after bariatric surgery has been demonstrated. OBJECTIVE: We investigated the impact of -174G>C IL-6 polymorphism on weight loss, body composition, fluid distribution and cardiometabolic changes in obese subjects, after laparoscopic adjustable gastric banding (LAGB) surgery. DESIGN AND OUTCOME MEASURES: A total of 40 obese subjects were studied at baseline and at 6 months follow-up after LAGB surgery. Cardiometabolic and genetic assessment of -174G>C IL-6 polymorphism, anthropometric, body composition and fluid distribution analysis were performed. RESULTS: After LAGB surgery, significant reductions in weight (Δ%=-11.66 ± 7.78, P<0.001), body mass index (P<0.001), total and trunk FM (kg, %) (Δ% of total FM=-22.22 ± 12.15, P<0.01), bone mineral density (T-score) (P<0.001), resting metabolic rate (RMR) (P<0.01), and total body water and intracellular water (TBW, ICW) (P<0.05) were observed. At baseline, C(-) carriers of IL-6 polymorphism had a significantly higher RMR (P<0.05), free FM (kg), but less total and trunk FM (%), higher body cell mass (BCM), content of TBW (L) and ECW (extracellular water)/ICW ratio compared with C(+) carriers (P<0.001). After LAGB, C(+) carriers had a significantly stronger reduction of total FM (kg), but lower bone density, compared with C(-) carriers (P<0.05). CONCLUSIONS: Beyond the relationship between -174G>C IL-6 polymorphism and body composition, this study provides first evidence about the association of IL-6 variant with fluid distribution, at baseline, and FM and bone density loss in obese subjects at 6 months follow-up after LAGB surgery. LAGB was less effective if the subjects were carrying risk genotypes, C(-) carriers, for obesity, suggesting a role of genetic variations on bariatric surgery outcomes.

New trends in nutritional status assessment of cancer patients.

BACKGROUND: Nutritional status assessment and support should be considered a valuable measure within the overall oncology strategy. Despite extensive research in the field of clinical nutrition, definite guidelines to base rational nutritional assessment and support in cancer patients are still debated. This review examines different approaches to nutritional status in cancer patients. DESIGN: The assessment of nutritional status is usually based on anthropometric measures, biochemical or laboratory tests, clinical indicators and dietary assessment. At present, body composition (BC) is rarely measured in the clinical setting because it is thought to be too unmanageable and time-consuming. However, using new technologies, the estimation of fat, lean and body fluids, that is significant in the management of nutrition therapies in oncology, has become easy. The present study evaluates the different methods of nutrition assessment today available, especially body composition (BC) measurements. Furthermore, nutrition assessment, relevance of nutritional support and choice of nutritional strategy, in surgical patients, are discussed. DISCUSSION: Given the clinical relevance of nutritional intervention in patients' quality of life, the nutritional status assessment has a key role in oncological and surgical practice and should include BC assessment in order to tailor nutritional treatment to patients' individual requirements. Furthermore, administration of the supplemented diet before and after surgery seemed to be the best strategy to reduce complications and length of hospital stay.

Multicompartment model to assess body composition in professional water polo players.

AIM: The aim of this study was to compare differences between skinfold thicknesses (SK), bioelectrical impedance analysis (BIA), a 2-compartment model (2C), and 2, 3-compartment models (3C) of percent body fat (%BF) assessment with a 4-compartment model (4C) in professional water polo athletes. METHODS: Ten male subjects, 18 to 29 years of age, participated in this study. Under water weighing, deuterium dilution, and dual-energy X-ray absorptiometry (DXA) were used to provide the required values for the models. The two, 3C models used were established by Withers et al. (3C-W) and by the DXA manufacturers (3C-DXA). 4C was also established by Withers et al. RESULTS: There were no significant differences between 2C, 3C-W, and 3C-DXA when compared with 4C (criterion model). There were no significant differences between 2C and 3C-W. %BF was significantly greater using 2C compared with 3C-DXA. %BF derived from SK and BIA were significantly greater than all other METHODS: 4C was best correlated with 3C-W (R2=0.998), followed by 2C (R2=0.806), 3C-DXA (R2=0.5071), SK (R2=0.2945), and BIA (R2=0.2377). CONCLUSION: We conclude that 2C and 3C-W assess %BF equally as well as 4C; however, SK and BIA significantly over-estimated %BF in water polo athletes.

Body composition differences in adolescent female athletes and anorexic patients.

Osteopenia is a frequent complication affecting adolescent girls with anorexia nervosa (AN). Moreover, female athletes suffering from eating disorders can be affected by premature osteoporotic fractures. The aim of this study was to examine bone mineral content (BMC) and bone mineral density (BMD) in three groups of adolescent females. Anthropometric and body composition measurements were performed on 22 adolescent females (age+/-SD=15.6+/-1.4 years) divided into groups: athletes ( n=8), patients with AN ( n=8) and age-height matched control subjects ( n=6). Body weight and body mass index were significantly lower ( p<0.01) in athletes and AN patients compared with healthy controls. BMC and BMD were lower ( p<0.01) for AN patients and athletes compared with healthy controls; AN patients had the lowest BMC value. Athletes had higher lean body mass values compared with AN patients and healthy controls. These results suggest that the effects of eating disorders, specifically BMC loss, could be attenuated by physical activity.

Analysis of body water compartments after a short sauna bath using bioelectric impedance analysis.

Studies have suggested that long-term sauna bathing may lower blood pressure in persons with hypertension by causing a direct loss of extracellular water and plasma minerals. The objective of the present study was to evaluate the effect of short-term sauna bathing on body water compartments as estimated by bioelectric impedance analysis (BIA). We recruited 15 men [mean age (+/-SD) of 23.93+/-5.12 years and mean body mass index (BMI) of 23.25+/-2.84 kg/m(2)] and 10 women matched for age and BMI. Total body resistance, reactance, and impedance were measured for all participants using BIA, at baseline, after a short sauna bath, and after a rest period. Total, extracellular, and intracellular water compartments were calculated using BIA formulae. There were no significant differences for any of the body water compartments when comparing the measurements taken before and after the sauna bath and after the rest period. However, it remains to be determined whether or not BIA is sensitive to rapid changes in water volume.

Use of foot-to-foot bioelectrical impedance analysis in children.

The aim of this study was to compare two methods of measuring body composition in children aged 6-10 years: with a traditional bioelectrical impedance analyser and a foot-to-foot impedance device. In 117 subjects (55 girls, 62 boys), bioelectrical impedance was measured using a Xitron 4000 device and a foot-to-foot impedance instrument (Rowenta); body fat mass and fat-free mass were then calculated and comparisons between means were performed using appropriate statistical tests.

Total body water estimation using bioelectrical impedance: a meta-analysis of the data available in the literature.

Bioelectric impedance analysis (BIA) is commonly used in clinical settings and field studies for estimating total, extracellular, and intracellular water compartments. The objective of the present study was to carry out a meta-analysis of published reports in which total body water (TBW) was estimated using BIA techniques and comparisons were made with reference values. We identified 16 reports conducted among healthy and obese adults and individuals with chronic renal failure. Based on the weighted mean difference, we found that those studies using only multi-frequency BIA did not significantly overestimate the TBW compared with the reference values. Thus, among BIA techniques, multi-frequency BIA seems to be a more accurate method for estimating the TBW compartment for healthy and obese adults and for those with chronic renal failure.

Physical activity energy expenditure measured using a portable telemetric device in comparison with a mass spectrometer.

BACKGROUND: Several studies have evaluated the accuracy of portable metabolic gas analysis systems, which measure physical activity energy expenditure. Since the Cosmed K2 telemetric system, two K4 devices (RQ and b2) have been developed. OBJECTIVE: To compare measurements using the Cosmed K4 RQ with measurements by a traditional method (mass spectrometer) for a sample of healthy subjects performing physical exercise of various intensities. METHODS: Nine healthy male footballers (mean (SD) age 18.3 (2.2) years) performed an incremental exercise running test from 8 km/h to exhaustion, with an increase of 2 km/h for each level of the test protocol. The expired air was collected simultaneously using the Cosmed K4 RQ and Airspec QP9000 mass spectrometer. Oxygen consumption (VO2) and carbon dioxide production (VCO2) were measured at rest and at each exercise intensity. RESULTS: No significant differences were found between VO2 and VCO2 measured by the two instruments, at rest or during exercise. CONCLUSIONS: The application of the Cosmed K4 RQ system for VO2 and VCO2 measurements at rest and during both submaximal and maximal exercise may be of interest to sport physiologists, nutritionists, and doctors.

The impact of body-weight components on forced spirometry in healthy italians.

Many studies have investigated lung function in relation to age and height among Caucasians, however, most of these studies did not consider the individual components of body weight. The objective of the present study was to study the effect of body weight components [bone-free lean body mass (BF-LBM), bone mineral content (BMC), and fat mass (FM)] measured by dual x-ray absorptiometry (DXA) on the lung-function variables (FVC, FEV1, and PEF) and to derive prediction equations for these variables in healthy adult Italians. Dynamic spirometric tests and body composition analysis by DXA were performed on 58 nonsmoking males, mean age ( +/-SE) 26.72 +/- 1.98 years and BMI 25.51 +/- 0.64 kg/m2, and 60 nonsmoking females matched for age and BMI (29.61 +/- 1.65 years and 26.45 +/- 1.05 kg/m2, respectively). Bivariate linear regression analysis showed the variables age, height, BF-LBM, BMC, and the interaction term BF-LBM*Height, but not weight and FM, to correlate significantly with lung-function variables for males and for females separately. Multiple linear regression analysis showed that sex, age, height, and BF-LBM*Height were significantly associated with FVC, FEV1, and PEF. The prediction equations developed for FVC, FEV1, and PEF on the basis of the independent variables i.e. sex, age (y), height (m), and BF-LBM*Height (kg. m) had a significantly higher cumulative correlation coefficient and a lower SEE compared with those based on age and height only. The present report suggests that the BF-LBM, expressed independently from height, can be considered for predicting lung-function variables.

Use of quality control indices in moderately hypocaloric Mediterranean diet for treatment of obesity.

A large number of studies have been published on very-low calorie diets and markedly hypocaloric dietary regimens for treatment of obesity. However, scanty data are available on moderately hypocaloric diets based on the Mediterranean diet model. We evaluated the efficacy and safety of a moderately hypocaloric Mediterranean diet (MHMD) by assessing changes in body composition and in metabolic profile in 19 obese women, aged 32+/-4 years, body weight 84.7+/-9.6 kg, body mass index (BMI) 33.67+/-2.61 kg/m2. The energy content of the diet (mean 6.5 MJ/day) matched the resting metabolic rate and its content in macronutrients (55% carbohydrate, 25% fat, 20% protein, 30 g fibre) was based on the Italian Recommended Dietary Allowances (LARN). Based on the Mediterranean diet model, available nutritional indices like the animal/vegetable protein ratio, the Cholesterol/Saturated Fat Index, the Glycaemic Index, the Atherogenic Index, the Thrombogenic Index and the Mediterranean Adequacy Index were taken into account in elaborating diets. At baseline and after 2 months, body composition by dual energy X-ray absorptiometry, metabolic profile, uric acid, fibrinogen and oral glucose tolerance test (OGTT) were assessed. Following MHMD, body weight decreased to 78.1+/-10.5 kg and BMI to 31.18+/-2.74 kg/m2. Total (-4.9+/-0.9 kg) and segmental fat mass decreased, no significant loss of total and segmental lean body mass was observed. No decrease of fasting blood glucose (5.05+/-0.45 vs 4.98+/-0.43 mmol/l, NS), of the area under the curve (AUC) for glucose (29.50+/-6.24 vs 28.07+/-5.29, NS) as well as of HDL-cholesterol (1.30+/-0.30 vs 1.33+/-0.33 mmol/l, NS) and of triglycerides (1.70+/-1.00 vs 1.46+/-0.66 mmol/l, NS) was observed. However, a significant decrease of basal insulin (11.48+/-6.77 vs 8.07+/-4.17 mU/ml, p<0.01) as well as of the AUC for insulin (263+/-118 vs 208+/-82,p<0.005), of total (5.40+/-1.04 vs 4.97+/-0.92 mmol/l,p<0.05) and LDL-cholesterol (3.36+/-1.07 vs 2.90+/-0.74 mmol/l,p<0.005), of uric acid (0.30+/-0.06 vs 0.28+/-0.05 mmol/l,p<0.01) and fibrinogen (359+/-78 vs 324+/-87 mg/100 ml, p<0.0001) was observed. In conclusion, MHMD prevents loss of fat-free mass and improves metabolic parameters in obese people. We advocate a wider use of nutritional indices and body composition assessment as tools for quality control of hypocaloric diets.

Food habits in a southern Italian town (Nicotera) in 1960 and 1996: still a reference Italian Mediterranean diet?

BACKGROUND: A follow-up analysis of cohorts surveyed in the "Seven Countries Study" has provided increasing evidence of an association between diet and morbidity or mortality from coronary heart disease (CHD) and cancer. The effects of the "Mediterranean diet" on mortality is still evident in Italy, where food patterns differ significantly in different geographical areas. OBJECTIVE: To examine differences in food habits in Nicotera, one of the Italian rural areas of the Seven Countries Study, between 1960 and 1996. METHODS: In 1996, 80 subjects, 37 females and 43 males, aged 40-59 years, were examined in Nicotera assessing food intake by means of a semiquantitative questionnaire of food frequency, validated for the Italian population. In 1960, food intake of a sample of Nicotera subjects was assessed by weighed record method for three seasons. RESULTS: Food choices differed markedly between 1960 and 1996. Consumption of animal foods increased, as did that of cakes, pies and cookies and sweet beverages in both male and female groups; an increase of alcoholic beverages was observed only in females. CONCLUSIONS: In 1960, Nicotera inhabitants were following a diet defined as a "reference Italian Mediterranean diet", but by 1996 the Nicotera diet approached that of an average Italian diet, whose characteristics fall short of a true Mediterranean diet. This change in dietary habits may be responsible for an increased risk of CHD and cancer in the general population in the absence of other factors.

Body composition measurement in highly trained male athletes. A comparison of three methods.

BACKGROUND: The purpose of the present study was to evaluate the differences in the body composition estimate of highly trained male athletes by three different methods: dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA) and skinfold thickness measurement (SFT). METHODS: The study occurred during a non-intensive training period. The measurements were performed at the Human Physiology laboratory. PARTICIPANTS: forty-three male athletes (19 waterpolo, 9 judo, 15 karate) who exercised regularly at least three hours per day, six days per week. MEASUREMENTS: DXA, BIA and SFT measurements of percentage fat mass (%FM) and the amount of fat-free mass (FFM) were performed. STATISTICAL ANALYSES: the different %FM estimates by the three methods were compared using a one-way ANOVA, with posthoc Bonferroni test when values were significantly different. The same test was used to compare FFM values. The coefficient of variation (CV%=100xSD/mean) was calculated for each methods. Methodological differences among the various methods were analysed with the method of Bland-Altman. RESULTS: ANOVA test showed significant differences among the three methods. In particular, DXA significantly (p<0.001) overestimated %FM (12.4+/-4.1%) and underestimate FFM (67.0+/-6.9 kg) respect to SFT (7.8+/-0.9 % and 71.0+/-8.2 kg) and BIA (9.9+/-1.4% and 69.4+/-7.9 kg). Also Bland-Altman comparison among the estimates indicated wide differences between methods. CONCLUSIONS: DXA provides different body composition estimates than those derived from skinfold thickness measurement and BIA, so that the methods should not be used interchangeably.

Comparison of different techniques to measure body composition in moderately active adolescents.

OBJECTIVE: To evaluate the differences in the estimate of body fat percentage (%FM) and the amount (kg) of fat free mass (FFM) by different methods in 26 moderately active adolescents very similar in age, body fatness, and training status. METHODS: Mean (SD) age was 16.7 (0.9) years, height was 177.0 (5.1) cm, and weight 68.0 (5.2) kg. %FM was assessed using dual-energy x ray absorptiometry (DXA) and two skinfold prediction equations: that of Slaughter et al (%FM Sla) and that of Deurenberg et al (%FM Deu). In the same way, FFM was measured using DXA and different impedance equations: those of Suprasongsin et al (FFM Sup), Schaefer et al (FFM Sch), Houtkooper et al (FFM Hou), and Deurenberg et al (FFM Deu). To determine the interchangeability of the different methods of measuring %FM and FFM, one way analysis of variance, standard error (SE), and coefficient of variation (CV%) ((SD/mean) x 100) were used. RESULTS: On average, no significant statistical differences were observed between the values determined for %FM: DXA value, 11.7 (5.4%); %FM Sla, 10.9 (4.0)%; %FM Deu, 11.5 (2.3)%. On the other hand, SE and CV% between each pair of the three methods used showed very large variability. With regard to the measurement or prediction of FFM, the mean value measured by DXA was significantly higher than that predicted by the equation of Sch (+7.2 kg, p < 0.001), Deu (+3.2 kg, p < 0.001), and Hou (+2.6 kg, p < 0.001), whereas it was lower than that predicted by the equation of Sup (-1.6 kg, p < 0.05). The Hou and Deu values were the only two that, on average, did not differ in a statistically significant way, although they showed the highest CV%. CONCLUSIONS: In our sample of moderately active adolescents the estimated values for %FM and FFM appear to be highly dependent on method.

Fat-free mass by bioelectrical impedance vs dual-energy X-ray absorptiometry (DXA).

Body composition (BC) assessment is a useful tool for a careful evaluation of nutrition status. Bioelectrical impedance analysis (BIA) is a safe, low-cost and reliable method for BC assessment. For epidemiological and clinical research in children, paediatric-age specific formula for fat-free mass (FFM) prediction from BIA is needed. Thus, in 35 children (age 7.7-13.0 years) with different levels of body fatness (relative weight for age 70.6-133.8%), FFM was calculated from dual-energy X-ray absorptiometry (DXA). A regression equation from BIA and DXA data was elaborated. The impedance index (ZI = height2/bioelectrical impedance) was the strongest predictor of FFM, explaining 89% of its variance. However, the variance increased to 96% when body weight was added with ZI in the regression model. No variable, including sex and age, contributed to the prediction of FFM in the presence of ZI and body weight. The regression formula [FFM = 2.330 + 0.588 ZI (cm2/omega) + 0.211 Weight (kg) (r = 0.96, SEE = 1.0 kg)], allows a reliable prediction of FFM in children from body impedance values.

Identification by differential display of transcripts regulated during hematopoietic differentiation.

The polymerase chain reaction-based differential display method (DDRT-PCR) was used to identify mRNAs differentially expressed during the maturation of human CD34+ progenitor cells stimulated to differentiate in vitro towards granulomonocytic or erythroid lineages with a mixture of hemopoietins (kit ligand + interleukin 3 + GM-CSF in the absence or presence of erythropoietin, respectively). Three cDNA transcripts (B32, B41, and B56) display differential expression during cytokine-induced maturation of CD34+ cells. These clones have no homology with already-described sequences. Primer extension cofirmed the presence of the corresponding mRNA. The levels of mRNA corresponding to B32 are enhanced in the later phases of the granulomonocytic as well as in the erythroid differentiation of CD34+ cells. The mRNA identified by B41 was induced by a late stage in only granulomonocytic differentiation of CD34+ cells. The mRNA corresponding to B56 was instead present in nonstimulated CD34+ cells, declined in the early stages of differentiation, and reappeared at later stages in cells treated with both combinations of cytokines. Expression of these genes was detected in a number of acute myelogenous leukemias, as well as in some leukemic cell lines. B32 and B41 were downregulated in KG-1 cells induced to differentiate towards the monocytic lineage, whereas the levels of B56 were unchanged. In K562 cells, clones B41 and B56 were downregulated only in the late phases of PMA-induced megakaryocytic differentiation and during erythroid differentiation. B32 was rapidly downregulated when K562 cells were induced to differentiate towards either megakaryocytic or erythroid phenotypes. These transcripts represent novel hematopoietic cDNAs that should prove of value for the study of human blood cells and their disorders.