Mass-zero constrained molecular dynamics for electrode charges in simulations of electrochemical systems.

Classical molecular dynamics simulations have recently become a standard tool for the study of electrochemical systems. State-of-the-art approaches represent the electrodes as perfect conductors, modeling their responses to the charge distribution of electrolytes via the so-called fluctuating charge model. These fluctuating charges are additional degrees of freedom that, in a Born-Oppenheimer spirit, adapt instantaneously to changes in the environment to keep each electrode at a constant potential. Here, we show that this model can be treated in the framework of constrained molecular dynamics, leading to a symplectic and time-reversible algorithm for the evolution of all the degrees of freedom of the system. The computational cost and the accuracy of the new method are similar to current alternative implementations of the model. The advantage lies in the accuracy and long term stability guaranteed by the formal properties of the algorithm and in the possibility to systematically introduce additional kinematic conditions of arbitrary number and form. We illustrate the performance of the constrained dynamics approach by enforcing the electroneutrality of the electrodes in a simple capacitor consisting of two graphite electrodes separated by a slab of liquid water.

Adherence to the Mediterranean Diet in children and adolescents: A systematic review.

BACKGROUND AND AIM: A decreased adherence to the Mediterranean Diet (MD) may be related to a rise in chronic non-communicable diseases from childhood onward. The aim of this systematic review was to summarize the available literature regarding MD adherence in children and adolescents, and focusing, more specifically, on the association of MD adherence with demographic and anthropometric variables, body composition, lifestyle, and diet adequacy. METHODS AND RESULTS: A search of scientific literature was carried out on PUBMED, SCOPUS, Clinical Trials Results, Google Scholar, and British Library Inside for studies published in the last 20 years. Fifty-eight papers were finally included according to the following criteria: MD adherence evaluated through a quantifying score or index, age 2-20 years, sample size >200 participants, observational or intervention studies regarding the general population. The KIDMED index was the most widely used scoring system. MD adherence widely varied within the Mediterranean countries for both children and adolescents, with also large differences among various European countries, while few data are available for non-Mediterranean countries. Most of the eligible studies showed that MD adherence was directly associated with physical activity (and possibly with diet adequacy) and inversely with sedentary behavior, while the results for gender, age, socioeconomic status and weight status were not consistent. CONCLUSIONS: Further validation of MD indexes in terms of reproducibility and consistency with the MD is needed. At the same time, more prospective cohort and intervention studies may better elucidate the relationships of MD adherence with behavioral and health outcomes.

Protective role of the Mediterranean diet on several cardiovascular risk factors: evidence from Sicily, southern Italy.

BACKGROUND AND AIMS: Epidemiological studies conducted in European countries demonstrated that the adoption of a Mediterranean diet protect against clustered risk factors but those evaluating such benefits specifically in southern Italy are scarce. Thus, the aim of this study was to assess the association between the adherence to the Mediterranean diet and cardiovascular risk factors obesity, diabetes, and hypertension. METHODS AND RESULTS: A cross-sectional population-based survey including 3090 subjects was conducted in Sicily, southern Italy. Food intake was evaluated through a validated food frequency questionnaire and adherence to the dietary pattern was assessed using the MedDietScore. Linear and logistic regression models were performed to estimate odds ratios (ORs) and respective confidence intervals (CIs). After adjusting for confounding factors such as age and gender, participants in the highest tertile of the MedDietScore were less likely to be obese (OR 0.35, 95% CI: 0.24-0.51), hypertensive (OR 0.73, 95% CI: 0.55-0.97), and diabetic (OR 0.43, 95% CI: 0.24-0.77). Linear inverse relation between the MedDietScore and BMI (r(2) = 0.34, P < 0.001), waist circumference (r(2) = 0.17, P < 0.001), and waist-to-hip ratio (r(2) = 0.06, P < 0.001) was found. CONCLUSION: Despite the prevalence rates of nutrition-related diseases are high in Sicily, greater adherence to the Mediterranean dietary pattern is still associated with a better health status.

Population based strategy for dietary salt intake reduction: Italian initiatives in the European framework.

Excess dietary sodium chloride (salt) intake is etiologically related to hypertension and cardiovascular disease (CVD). Moderate reduction of salt intake reduces blood pressure (BP) and is expected to contribute to reduce the risk of CVD. Previous community-based trials to reduce BP by means of salt reduction were very successful. The initial positive results of national strategies of dietary salt intake reduction in several European countries, driven by the initiative of the World Health Organisation (WHO) and non-governmental organisations such as the World Action of Salt and Health (WASH), have paved the way for action in other European Union (EU) member states. In Italy, several initiatives aiming at reduction of salt intake at the population level have been recently undertaken. These initiatives include i) the evaluation of current dietary habits promoted by the Working Group for Dietary Salt Reduction in Italy (GIRCSI); ii) the chemical analysis of the bread salt content, a major source of sodium intake in Italy, and the agreement between the bakers' associations and the Ministry of Health for a gradual reduction of the bread salt content; iii) the implementation of educational campaigns to increase population awareness, iv) the involvement of the food catering system. In the immediate future, food reformulation must be extended to other food categories in collaboration with industry, foods' salt targets ought to be defined, the food labelling system must be improved and population salt awareness must be further increased through educational campaigns. The GIRCSI Working Group is committed to pursue these objectives.

Development of a tomato-based food for special medical purposes as therapy adjuvant for patients with HCV infection.

OBJECTIVE: The present study aimed to develop a food for special medical purposes (FSMP) and to assess its efficacy as adjuvant therapy in patients with chronic hepatitis C virus (HCV). DESIGN: Open randomized clinical trials with a tomato-based FSMP used as adjuvant treatment to the pharmacological therapy with pegilated interferon and ribavirin. SUBJECTS: Eight healthy volunteers and 39 HCV patients. INTERVENTIONS: For the bioavailability study, healthy subjects consumed 100 g/die FSMP for a week and their serum carotenoid profile at baseline, after the week of administration and 7 days later was determined. The same quantity of FSMP for 6 months by 20 of the 39 HCV patients was consumed in the clinical trial. Serum transaminase, haemoglobin (Hb) and hydroperoxide concentrations during the therapy were monitored in all patients. RESULTS: FSMP consumption caused a fourfold increase of lycopene serum concentration in healthy subjects. A significant increase of carotenoids after 1 month of consumption also in patients with HCV was recorded. Transaminase and Hb serum levels, as well as therapeutic response, were not influenced by FSMP. The decrease in serum hydroperoxides was independent from FSMP consumption in long-term responder patients, whereas nonresponder (NR) patients of FSMP group showed higher reductions than NR patients of Control group. CONCLUSIONS: The FSMP was effective in improving carotenoid status in healthy subjects. In HCV patients, it did not influence the therapeutic response, but it prevented carotenoid serum depletion and it was effective in improving the oxidative status during antiviral therapy in NR patients.

Raw BIA variables are predictors of muscle strength in patients with chronic obstructive pulmonary disease.

BACKGROUND/OBJECTIVES: Although loss of fat-free mass (FFM) and reduced muscle strength are highly prevalent in chronic obstructive pulmonary disease (COPD), only few data are available on the relationships of handgrip strength (HGS) and respiratory muscle strength with body composition in such disease. In particular, we aimed to assess whether raw bioelectrical impedance (BIA) variables were independent predictors of muscle strength in COPD patients, possibly more significant than anthropometric variables and BIA-based estimates of FFM. SUBJECTS/METHODS: Two hundred and thirty-seven COPD patients (161 males and 76 females) underwent respiratory, anthropometric, BIA, HGS and respiratory muscle strength (maximum inspiratory or expiratory pressure=MIP and MEP) measurements. Bioimpedance index (BI index=height square/whole-body impedance) and phase angle (PhA) were considered as raw BIA variables. FFM was estimated using three disease-specific BIA equations. RESULTS: In COPD patients a stronger correlation was observed between HGS and PhA compared to the ones with anthropometric variables or FFM estimates. Multiple regression analysis showed that combining BI index and PhA (plus age in male patients) accounted for 50.2% and 42.6% of the variance in HGS in male and female patients, respectively. Similarly, BI index and PhA emerged as predictors of both MIP and MEP in males, while in females MIP was related only to PhA and MEP only to BI index. CONCLUSIONS: Raw BIA variables are independent and valuable predictors of HGS and respiratory muscle strength in COPD patients. BI index and PhA could provide useful information for evaluating body composition and better assessing muscle strength and physical fitness in COPD.

Relations of left ventricular geometry and function to body composition in children with high casual blood pressure.

To determine whether abnormal casual blood pressure (BP) is associated with left ventricular (LV) abnormalities in children, 190 6- to 11-year-old children (77 girls, 113 boys) were studied at a school site in Naples, Italy, by limited echocardiography and bioelectric impedance to calculate fat-free body mass (FFM). Single-visit BP measurements (defined as casual BP) were high (based on the Italian tables of BP) in 34 children (18%; 9 girls, 25 boys; 133+/-8/81+/-10 mm Hg) and obesity was present in 44 (23%; 15 girls, 29 boys). Sex- and age-independent risk of high casual BP value was 2.9-fold (odds ratio) greater in obese than in normal-weight children (95% confidence interval, 1.3 to 6.5; P<.01). LV mass (as both absolute value and normalized for height or FFM) was higher and relative wall thickness increased in children with high casual BP (all P<.01). Prevalence of LV hypertrophy was 21% among children with high casual BP (P<.004 versus 4.3% in normal group). Risk of LV hypertrophy was 5.5-fold higher in the presence of high casual BP (P<.004), whereas obesity, age, and sex did not have independent effects. Endocardial shortening was slightly higher in children with high casual BP (36.8+/-8.2%) than in children with normal BP (34.3+/-4.8%, P<.02), whereas midwall shortening was identical in the two groups (20%). Both endocardial shortening and midwall shortening were negatively related to end-systolic stress (r=-.62, SEE=3.8% and r=-.32, SEE=2.4% in normal children). Shortening as a percentage of predicted from wall stress was increased in children with high casual BP at the endocardial level (P<.001), whereas it was normal at the midwall. Therefore, (1) casual detection of high BP in school children is associated with LV geometric abnormalities similar to those found in adults with sustained hypertension (LV hypertrophy, concentric pattern); (2) similar to in adult hypertension, endocardial chamber function in children is supranormal; and (3) in contrast to findings in adults, midwall shortening is normal in children with high casual BP.

Postprandial thermogenesis in lean and obese subjects after meals supplemented with medium-chain and long-chain triglycerides.

The thermic effect of medium-chain triglycerides (MCTs) was studied in six lean and six obese young males by evaluating postprandial thermogenesis (PPT) after the ingestion of mixed meals containing either 38 g long-chain triglycerides (LCTs) or 30 g MCTs plus 8 g LCTs. Postabsorptive resting metabolic rate (RMR) was higher (P less than 0.05) in the obese individuals than in the lean ones. PPT, evaluated as 6-h incremental areas above RMR, was greater (P less than 0.05) in both groups after meals containing MCTs. The thermic effect of MCTs was 119.7 +/- 33.9 and 144.7 +/- 48.8 kJ/6 h in the lean and the obese subjects, respectively. The postprandial response of glucose, insulin, and free fatty acids did not depend on the type of oil contained in the meal. Our study shows that PPT is enhanced in both lean and obese subjects when LCTs in a mixed meal are replaced with MCTs.

Albumin and labile-protein serum concentrations during very-low-calorie diets with different compositions.

Circulating concentrations of albumin and the labile proteins prealbumin (PA) and retinol-binding protein (RBP) were evaluated over 20 d in five groups of obese patients. The patients were given four types of very-low-calorie diets (VLCDs) (less than 500 kcal/d) that provided different amounts of protein or carbohydrate (CHO) plus protein and a conventional 1200-kcal/d hypocaloric diet. Serum albumin concentrations did not vary significantly during any of the diets whereas PA and RBP remained unchanged only during the conventional 1200-kcal/d diet. Similar and significant decreases of serum PA and RBP were observed during the VLCDs studied. The molar ratio of RBP to PA did not vary during dieting. Thus, when less than 500 kcal/d are given, changes of serum short-half-life visceral proteins are not affected by either the addition of CHO to protein or the changes in protein intake. Moreover, serum albumin concentration and RBP/PA do not vary during VLCDs.

Changes in the glycosylation pattern of circulating gonadotropins after acute administration of gonadotropin-releasing hormone in patients with anorexia nervosa.

To study the involvement of gonadotropin-releasing hormone (GnRH) in glycosylation of circulating gonadotropin isoforms in anorexia nervosa (AN), 14 amenorrhoic patients with AN, 14 age-matched volunteers in early follicular phase, and five normal-weight re-fed patients with AN were investigated under baseline conditions and after acute administration of GnRH. Plasma gonadotropins were assayed using IRMA before and after concanavalin A affinity chromatography. Baseline plasma gonadotropin levels were lower for both AN and re-fed AN patients than in controls (P<0.005). The increase in FSH and LH after GnRH administration was lower than in controls for AN (P<0.005) and re-fed AN (P<0.005 and P<0.05 respectively) patients. Percentages of total gonadotropin not bound to concanavalin A (complex carbohydrate chains) under baseline conditions were higher in patients with AN than in controls (P<0.005) but decreased after GnRH administration (P<0.001). In re-fed AN patients, the percentage of unbound FSH was higher than in controls (P<0.05), and decreased after GnRH administration (P<0.001), whereas the percentages of unbound LH were not significantly different from controls either before or after GnRH administration. These data suggest that: (a) the acute administration of GnRH induces quantitative and qualitative changes in circulating gonadotropin isoforms in both normal controls and AN patients; (b) during recovery the LH response in re-fed AN patients is associated with a glycosylation pattern that is the same as that for controls.

Altered glycosylation of pituitary gonadotropins in anorexia nervosa: an alternative explanation for amenorrhea.

To investigate the relevance of glycoprotein polymorphism to gonadotropin bioactivity in vivo, plasma follicle-stimulating hormone (FSH) and luteinizing hormone (LH), 17 beta-estradiol (E2), testosterone and sex hormone binding globulin (SHBG) levels in 17 amenorrheic women affected with anorexia nervosa (14-29 years) and 10 age-matched normally cycling women were evaluated. Plasma FSH and LH levels were assayed using radioimmunoassay (RIA) and immunoradiometric assay (IRMA) methods, before and after concanavalin A-Sepharose (Con A) affinity chromatography. Significant RIA-IRMA differences in FSH and LH plasma values were present only in women with anorexia nervosa (p < 0.005). Moreover, in these patients both FSH and LH showed a reduced binding to the Con A, expressed as a percentage of unbound, suggesting altered glycosylation of these moieties. In conclusion, these findings hypothesize the involvement of glycosylation polymorphism in RIA-IRMA differences; support the usefulness of both RIA and IRMA methods in FSH and LH evaluation, before and after Con A chromatography; and suggest a new pathogenetic pathway to explain amenorrhea in anorexia nervosa.

Predicted and measured resting energy expenditure in healthy young women.

Basal energy expenditure (BEE) was either measured by indirect calorimetry or predicted by different formulae in 104 young women: 74 lean and overweight subjects (normal weight, NWt) and 30 obese subjects. The predictive equations were based on weight alone (Owen, FAO-1, Schofield-1) or on weight and height (Harris-Benedict, Mifflin, Kleiber, and again FAO-2 and Schofield-2). With the exception of the Owen equation all the equations over-estimated measured BEE in both study groups. The ratio between measured and predicted value (% MP) varied between 102.3 (Owen) and 87.7 (Kleiber) in the NWt subjects and between 113.2 (Owen) and 89.3 (Schofield-1) in the obese subjects. The range including 95% of the predicted-measured differences (PMdiff) was larger than 1700 kJ/d in the NWt group and 2300 kJ/d in the obese group. In both study groups most of the equations showed a significant relationship between PMdiff and/or % MP with body weight and the magnitude of BEE. In conclusion, these equations are of little help in predicting BEE in a single subject and should be used with caution when assessing energy requirements in populations or groups of subjects.

Use and abuse of albumin: a survey of clinical records from an internal medicine ward.

BACKGROUND AND AIMS: This study was to review albumin prescriptions and indications in 4122 patients hospitalized in internal medicine wards in the years 1996, 1998 and 1999, before and after the ad hoc regulations issued in 1997 by the Italian Ministry of Health. METHODS: In 1996 (n=63), 1998 (n=59) and 1999 (n=55) 177 of these patients (4.3%) were given i.v. albumin. RESULTS: 161 (91%) of them had serum albumin values of <3.5 g/dl, while in only 36% were these values <2.5 g/dl. CONCLUSION: In the majority of cases albumin was erroneously prescribed, often to enhance diuretic efficacy or in protein energy malnutrition. Its prescription has not been influenced by the new recommendations.

Bioimpedance analysis and resting energy expenditure in undernourished and refed anorectic patients.

Anthropometry, bioimpedance analysis (BIA) and resting energy expenditure (REE) were evaluated in young female patients affected by anorexia nervosa who were either severely malnourished (MnA) or already refed (RfA) and in a control group of healthy young women (WnC). Fat-free mass (FFM) and fat mass (FM), evaluated from skinfold thickness, were severely decreased in the MnA group while they were very similar in the RfA group and in the WnC group. With respect to BIA parameters, impedance (Z) was significantly higher in absolute terms in the MnA but lower than in the other groups when expressed as specific impedance, i.e. after normalization for both FFM and height. Phase angle significantly differed between the three groups, being significantly (P < 0.01) lower in the MnA (3.70 +/- 0.83 degrees) and the RfA (4.36 +/- 0.82) than in the WnC (5.17 +/- 0.40). REE was comparable in RfA subjects and WnC subjects, while it was sharply decreased (P < 0.01) in the MnA patients both in absolute value and after adjustment for body composition (FFM and FM) or body weight. This cross-sectional study shows that marked changes in BIA parameters occur in undernourished anorectic patients and also in the anorectic subjects who were previously very underweight but studied only after having already regained a normal body size. REE was deeply decreased in the undernourished anorectic women even when the differences in body composition or Wt were taken into account, indicating the occurrence of a significant adaptation of energy expenditure to chronic underfeeding.

Comparison of bioelectrical impedance analysis and dual-energy X-ray absorptiometry for the assessment of appendicular body composition in anorexic women.

OBJECTIVE: To establish the accuracy of bioelectrical impedance analysis (BIA) for the assessment of appendicular body composition in anorexic women. DESIGN: Cross-sectional study. SETTING: Outpatient University Clinic. SUBJECTS: A total of 39 anorexic and 25 control women with a mean (s.d.) age of 21 (3) y. METHODS: Total, arm and leg fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry and predicted from total and segmental BIA at 50 kHz. The predictor variable was the resistance index (Rl), that is, the ratio of height (2) to body resistance for the whole body and the ratio of length(2)/limb resistance for the arm and leg. RESULTS: Predictive equations developed on controls overestimated total, arm and leg FFM in anorexics (P<0.0001). Population-specific equations gave a satisfactory estimate of total and appendicular FFM in anorexics (P=NS) but had higher percent root mean square errors (RMSEs%) as compared to those developed on controls (8% vs 5% for whole body, 12% vs 10% for arm and 10% vs 8% for leg). The accuracy of the estimate of total and leg FFM in anorexics was improved by adding body weight (Wt) as a predictor with Rl (RMSE%=5% vs 8% and 7% vs 10%, respectively). However, the same accuracy was obtained using Wt alone, suggesting that in anorexics, BIA at 50 kHz is not superior to Wt for assessing total and leg FFM. CONCLUSION: BIA shows some potential for the assessment of appendicular body composition in anorexic women. However, Wt is preferable to BIA at 50 kHz on practical grounds. Further studies should consider whether frequencies >50 kHz give better estimates of appendicular composition in anorexics as compared to Wt. SPONSORSHIP: University of Napoli.

Body composition changes in patients with anorexia nervosa after complete weight recovery.

OBJECTIVE: To assess body composition changes occurring in female anorectic patients after complete weight recovery. DESIGN: Longitudinal study. SUBJECTS: : Ten female patients with anorexia nervosa (age at baseline: 19.7+/-5.8 y) were studied both when undernourished (body mass index, BMI 14.8+/-1.3 kg/ m(2)) and after the achievement of a BMI >18.5 kg/m(2). The control group comprised 18 well-nourished women (age 20.1+/-4.4 y; BMI 19.0-23.0 kg/ m(2)). INTERVENTIONS: Fat mass and fat-free mass were determined by dual-energy X-ray absorptiometry. Skinfold thicknesses and circumferences were also measured. Arm muscle area and arm fat area were calculated by standard formulas. RESULTS: The undernourished patients had lower fat-free mass, fat mass, skinfold thicknesses and circumferences. After refeeding, fat mass represented 25-71% (mean 56%) of the mass regained, this percentage being directly related to the extent of weight gain. The increases in skinfolds and circumferences depended upon the site considered and were correlated to a various extent with those in weight or BMI. Skinfolds at biceps and abdominal sites and the waist-to-hip ratio remained significantly higher, whereas arm muscle circumference was significantly lower, in the refed group than in the control one. CONCLUSION: The percentage of fat in the weight regained by refed female anorectic patients was directly related to the extent of body mass increase. Refed anorectic patients appear to preferentially regain fat in the abdominal and triceps regions. Abnormalities in skinfolds (at biceps and abdominal sites), arm muscle area and waist-to-hip ratio still persist in refed anorectic patients in comparison to control healthy controls.

Predictors of survival in terminal-cancer patients with irreversible bowel obstruction receiving home parenteral nutrition.

Clinical, anthropometric, hematologic, and biochemical variables, evaluated immediately before starting nutritional treatment, were related to survival in 76 terminal-cancer patients with irreversible bowel obstruction receiving home parenteral nutrition. At baseline, abnormally low values were observed in the following percentages of patients: 40.8% for body mass index, 59.2% for serum albumin, 84.2% for hemoglobin, 48.7% for lymphocyte count, and 60% for serum cholesterol. Survival on home parenteral nutrition ranged between 6 and 301 d, with a median of 74 d. Hemoglobin, serum albumin and serum cholesterol were lower in patients with a survival of less than 3 mo. With regard to Karnofsky performance status, median survival times were 63 d for a score below or equal to 50 and 128 d for a score between 60 and 70. Albumin and a Karnofsky score above 50 (but not age, weight, body mass index, lymphocyte count, or cholesterol) emerged (with a positive sign) as predictors of survival. In conclusion, terminal-cancer patients with irreversible bowel obstruction are often malnourished, showing a high prevalence of anemia and hypoalbuminemia. Survival differs widely and can be predicted only to a limited extent from initial values of serum albumin and Karnofsky performance status.

The prediction of single-frequency BIA variables from individual characteristics.

To define whether reference values for bioimpedance analysis (BIA) can be predicted in healthy individuals, individual characteristics and BIA variables (resistance index=height(2)/parallel resistance and reactance index= height(2)/parallel reactance) were evaluated in non-obese healthy individuals: 863 men and 769 women with an age range 20-70 years and body mass index (BMI) 19.0-29.9 kg/m(2). The following predictive equations were obtained using multiple regression analysis:Resistance index (cm(2)/ohm)Males 21.06 + 0.087xage + 1.091xweight -1.801xBMI,Females 20.35 + 0.037xage + 0.878xweight - 1.343xBMIReactance index (cm(2)/ohm)Males 0.57 + 0.117xweight - 0.096xBMIFemales 1.42 + 0.078xweight - 0.075xBMIIn conclusion, reference BIA values seem to be reasonably predicted based on individual characteristics.

The prediction of basal metabolic rate in young adult, severely obese patients using single-frequency bioimpedance analysis.

To evaluate whether bioimpedance analysis (BIA) is a useful tool for predicting basal metabolic rate (BMR), sex, age, height, weight, BMI, and single-frequency BIA variables (resistance index and phase angle) were assessed in 61 young adult non-diabetic obese patients (BMI >35 kg/m(2)). BMR was measured by indirect calorimetry. In both sexes BMR significantly correlated with weight, BMI, and resistance index. Using multiple regression analysis, the following prediction equations were derived: (1). considering individual characteristics: BMR (kcal/day)=780+11.4xweight (+221 for men); (2). including also BIA variables: BMR=- 96+8.4xresistance index+8.3xweight+82.5xphase angle. Thus, in young adult, severely obese individuals, BIA variables are significant predictors of BMR.

[Validity of 5 bioelectric impedance equations for the estimation of lean body mass in women]. / Validità di cinque equazioni dell'impedenziometria bioelettrica per la stima della massa corporea magra nella donna.

Fat free mass (FFM) predicted by five bioelectrical impedance (BIA) available formulae (Segal et al., Lukaski et al., Kushner et al., Deurenberg et al., manufacturer's predictive equation) was compared with densitometrically-determined FFM (as a reference method) in two groups of young women with different anthropometric characteristics. In the farmers (very short and light individuals), none of the studied formulae was able to accurately predict FFM: this latter was overestimated in subjects with low and underestimated in those with high FFM. In the other group (INCAP employees), only values predicted by Lukaski formula were in perfect agreement with FFM, showing no bias depending on FFM changes. In conclusion, the available BIA formulae seem to be specific for population from which they were derived and could not be used on samples from other populations if not cross-validated.